2005 Flashcards

Question

``` The recommended preoperative fasting status for infant formula in infants and children is how many hours? A. 2 hours B. 4 hours C. 6 hours D. 8 hours ```

Answer 1

Answer: C Rationale: Gastric emptying is influenced by volume (distention), osmolarity (protein and sugar), fat, and sold vs liquid (fat slows gastric emptying greater than carbohydrates or proteins). Cavell et al reported that the gastric emptying in healthy infants at 1 and 6 months of age was 48 minutes for human milk and 78 minutes for infant formula. There is insufficient evidence but the Task Force supports a fasting period of 6 hours or more before an elective procedure. Reference: Cavell B: Gastric emptying in infants fed human milk or infant formula. Acta Pedaitr Scand 70:639-641, 1981. American Society of Anesthesiologists: Practice guidelines for preoperative fasting and the use of pharmacologic agents to reduce the risk of pulmonary aspiration: application to healthy patients undergoing elective procedures. Anesthesiology 90:896-905, 1999.

Answer 2

Answer: C Rationale: Meperidine is a phenylpiperidine opioid, but differs from other drugs in this category by its atropine-like characteristic with marked tachycardic effects and prominent histamine releasing propensity. This would account for the cutaneous erythema and vasodilative hypotension. Like other phenylpiperidines, it has a strong mu-receptor agonism which can cause significant respiratory depression. Remifentanil is largely devoid of histamine releasing effects which would mitigate against cutaneous erythema, but can cause peripheral vasodilation and hence drop blood pressure with a small amount of reflex increase in heart rate. Remifentanil, like other pure mu receptor agonists, can cause significant respiratory depression. Butorphanol is a mu receptor antagonist and pentazocine is a partial mu receptor antagonist while both are agonists of kappa receptors, hence their limited respiratory depression but significant analgesic properties. Neither of these agonist/antagonist medications exhibits significant histamine releasing propensities. Reference: Stricker J, Laurito C: Opioid Pharmacology, in: Weinberg G (ed.): Basic Science Review of Anesthesiology, McGraw-Hill, New York, 1997 pp. 28-32. Duthie DJ, Nimmo WS: Adverse effects of opioid analgesic drugs. Br J Anaesth 1987;59:61-77.

Answer 3

Answer: D Rationale: A one-compartment model involves administration of an intravenous medication intravascularly, and (relatively rapid) metabolism or elimination causing a more or less linear decrease in plasma drug concentration. A two-compartment model involves both more rapid initial elimination or metabolism of an intravascular drug plus the slower release of a drug into the blood from non-vascular tissues such as muscle or fat, causing a secondary beta phase of more slow decrease in plasma drug concentration by metabolism and/or elimination. The initial rapid pharmacologic onset of opioids is via their rapid initial crossing of the blood/brain barrier. With one bolus administration, many opioids are then rapidly redistributed to other tissues and the central nervous system effects are then ended. However, with continuous infusion or multiple bolus administration, depot storage of an opioid can occur and prolonged opioid effects can be manifest by a two-compartment release of drug over time. However, remifentanyl is so rapidly metabolized by ester hydrolysis that significant depot storage does not occur, and a one- compartment model of pharmacokinetics is approximated, causing rapid emergence from its effects after cessation of administration. Meperidine, morphine, and fentanyl undergo more slow hepatic degradation and follow a two-compartment model. Reference: Alston T: Pharmacokinetics and Drug-Receptor Interactions, in: Weinberg G (ed.): Basic Science Review of Anesthesiology, McGraw-Hill, New York, 1997 pp. 1-7.

Answer 4

Answer: A Rationale: Levallorphan (a structural analog to the mu receptor agonist levorphanol) is an opioid antagonist; and its administration causes competitive binding at mu opioid sites throughout the nervous system. However, levallorphan exhibits mild kappa receptor agonism with analgesic properties. A patient with a heroin addiction may suffer acute withdrawl symptoms with administration of this or other opioid antagonist medications. Other opioid antagonists include naloxone and naltrexone. Tramadol is a synthetic analog of codeine and exhibits weak mu receptor agonism, and is useful for mild to moderate pain. Meperidine is a phenylpiperidine opioid agonist. Propoxyphene is a methadone analog with somewhat less mu agonist activity than codeine. Tramadol, meperidine, and propoxyphene will not precipitate opioid withdrawl. Reference: Gustein H, Akil H: Opioid Analgesics, in: Hardman J, Limbird L (eds.): The Pharmacological Basis of Therapeutics 10th ed., McGraw-Hill, 2001 pp 569-611.

Answer 5

Answer: C Rationale: Fentanyl can cause skeletal (including respiratory) muscle static contraction, especially when given as a bolus dose. This centrally mediated action can occur with bolus administration of any opioid, but is much more common with fentanyl and its cojoiners. If the patient cannot be adequately ventilated, opioid antagonist administration can be used to displace fentanyl from central nervous system binding sites thus this phenomenon, but this may not be advisable in the patient in whom a laryngeal mask airway has been inserted since gagging may result. Administration of a rapidly acting muscle relaxant can effect skeletal (hence respiratory) muscle paralysis and allow ventilation in this scenario. Addition of a volatile anesthetic agent, although causing some skeletal muscle relaxation, would not resolve the respiratory muscle tonic contracture quickly enough. Use of epinephrine for its beta-2 adrenergic effect would do nothing for this patient who is not suffering from bronchial muscle constriction. Insertion of a cuffed endotracheal tube might allow higher peak inspiratory pressure than is possible with a laryngeal mask airway, but would not treat the causative problem. Reference: Stolting R, Miller R: Basics of Anesthesia 4th ed., Churchill-Livingstone, New York, 2000 pp71-73.

Answer 6

Answer: A Rationale: Alfentanil has a potency 1/10th that of fentanyl and is relatively rapidly metabolized by hepatic degradation. These two properties allow relative safety in intermittent bolus administration in a sedation technique, and have made this drug popular as an agent in an outpatient general anesthetic technique. Sufentanil has a shorter alpha half-life (by redistribution) and a shorter beta half life (by hepatic and renal metabolism) than does fentanyl. However, its potency is 10 times that of fentanyl and it is recommended for continuous intravenous infusion only, since a bolus administration of this extremely potent opioid can yield very high peaks of pharmacologic effect and side-effect. Remifentanil is equipotent to fentanyl. However, its rapid onset is associated with bradypnea, trunchal rigidity and bradycardia. Although it has been used as a bolus administration for procedures such as a retrobulbar block it is generally recommended for continuous infusion. Meperidine undergoes slower metabolization and repetitive administration can prolong recovery. Reference: Vezeau PJ: Anesthetic Agent Update, in: Oral and Maxillofacial Surgery Update Vol. 3, AAOMS, 2002.

Answer 7

Answer: B Rationale: A dose of epinephrine greater than 2.1 mcg/kg can induce a dysrhythmia in a patient anesthetized with halothane. Correct dosing of epinephrine with the use of halothane is especially important in the pediatric population. The maximum safe epinephrine dose when halothane is used is generally considered to be 1.0 mcg/kg. Reference: Elamana V: Anesthetic considerations in patients with cardiac arrhythmias, pacemakers and AICDs. International Anes Clin 39(4): 21-42, 2001.

Answer 8

B Rationale: Carbon monoxide, produced as an end product of burning tobacco has 200x greater affinity than oxygen to the Hgb molecule. Carboxyhemoglobin which can be as high as 15%, predisposes a patient to perioperative hypoxia. Pulse oximetry fails to recognize the presence of carboxyhemoglobin as distinct from oxyhemoglobin. Therefore a patient with 10% COHb may display a saturation of 100% when in fact the actual saturation may be closer to 90%. In addition, carboxyhemoglobin has the effect of shifting the oxygen-dissociation curve to the left (less oxygen delivered to tissues). Ventilation, the mechanism of air exchange between the environment and the lungs, is not directly effected by carbon monoxide. Reference: Mardirossan G, Schneider RE, Limitations of pulse oximetry. Anesth Prog 39: 194-196, 1992.

Answer 9

D Rationale: This individual is likely experiencing diabetes insipidus secondary to head trauma. The flattened T- waves are consistent with hypokalemia, however in order to correct his potassium level he should have his magnesium level adjusted as well (with replacement using 1g of MgSO4). Reference: Adam P: Evaluation and management of diabetes insipidus. Amer Fam Physician 55(6), May 1, 1997.

Answer 10

Answer: C Rationale: Midazolam, fentanyl, and propofol all cause a relaxation of the upper airway musculature, a depression of the hypoxic/hypercapneic respiratory drive and a depression of the pharyngeal and laryngeal reflexes. The patient's cough followed by stridorous sounds is suggestive of an irritation of the vocal cords resulting in a laryngospasm. Chest movement without air exchange which is implied may be secondary to upper airway obstruction, however, while this may not be completely relieved by a jaw thrust it would be anticipated that there would be some improvement. Reference: Stoelting RK, Miller RD: Basics of Anesthesia. 2000. New York. Churchill Livingstone. Davison JK, Eckhardt WF, Perese DA: Clinical Anesthesia Procedures of the Massachusetts General Hospital. 1993. Boston. Little, Brown and Company. Ochs MW: Pulmonary complications and their management. Oral Maxillofac Surg Clin North Am; 1992;4:769.

Answer 11

Answer: Rationale: Pediatric patients have anatomic differences that make tracheal intubation more challenging. Their epiglottis is floppy and more difficult to manipulate. Their larynx lies at a more superior level; C3-C4 as opposed to the adult, where lies at C4-C5. This is an important anatomic consideration to have in mind for the correct placement of the ETT and position of the tip. The anterior attachment of the vocal cords is more caudal so they are not perpendicular to the airway as they are in the adults. These factors make it necessary to displace the tongue and mandible more in order to visualize the infant's vocal cords. Therefore, straight laryngoscopes blades are used more commonly to intubate the trachea of children. Reference: Gregory, GA Pediatric Anesthesia 4th edition. Churchill Livingstone, 2002.

Answer 12

B Rationale: A right to left intracardiac shunt will result in less blood perfusing the lungs. This will result in an increase in alveolar partial pressure but also a decrease in arterial partial pressure. A right to left intracardiac shunt could potentially speed up an intravenous induction because venous blood carrying the IV induction agent will return to the heart and bypass the pulmonary circulation, reaching the brain more quickly. A patient with Tetralogy of Fallot is a classic example of a patient with a right to left intracardiac shunt. Functional residual capacity is the volume of lung after the end of a normal TV expiration. A smaller volume will reach a higher anesthetic concentration more quickly than a larger volume. A small functional residual capacity will allow the alveolar concentration to quickly approach the inspired concentration, speeding up induction. Pediatric patients have a small FRC and high alveolar ventilation resulting in more rapid inhalation induction compared to adults. Increasing alveolar ventilation will replace more anesthetic taken up by the pulmonary bloodstream, maintaining a higher alveolar concentration and thus speeding induction. An agent with low blood gas solubility will equilibrate rapidly resulting in a more rapid induction. Reference: Morgan, Mikhail, Murray. Clinical Anesthesiology 2002 Lange/McGraw-Hill. Miller. Anesthesia 5th Ed. 2000 Churchill Livingstone.

Answer 13

Answer: C Rationale: While undergoing a general anesthetic, children without lung disease may lose as much as 45 percent of their FRC. Owing to a higher oxygen consumption and greater loss of FRC in children during general anesthesia, hypoxia develops in a matter of seconds. To compensate for the higher oxygen consumption, children have a higher blood volume per kg or compared to adult-(80-100 cc/kg children and 65-70cc/kg for adults). Children should have their ventilation controlled during anesthesia because hypoventilation exacerbates their tendency toward hypoxia. Atelectasis may occur in mechanically ventilated children, but is more likely to occur in children who breathe spontaneously. Children with pulmonary diseases may lose even more of the FRC, exposing them to increasing ventilation-perfusion mismatch and hypoxia. An increased inspired oxygen concentration and application of positive end-expiratory pressure (PEEP) may partially restore FRC. However, PEEP must be applied carefully. Reference: Gregory, GA Pediatric Anesthesia 4th edition. Churchill Livingstone 2002. Zaglaniczny, K. Clinical Guide to Pediatric Anesthesia. W. B. Saunders Co. 1999.

Answer 14

Answer: B Rationale: Neonates, infants, and children have an increased body surface area relative to weight. Because they cannot shiver to create or maintain body heat they rely on a less efficient process called non-shivering thermogenesis. This process is dependent upon the fact that children have a greater amount of brown fat (so named because of its rich vascular supply) than adults. When the newborn is cold stressed, oxygen consumption will increase and result in the release of norepinephrine (NE). NE will react with the Lipases in the brown fat to breakdown fat into triglycerides. The cascade continues to as triglycerides are metabolized to glycerol and non-esterified fatty acids (NEFA). These NEFA are further degraded under the needed heat generating process to form carbon dioxide and water. Reference: Behrman, Kliegman, Jenson, Nelsons, Textbook of Pediatrics, W.B. Saunders Company:2000. Miller, Anesthesia Fifth Edition, Churchill Livingstone, 2000.

Answer 15

C Rationale: Morbid obesity is defined as a body weight in excess of 100 lbs over ideal weight or a body mass index of 40 or greater. There are a variety of adverse changes associated with obesity. Pulmonary function changes in obese patients suggest restrictive pulmonary disease characteristics. PaO2 is decreased by obesity as a result of ventilation/perfusion mismatches. Despite this, PaCO2 and the ventilatory response to PaCO2 remains normal. Functional residual capacity is decreased and is accentuated by supine positioning and under anesthesia. Reference: Stoelting and Dierdorf: Handbook for Anesthesia and Co-existing disease. Churchill-Livingstone, 2nd ed 2002.

Answer 16

C Rationale: Large doses of prilocaine, generally greater then 600 mg, can result in methemoglobinemia in selected patients. Intravenous doses of articaine have been reported to cause similar problems. This occurs as a result of one of the metabolites of the drug converting reduced hemoglobin to methemoglobin. The patient will experience cyanosis with dark blood. Pulse oximetry remains normal since the monitor mistakenly interprets methemolgobin as oxyhemoglobin but the actual oxygen carrying capacity is decreased resulting in the cyanosis. Small doses of methylene blue ( 1-2 mg/kg) will convert the methemoglobin back to reduced hemoglobin Reference: Stoelting and Miller, Basics of Anesthesia, Churchill Livingstone, 2002

Answer 17

D Rationale: An increase in heart rate is usually the earliest and most consistent sign to be detected. An increase in end-tidal CO2 is usually the most sensitive sign in detecting malignant hyperthermia. While increase temperature and muscle rigidity are hallmark signs of malignant hyperthermia, these manifestations are less sensitive and may not present as early as the tachycardia and elevated end-tidal CO2. Masseter muscle rigidity should be distinguished from skeletal muscle rigidity and occurs early. Reference: Stoelting RK, Dierdorf SF; Handbook for Anesthesia and Co-existing Disease, Churchill Livingston 2nd ed 2002.

Answer 18

A Rationale: Patients who have acute intermittent porphyria do not tolerate barbiturates. The use of these drugs could precipitate an attack, which would present with abdominal pain, tachycardia and hypertension, seizures and autonomic nervous system disorders. Propofol is safe to use. Midazolam and ketamine are probably safe to use. Reference: Stoelting RK, Dierdorf SF; Handbook for Anesthesia and Co-existing Disease, Churchill Livingston 2nd ed 2002.

Answer 19

A Rationale: Vagal maneuvers, such as the Valsava maneuver can be tried first. Vagal maneuvers are most effective if attempted immediately after onset. Adenosine is the first drug of choice if vagal maneuvers are ineffective. Reference: Faust RJ: Anesthesiology Review. 3rd ed Churchill Livingston 2002.

Answer 20

D Rationale: Magnesium should be considered the first drug of choice in the treatment of torsades de pointes. It is administered as magnesium sulfate 1 to 2 grams over 1 to 2 minutes. Traditional anti-arrhythmic therapy is not likely to be successful. Reference: Faust RJ: Anesthesiology Review. 3rd ed Churchill Livingston 2002.

Answer 21

Answer: D Rationale: The patient is presenting with an unstable ventricular tachycardia which is treated with prompt defibrillation. Reference: Handbook of Emergency Cardiovascular Care .2002 ed.

Answer 22

Answer: B Rationale: The position of the inferior alveolar neurovascular bundle is an important determinant in the design of the sagittal split osteotomy. The neurovascular bundle travels just under the facial cortical plate of the mandible. Whether the osteotomy is made with rotary instruments or a reciprocating saw, the vertical cut must be carried just through the cortical plate (i.e. monocortical). The thickness of the bone over the neurovascular bundle is greatest in the area of the second molar. The vertical osteotomy should be placed lateral to the second molar unless circumstances dictate otherwise. Reference: Rajchel J., Ellis E., and Fonseca R.J. The anatomical location of the mandibular canal: its relationship to the sagittal ramus osteotomy. Int J Adult Orthod Orthogn Surg 1:37-47, 1986.

Answer 23

Answer: B Rationale: Bony healing after a fracture or osteotomy consists of four histologically distinct stages: an inflammatory phase, soft callus formation, hard callus formation, and bony maturation/remodeling. During soft callus formation, fibrovascular structures bridge the osteotomized bone segments and there is recruitment of fibroblasts and mesenchymal stem cells within the fracture zone. It is this flexible soft callus which is lengthened via gradual traction during the subsequent distraction phase. Reference: Crago C.A., Proffit W.R., and Ruiz R.L. Maxillofacial Distraction Osteogenesis. Pp. 357-393. Proffit W.R., White R.P., and Sarver D.M. (Eds) Contemporary Treatment of Dentofacial Deformity, Philadelphia. Mosby. 2003.

Answer 24

Answer: D Rationale: In most patients, a latency phase of 5 to 7 days allows for adequate formation of a soft callus before active distraction is initiated. If activation of the distractors is initiated too early, decreased bone formation results. If the latency period is too long, conversion to a hard callus begins and early healing of the osteotomy will prevent mandibular lengthening. In young children, bone healing occurs much faster and little or no latency phase is required. Reference: Crago C.A., Proffit W.R., and Ruiz R.L. Maxillofacial Distraction Osteogenesis. Pp. 357-393. In: Proffit W.R., White R.P., and Sarver D.M. (Eds), Contemporary Treatment of Dentofacial Deformity. Philadelphia. Mosby. 2003.

Answer 25

Answer: D Rationale: The Steiner analysis is a cephalometric approach utilized to directly evaluate the protrusion of the upper and lower incisors. The position of the maxillary and mandibular incisors is related to Nasion-A point (N-A) and Nasion-B point (N-B) lines using both angular and linear measurements. Within this analysis, the “Holdaway Ratio” is used to evaluate the prominence of the mandibular incisors and bony chin. The ratio is calculated by comparing the distance of the lower incisor edge and pogonion to the N-B line. Ideally, the Holdaway Ratio should be approximately 1.0 in males and 0.5 to 1.0 in females. This relationship is useful in planning for genioplasty. Reference: Proffit W.R., Sarver D.M. Diagnosis: Gathering and Organizing the Appropriate Information. Pp. 127- 170. In: Proffit W.R., White R.P., and Sarver D.M. (Eds) Contemporary Treatment of Dentofacial Deformity, Philadelphia. Mosby. 2003.

Answer 26

Answer: A Rationale: One of the technical considerations that must be considered when choosing a specific procedure for mandibular setback surgery is the actual shape of the mandibular arch form and rami. In patients with a “U” shaped mandible, either bilateral sagittal split osteotomies (BSSO) or a transoral vertical ramus osteotomy may be utilized for mandibular setback in Class III patients. When the mandible is “V” shaped with flared rami, then the procedure that results in the least condylar width change is the transoral vertical ramus osteotomy. If a patient with a “V” shaped mandible undergoes BSSO, a gap is created posteriorly between the cortical plates of the proximal and distal segments. If lag screws are used for rigid fixation, the gap is closed and there is narrowing of the intercondylar width. Reference: Tucker M.R. Surgical correction of mandibular excess: technical considerations for mandibular setbacks. Atlas Oral Maxillofac Surg Clin North Am. 1993 Mar;1(1):29-39.

Answer 27

Answer: A Rationale: The lingula and inferior alveolar foramina are located in a more superior and posterior position in this age group. This has technical implications in determining the vertical placement of the medial osteotomy of the ramus. If the medial bone cut is positioned high on the ramus, then injury to the nerve is avoided , but the risk of unfavorable split (i.e. buccal plate fracture) increases. In children, the sagittal component of the osteotomy design should be placed as far laterally as possible in order to avoid injury to the developing teeth. Children will have a higher propensity for “greenstick” fracture along the inferior border of the mandible. Their bone is more cancellous in nature and this often results in a longer area of fracture along the inferior border of the mandible. Developing third molars can be removed after the mandibular ramus has been split. In cases where the third molar teeth are only partially developed, they can still be enucleated while the proximal and distal segments are separated Reference: Bell WH: Mandibular Advancement in Children Special Considerations. In Bell WH, Modern Practice in Orthognathic and Reconstructive Surgery, Vol. 3, 1992, WB Saunders, pp. 2516.

Answer 28

Skeletal anterior open bite (i.e. apertognathia) is the result of a maxillary growth problem and is frequently associated with a concomitant transverse maxillary discrepancy. The use of a total mandibular subapical osteotomy for correction of an anterior open bite requires counterclockwise movement of the dentoalveolar segment, does not address the maxillary deformity, and is associated with a high rate of skeletal relapse. Appropriate management of apertognathia requires correction of the maxillary problem usually consisting of segmental Le Fort I level surgery. The use of the total mandibular subapical osteotomy is limited to correction of malocclusions that can be addressed by repositioning the mandibular alveolar process only. The subapical osteotomy does not change the anatomical position of the mandibular body or symphysis. As a result, application of the total mandibular subapical osteotomy is limited to situations where there is retrusion of the dentoalveolar process with an otherwise normal facial morphology. Reference: Frost DE: Orthognathic Surgical Techniques. In Ward-Booth et al, Maxillofacial Surgery. Vol. 2, 1999, Harcourt Brace. pp. 1291.

Answer 29

Answer: C Rationale: Le Fort I level osteotomy may be complicated by intraoperative malpositioning of the maxillomandibular complex after the jaws have been wired together. Pressure applied to the chin may bring the maxillary osteotomy together while unintentionally displacing the mandibular condyles. This is often caused when bony interferences along the posterior maxilla exist. Reference: Bays R.A. Complications of Orthognathic Surgery. In: Kaban L.B., Pogrel M.A., and Perrott D.H. (Eds), Complications in Oral and Maxillofacial Surgery. W.B. Saunders, Philadelphia, pp. 193-221. 1997.

Answer 30

Answer: B Rationale: Transverse expansion of the maxillary arch is often complicated by lack of long term stability. This is especially true when large movements are undertaken. As transverse relapse occurs, the lingual cusps of the maxillary posterior teeth move along the lingual inclines of the lingual mandibular cusps and the anterior open bite deformity is recreated. Reference: Long Face Problems in Contemporary Treatment of Dentofacial Deformity. Eds. Proffit WR, White RP, Sarver DM. Mosby 2003. Page 491.

Answer 31

Answer: D Rationale: Bleeding during Le Fort I osteotomy and downfracture is usually the result of injury to the terminal branches of the internal maxillary artery including the descending palatine and sphenopalatine arteries. Even after the Le Fort I downfracture, intraoperative injury to the descending palatine vessels may occur as a result of significant maxillary advancement or impaction. Postoperative hemorrhage following maxillary surgery typically presents as epistaxis with bleeding into the anterior and/or posterior nasal cavity. This may occur at any point during the first month after the surgical procedure and may be the result of breakdown of previous clot or necrosis of arterial vessels which were stretched by the surgical movement. An initial “sentinel” episode of brisk bleeding may stop spontaneously giving the false impression that the problem has resolved. Angiography and interventional radiology techniques provide detailed visualization and localization of the source of bleeding. The bleeding vessel may be stopped by embolization without the need to reopen the wound, remove rigid fixation devices, and dismantle skeletal segments. Angiography also allows detailed visualization of the arterial system and detection and management of pseudoaneurysm involving the internal maxillary artery or its terminal branches. Reference: Preoperative, intraoperative and postoperative care in Fonseca Oral and Maxillofacial Surgery, Saunders 2000. Page 187.

Answer 32

Answer: B Rationale: The pterygoid plexus of veins is located directly posterior and medial to the maxilla. Its location makes it vulnerable to injury during creation of the osteotomy and use of an osteotome for pterygomaxillary disjunction. It is the most common source of intraoperative venous hemorrhage in patients undergoing LeFort I osteotomy. Management of venous hemorrhage from the pterygoid plexus requires packing and application of topical hemostatic agents. Reference: Lanigan DT: Vascular Complications Associated with Orthognathic Surgery. Oral and Maxillofacial Surgery Clinics of North America. Volume 9, Number 2, May 1997. pp. 232.

Answer 33

Answer: A Rationale: Radiographic assessment of the hand-wrist anatomy has been utilized to estimate a patient's skeletal age when early orthodontic or surgical treatment is contemplated. The theoretical basis is that the chronology of ossification in the bones of the hand and wrist can be related to the rest of the skeleton. The relationship between the bony development of the hand-wrist complex and the facial skeleton is not well correlated. Recently, the radiographic assessment of the cervical spine vertebrae for estimating skeletal development has been proposes. Although not perfect, the use of cervical spine development as an indicator of skeletal age is better correlated with the facial skeleton and the adolescent growth spurt. This technique has the additional advantage that no additional radiographs are required since the cervical vertebrae are visible on a cephalometric radiograph. Reference: Franchi L., Baccetti T, McNamara JA Jr. Mandibular growth as related to cervical vertebral maturation. Am J Orthod Dentofac Orthop 118: 335-340. 2000.

Answer 34

Answer: D Rationale: Segmental surgery for transverse maxillary expansion is associated with the highest rate of relapse following orthognathic surgery. Palatal soft tissue resistance and dental compensations often add to this instability. Reference: Proffit WR, Turvey TA, Phillips C: Orthognathic Surgery A Hierarchy of Stability. Intl J Adult Orthod Orthognath Surg. 11:191-204, 1996.

Answer 35

Extraction of maxillary first premolars in this clinical situation allows for adequate space for alignment of crowded maxillary incisors. The space created allows for correction of inclination for teeth that have drifted forward during development of dental compensations. As the maxillary first premolar spaces are closed, the anterior teeth are retracted maximizing the degree of maxillary skeletal advancement. In Class III patients undergoing presurgical orthodontic treatment, extraction of mandibular first premolars is rarely indicated. This is because closure of the extraction spaces will require retraction of the anterior teeth resulting in less favorable tooth-lip balance. Extraction of the second mandibular premolars provides the necessary space for alleviation of crowding while avoiding retraction of the incisors. Reference: Bailey L.J., Sarver D.M., Turvey T.A., and Proffit W.R. Class III Problems. In: Contemporary Treatment of Dentofacial Deformity. Eds. Proffit WR, White RP, Sarver DM. Mosby 2003.

Answer 36

Answer: D Rationale: Passavant's ridge is a soft tissue prominence which extends into the pharynx. The structure is usually described in association with cleft palate, but has been described in many normal subjects. The soft tissue structure also frequently contributes positively to velopharyngeal closure. The ridge usually forms along the superior border of the superior pharyngeal constrictor muscle, but its exact position on the posterior pharyngeal wall may vary. Reference: The Nature of the Velopharyngeal Mechanism. In: McWilliams B.J., Morris H.L., and Shelton R.L. (Eds), Cleft Palate Speech. B.C. Decker, Philadelphia, Pp. 197-235, 1990.

Answer 37

Answer: D Rationale: Preservation of an anterior buccal mucosal pedicle is critical to preserving blood circulation to the premaxilla in patients that have not undergone previous bone graft reconstruction of bilateral cleft defects. A circumvestibular incision in the ungrafted bilateral cleft lip and palate patient would lead to aspectic necrosis of the premaxillary segment. Maxillary advancement in these patients is carried out through separate right and left vestibular incisions with limited tunneling anteriorly. A small vertical incision within the midline may be utilized for separation of the nasal septum and mobilization of the premaxillary segment. Reference: Turvey TA, Vig K, Fonseca RJ. Maxillary Advancement and Contouring in The Prescence of Cleft Lip and Palate. In Turvey et al Facial Cleft and Craniosynostosis, 1996 WB Saunders. pp. 460.

Answer 38

Answer: B Rationale: Isolated cleft palate is associated with an underlying syndrome more frequently (as much as 50%) than cleft lip and palate. Stickler syndrome has been identified as the most common diagnosis causing both cleft palate and Robin sequence. Patients with Stickler syndrome demonstrate a collagen metabolism disorder. Relevant clinical findings include early myopia and an increased risk of retinal detachment which may go un-noticed early in life. It is recommended that infants with an isolated cleft of the secondary palate undergo formal ophthalmologic evaluation at some point during their first year of life. van der Woude syndrome can be caused by deletions in chromosome band 1q32, and linkage analysis has confirmed this chromosomal locus as the disease gene site. van der Woude syndrome is an autosomal dominant syndrome typically consisting of a cleft lip or cleft palate and distinctive pits of the lower lips. The degree to which individuals carrying the gene are affected is widely variable, even within families. These variable manifestations include lip pits alone, absent teeth, or isolated cleft lip and palate of varying degrees of severity. Other associated anomalies have also been described. About 1-2% of patients with cleft lip or palate have van der Woude syndrome. Velocardiofacial syndrome (VCFS) is a genetic condition characterized by structural or functional palatal abnormalities, cardiac defects, unique facial characteristics, hypernasal speech, hypotonia, developmental delay, and learning disabilities. As many as 15-20% of patients have Robin sequence. Reference: Wyszynski, DF, Cleft Lip and Palate in Origin to Treatment. Oxford University Press, 2002.

Answer 39

Answer: A Rationale: The von Langenbeck palate repair technique involves the creation of two full thickness mucoperiosteal flaps with care taken to preserve anterior soft tissue pedicles. The theoretical advantage of the anterior soft tissue attachments is additional blood supply for the elevated flaps. During the Bardach (2-flap) and pushback procedures, similar soft tissue flaps are elevated, but no anterior pedicle is maintained. The Furlow procedure involves the use of double opposing Z-plasties with the musculature elevated with the posteriorly based flaps on the nasal and oral sides. Reference: Posnick JC: The Staging of Cleft Lip and Palate Reconstruction Infancy Through Adolescence. In Posnick JC Craniofacial and Maxillofacial Surgery in Children and Young Adults. pp. 804.

Answer 40

Answer: C Rationale: The goals of cleft palate repair are twofold; first, water tight closure of the oral-nasal communication, and second, the creation of a dynamic soft palate for normal speech production. The most important muscular component of the soft palate is the levator veli palatini muscle which functions to elevate the velum and allow for appropriate speech production. In patients with an unrepaired cleft palate, the levator musculature is clefted and has abnormal insertions along the posterior edge of the hard palate. Reference: Cutting, CB, Rosenbaum J, Rovati L: The technique of muscle repair in the cleft soft palate. Operative Techniques in Plastic and Reconstructive Surgery, Vol 2, No 4(November), 1995: pp 215-222

Answer 41

Answer B Rationale: Generally, cleft lip repair is carried out when the child is 10 to 12 weeks of age. General guidelines were developed for reduction of anesthetic risk and suggested that the surgery be undertaken when the child is approximately 10 weeks of age, weighs at least 10 lbs, and has a serum hemoglobin of at least 10 mg/dl. This has often been referred to as the “rule of 10's” for the timing of cleft lip repair. Reference: Posnick JC: The Staging of Cleft Lip and Palate Reconstruction Infancy Through Adolescence. In Posnick JC Craniofacial and Maxillofacial Surgery in Children and Young Adults. pp. 798.

Answer 42

Answer: C Rationale: Two-flap palatoplasty techniques involve the elevation of full-thickness mucoperiosteal flaps on each side of the cleft defect for oral side closure. After the nasal mucosa is closed, these soft tissue flaps are sutured together in the midline for closure of the cleft defect. During the initial dissection and elevation of the flaps, the greater palatine neurovascular bundles are identified and protected. The result is that the axial soft tissue flaps are raised based upon the blood supply of the greater palatine arteries bilaterally. If the greater palatine artery is injured or cauterized, then the axial pattern soft tissue flap becomes a random pattern flap (i.e. not based on one specific arterial supply) with perfusion from the palatal soft tissue attachments. Reference: Bardach J: Two-flap palatoplasty: Bardach's technique. Operative Techniques in Plastic and Reconstructive Surgery, Vol 2. No 4(November), 1995: pp 211-214.

Answer 43

Answer: C Rationale: By definition, secondary bone graft reconstruction is carried out after the initial closure of the hard and soft palate. Generally, bone grafting is performed between 6 and 10 years of age, but the specific timing is based upon the child's dental development instead of chronological age. Bone graft reconstruction of the cleft maxilla is undertaken based on the development of the permanent maxillary canine tooth. If partial eruption of the canine is allowed prior to bone graft placement, unfavorable periodontal outcome results. Reference: Ochs MW: Alveolar Cleft Bone Grafting(Part II): Secondary Bone Grafting, J Oral Maxillofac Surg 54: 83-88, 1996.

Answer 44

Answer: C Rationale: A superiorly based pharyngeal flap is commonly used for the management of velopharyngeal insufficiency related to cleft palate. A soft tissue flap is developed from the posterior pharyngeal wall. This is done by elevating the posterior pharyngeal wall soft tissues including the superior constrictor muscle off of the prevertebral fascia. This flap is then inset within the soft palate nasal side closure. Reference: Ilankovan V: Secondary cleft lip and palate repair. Operative Maxillofacial Surgery. Chapman and Hall 1998. pp215.

Answer 45

Answer: D Rationale: Cleft lip with or without cleft palate is a common congenital malformation with an incidence of approximately 1 in 700 live births, but significant variation is encountered when different ethnic/racial populations are examined. African Americans have an incidence which is significantly lower than the general population while Asians have the highest rate of birth prevalence. By contrast, isolated cleft palate has a lower overall incidence of approximately 1 in 2,000 live births with similar distribution among the different racial and ethnic populations. Reference: Costello BJ, Ruiz RL. Cleft Lip and Palate: Comprehensive Treatment Planning and Primary Repair. In: Miloro M, Ghali GE, Larsen PE, and Waite PD (Editors): Peterson's Principles of Oral and Maxillofacial Surgery, Second Edition. BC Decker. Hamilton. 2004. Pp: 839-858.

Answer 46

Answer: A Rationale: The superiorly based pharyngeal flap remains the standard approach for surgical management of patients with velopharyngeal insufficiency after cleft palate repair. The procedure involves the creation of a soft tissue flap from the posterior pharyngeal wall which is subsequently inset within the soft palate. The result is that the size of the nasopharyngeal cavity is decreased. The larger nasopharyngeal opening which could not be completely closed by the patient is instead converted into two (right and left) smaller lateral pharyngeal ports. Closure of these ports is easier for the patient to accomplish as long as adequate lateral pharyngeal wall motion is present. Reference: Argamaso R V: Pharyngeal Flap Surgery for Velopharyngeal Insufficiency, Operative Techniques in Plastic and Reconstructive Surgery, Vol 2, No 4 (November), 1995: pp 233-238

Answer 47

Answer: B Rationale: The dynamic sphincter pharyngoplasty procedure involves the use of two superiorly based myomucosal flaps created within each posterior tonsillar pillar. Each flap is elevated with care taken to include as much of the palatopharyngeous muscle as possible. The flaps are then attached to each other and inset within a horizontal incision on the posterior pharyngeal wall. The goal of this procedure is to create a single nasopharyngeal port that has a contractile ridge posteriorly in order to improve velopharyngeal closure. Reference: Gray SD, Pinborough-Zimmerman J: Diagnosis and Treatment of Velopharyngeal Incompetence. Facial Plastic Surgery Clinics of North America. 4:3 (August) 1996: pp. 405-413.

Answer 48

Answer: C Rationale: In contrast to cleft lip and palate, there is a female predominance of cleft palate. The ratio is approximately 3:2. Reference: Wyszynski, DF, Cleft Lip and Palate From Origin to Treatment. Oxford University Press, 2002.

Answer 49

Answer: A Rationale: Ideally, one balances the need for an intact palate for normal speech production with the least interference of maxillary growth. Typically, children will begin to make purposeful speech at approximately 9 to 12 months of age. Most cleft palate centers recommend cleft palate repair between the ages of 9 and 18 months with the exact timing based upon the child's language development as opposed to chronologic age. In a child who reaches an articulation age that requires an intact palate, failure to close the cleft leaves them vulnerable to the development of maladaptive speech patterns which are then difficult to break. Reference: Posnick JC: The Staging of Cleft Lip and Palate Reconstruction Infancy Through Adolescence. In Posnick JC Craniofacial and Maxillofacial Surgery in Children and Young Adults. Pp 803-805.

Answer 50

Answer: A Rationale: The presence of an unrepaired cleft palate causes difficulty with feeding due to the inability to form an adequate seal between the tongue and palate. The cleft defect prevents the infant from creating negative pressure needed to suck fluid from a bottle. Specialized feeding devices typically combine oversized nipples with reservoir spaces and large openings, a squeezable bottle to push fluid into the nipple assembly, and a one-way valve that allows the bolus of fluid to pass from the bottle to the nipple in order to minimize the amount of work the child must perform to feed. Infants should be positioned upright during feeding in order to facilitate management of the fluid bolus and secretions. Obturators for feeding have been used as feeding aids, but their value is not established. Their use has no effect on the infant's ability to generate suction. The parent still must provide assisted feeds, and in infants with retrognathia and posteriorly positioned tongues, they create the risk of airway occlusion. Additionally, they must be monitored and adjusted frequently, making them both expensive and time consuming. Reference: Costello BJ, Ruiz RL. Cleft Lip and Palate: Comprehensive Treatment Planning and Primary Repair. In: Miloro M, Ghali GE, Larsen PE, and Waite PD (Editors): Peterson's Principles of Oral and Maxillofacial Surgery, Second Edition. BC Decker. Hamilton. 2004. Pp: 839-858.

Answer 51

Answer: C Rationale: Hemifacial microsomia is associated with several soft tissue anomalies in addition to the common skeletal manifestations. These include, but are not limited to, microtia, facial nerve palsy, skin tags, soft tissue and muscular hypoplasia, microphthalmos, and macrostomia. Reference: Turvey, TA, Vig, KWL, Fonseca RJ, Facial Clefts and Craniosynostosis Principles and Management. WB Saunders, 1996.

Answer 52

Answer: D Rationale: Distraction osteogenesis has not been proven to provide significant advantages when one looks at post- operative stability or velopharyngeal insufficiency. Similar results have been seen when compared with studies done after traditional orthognathic surgery. There is no difference in orthodontic finishing requirements, and additional compensation may be required when compared with traditional techniques. During the consolidation phase, appliances (either internal or external) are kept in place for several months. Reference: Turvey TA, Ruiz RL, and Costello BJ. Orthognathic surgery in the cleft patient. In: Oral and Maxillofacial Surgery Clinics of North America: Secondary Cleft Surgery. Philadelphia: W.B. Saunders, 14: 491-507, 2002

Answer 53

Answer: D Rationale: The facial deformities associated with hemifacial microsomia are heterogeneous and demonstrate extreme variability of expression. Previous work by Poswillo suggested that early vascular disruption of the developing stapedial artery with expanding hematoma during intrauterine development resulted in destruction of differentiating tissues within the first and second branchial arches. Reference: Poswillo D.E. The pathogenesis of the first and second branchial arch syndrome. Oral Surg 35:302, 1973. Kaban LB. Congenital Abnormalities of the Temporomandibular Joint. In: Kaban LB, Troulis M. (Eds.): Pediatric Oral and Maxillofacial Surgery, pp302-339. WB Saunders, Philadelphia, 2004.

Answer 54

Answer: D Rationale: Orbital hypotelorism with trigonocephalic skull deformity and absence of the nasal cavity and nasal bones are among the skeletal deformities frequently seen in infants with holoprocencephaly. Abnormal development of the premaxillary segment is also encountered and may result in a midline cleft or the characteristic single central incisor within a hypoplastic premaxilla. Mandibular morphology is normal. Reference: Schendel S.A., Tessier P., and Tulasne J.F. Facial Clefting Disorders and Craniofacial Synostosis: Skeletal Considerations. In: Turvey T.A., Vig K.W.L., and Fonseca R.J. (Eds), Facial Clefts and Craniosynostosis: Principles and Management. W.B. Saunders, Philadelphia, Pp. 95-128. 1996.

Answer 55

Answer: C Rationale: Metopic suture craniosynostosis results in a classic trigonocephalic skull dysmorphology. Because the metopic suture is absent and growth perpendicular to this region is arrested, there is a characteristic triangular shaped anterior skull. In addition, patients demonstrate horizontally retrusive lateral orbital rims and hypotelorism. Reference: Ghali GE, Sinn DP. Nonsyndromic Craniosynostosis. In: Miloro M, Ghali GE, Larsen PE, and Waite PD (Editors): Peterson's Principles of Oral and Maxillofacial Surgery, Second Edition. Hamilton, BC Decker, 2004. Pp: 887-900.

Answer 56

Answer: A Rationale: In untreated patients with more than one cranial vault suture affected, the likelihood of increased intracranial pressure exceeds 40 %. Despite this increased risk, signs of increased ICP are rarely seen prior to one year of age. Primary cranio-orbital decompression is typically undertaken at some point prior to one year of age. Reference: Posnick JC, Ruiz RL, and Tiwana PS. Craniofacial Dysostosis Syndromes: Staging of Reconstruction. In: Miloro M, Ghali GE, Larsen PE, and Waite PD (Editors): Peterson's Principles of Oral and Maxillofacial Surgery, Second Edition. Hamilton, BC Decker, 2004. Pp: 901-929.

Answer 57

Answer: C Rationale: The monobloc operation allows the surgeon to simultaneously advance the midface and fronto-orbital units through a transcranial approach for correction of the total midface deficiency characteristic of Crouzon syndrome. The facial bipartition procedure consists of the same surgical steps as the monobloc performed in combination with the removal of a section of bone from the midline. Because it allows correction of orbital hypertelorism, bipartition is often the procedure of choice for correction of the orbital and midfacial deformity associated with Apert syndrome. Reference: From Ruiz RL, Turvey TA, Tiwana PS: Monbloc and Facial Bipartition Osteotomies. Atlas of Oral and Maxillofacial Surgery Clinics of North America. Number 10, March 2002. pp 131-148.

Answer 58

Answer: C Rationale: Patients with Treacher Collins Syndrome frequently require bone grafts for construction of missing and hypoplastic orbital-zygomatic structures. Early surgery should be avoided since ongoing orbital growth may make the surgical outcome less predictable. Orbital structures are almost their adult size by approximately age 7. This makes late childhood the ideal time for construction of orbital and zygomatic components. If surgical correction of the orbital-zygomatic deformity is undertaken during infancy or early childhood, then subsequent growth may adversely effect the outcome. Reference: Waitzmann AA, Posnick JC, Armstrong D, et al. Craniofacial skeletal measurements based on computed tomography: II. Normal values and growth trends. Cleft Palate Craniofacial Journal 29:118, 1992.

Answer 59

Answer: A Rationale: The pediatric cranial vault contains a number of diploic channels. As the cranium is exposed and craniotomy is completed, it becomes possible for air to enter the venous circulation and travel to the pulmonary vasculature. In children with a patent foramen ovale, air may also cross from the right to the left side of the heart and eventually enter the systemic, including cerebral, circulation. Air emboli may result in pulmonary hypertension, impaired coronary blood flow, and stroke. The earliest clinical sign of air embolism during a transcranial procedure is a decrease in end tidal CO2. This is often followed by hypotensive crisis. Reference: Krane EJ, Domino KB. Anesthesia for Neurosurgery. In: Motoyama EK, Davis PJ (Editors): Anesthesia for Infants and Children. Philadelphia, Mosby, 1996, Page 552.

Answer 60

Answer: C Rationale: The Kaban classification system is utilized to describe the mandibular skeletal defect associated with hemifacial microsomia. The Type I skeletal deformity is characterized by a mandibular condyle-ramus complex that is normal in morphology, but hypoplastic. Type IIa patients demonstrate an abnormally shaped ramus with more pronounced hypoplasia of the condyle and temporomandibular joint structures. In Type IIb, the deformity of the ramus is more severe and the condyle is severely hypoplastic and malpositioned. The Type III deformity consists of complete absence of the TMJ and ramus. Reference: Kaban LB. Congenital Abnormalities of the Temporomandibular Joint. In: Kaban LB and Troulis M. (Editors): Pediatric Oral and Maxillofacial Surgery. Philadelphia, WB Saunders, 2004, Page 302.

Answer 61

Answer: A Rationale: All infants born with Apert syndrome demonstrate facial findings consistent with the other craniofacial dysostosis syndromes including craniosynostosis and total midfacial deficiency. In addition, patients with Apert syndrome have a high incidence of other anomalies including cleft palate, deafness, developmental delay, bilateral complex syndactyly of the fingers and toes, and other skeletal anomalies. Reference: Apert Syndrome: Evaluation and Staging of Reconstruction. In: Posnick JC. (Editor). Craniofacial and Maxillofacial Surgery in Children and Young Adults. Philadelphia, WB Saunders, 2000, Page 308.

Answer 62

Answer: D Rationale: Although most patients with repaired cleft palate who undergo maxillary advancement tolerate the change in soft palate position, a minority of patients will demonstrate a deterioration of velopharyngeal function and hypernasality. When it does occur, velopharyngeal insufficiency typically resolves with a return to the patient's presurgical baseline by 6 months. It is prudent to delay subsequent surgery to reduce nasality for at least 6 months following maxillary advancement as most patients will not require surgical intervention. Reference: Turvey TA, Ruiz RL, Vig KWL, and Costello BJ. Orthognathic Surgery in the Patient with Cleft Palate. In: Miloro M, Ghali GE, Larsen PE, and Waite PD (Editors): Peterson's Principles of Oral and Maxillofacial Surgery, Second Edition. Hamilton, BC Decker, 2004. Page 1274.

Answer 63

Answer: B Rationale: The “C” flap is a soft tissue flap developed along the non-cleft side that may be utilized for a number of purposes depending on the anatomy of a particular cleft defect. Specific uses include nostril sill construction or lengthening of the lip. Reference: Millard, DR Cleft Craft: The Evolution of Its Surgery, Volume I: The Unilateral Deformity, Little, Brown , and Company, 1976.

Answer 64

Answer: A Rationale: Bone graft reconstruction of the cleft maxilla and palate is typically accomplished with the use of fresh, autogenous corticocancellous bone grafts harvested from the anterior iliac crest. Other bone harvest sites include the cranial vault and tibia. Necrosis and loss of a small bone fragment is a relatively common occurrence after bone graft repair of the cleft maxilla. In the absence of severe infection, management is conservative consisting primarily of local wound care measures such as frequent irrigation and hygiene. Many patients may loose several small bone fragments and still go on to heal an adequate amount of bone to accomplish the goals of cleft repair. Reference: Padwa, B, Mulliken J OMS Clinics of North America Vol 15. Elsevier, 2003.

Answer 65

Answer: D Rationale: The goals of bone graft reconstruction in patients with cleft lip and palate include: • • • • Providing adequate bony matrix for the developing teeth (e.g. canine and lateral) Closure of any residual oronasal fistula(s) Create alveolar ridge continuity Improve bony support for the nasal base on the cleft side. In patients with bilateral deformities, there is an additional goal of stabilizing the mobile premaxillary segment. Reconstruction of the bilateral cleft defects consolidates the maxillary arch into a continuous bony structure and enhances orthodontic stability. Reference: Larsen PE. Reconstruction of the Alveolar Cleft. In: In: Miloro M, Ghali GE, Larsen PE, and Waite PD (Editors): Peterson's Principles of Oral and Maxillofacial Surgery, Second Edition. Hamilton, BC Decker, 2004. Page 859-860.

Answer 66

Answer: A Rationale: Changes in intercondylar width may occur as a result of sagittal split osteotomy. As the distal segment is advanced, there is often the creation of a gap at the anterior-superior extent of the osteotomy site. If the segments are compressed together at the time of rigid fixation placement, there is a fulcrum based on the distal segment and lateral displacement of the condyle. Several techniques have been described in order to avoid unfavorable condylar displacement. These include the use of bicortical position screws, placement of bone shim between the proximal and distal segments, recontouring of the proximal/lingual aspect of the distal segment, and addition of a midline/symphyseal osteotomy. Use of lag screw fixation will compress the segments and actually cause lateral condylar displacement. Alternatively, lag screws may be utilized only when at least one position screw is placed first in order to maintain the anterior osteotomy gap. Reference: Tucker M.R., Frost D.E., and Terry B.C. Mandibular Surgery. In: Tucker M.R., Terry B.C., White R.P., and VanSickels J.E. (Eds), Rigid Fixation for Maxillofacial Surgery. J.B. Lippincott, New York, Pp. 251- 295, 1991.

Answer 67

Answer: A Rationale: Treacher Collins Syndrome is an autosomal dominant disorder affecting the hard and soft tissues of the 1st and 2nd branchial arches. It is commonly associated with a number of findings including malar hypoplasia with clefting of the zygomatic arches, mandibular hypoplasia with condyle-ramus anomalies, apertognathia, and hearing loss. Craniosynostosis, partial anodontia, and bifid nose are not associated with this disorder. Reference: Posnick JC: Treacher Collins Syndrome Evaluation and Treatment. In Posnick JC Craniofacial and Maxillofacial Surgery in Children and Young Adults. pp. 391

Answer 68

Answer B Rationale: Females approach facial skeletal maturity at approximately 14 to 16 years of age. This is sooner than what is observed in males who reach completion of jaw growth at approximately 18 years of age. Reference: Proffit WR. Contemporary Treatment of Dentofacial Deformity. Philadelphia, Mosby, 2003.

Answer 69

Answer: D Rationale: The concept of arthrotomy for disc repair was championed by McCarty and Farrar with their 1979 report of 327 disc repairs. In spite of reports describing successful outcomes, few reports have evaluated disc position following “repair.” Montgomery, et al imaged 35 joints an average of 2 years after disc repair and noted that disc position was unchanged in 86% of joints, worse in 6%, and improved in 8%. Assuming that these discs were repositioned at the time of surgery, these data suggest that disc position is prone to relapse at some point after disc repair. A smaller series of 23 joints showed persistent disc displacement in 48% of joints after disc repair. Reference: Montgomery MT, Gordon SM, Van Sickels JE, et al. Changes in signs and symptoms following temporomandibular joint disc repositioning surgery. J Oral Maxillofac Surg 50:320, 1992 McCarty WL, Farrar WB: Surgery for internal derangements of the TM joint. J Prosth Dent 42: 191, 1979 Westesson PL, Cohen JM, Tallents RH: Magnetic resonance imaging of TM joint after surgical treatment of internal derangement. Oral Surg Oral Med Oral Pathol 71, 407, 1991

Answer 70

Answer: C Rationale: Glutamate is the primary neurotransmitter for pain. It is the first agent released following trauma. Substance-P plays a major role in pain however it requires higher intensity stimulation for release compared to glutamate. Inflammatory messengers such as PGI2 and serotonin act through the activation of adenylate cyclase sensitive nocioceptive terminals. Reference: Merrill, RL; Neurophysiology of orofacial pain. Oral Maxillofac Clinic North Am. 12:169, 2000

Answer 71

Answer: B Rationale: Condylotomy has been shown to work most favorably in cases of anterior disc displacement, especially in the setting of disc displacement with reduction. Modified condylotomy can effect disc reduction and alter favorably the natural course of internal derangement in reducing disc displacement. Reference: Nickerson, JW: Condylotomy in surgery of the temporomandibular joint. Oral Maxillofac Clinic North Am. 1:315-316 1989

Answer 72

Answer: B Rationale: Puncture landmarks for arthrocentesis are established with reference to a line connecting the tragus and lateral canthus. The initial puncture should be 10 mm anterior to the tragus and 2 mm below the canthal- tragal line. Reference: Israel HA: Kendell BD, Frost DE: Arthrocentesis. Atlas of Oral and Maxillofac Surg Clin North Am. 4:1, 1996.

Answer 73

Answer: C Rationale: Trigeminal sensory nerves relay mechanical, thermal, chemical, and proprioceptive information from craniofacial regions. The trigeminal spinal nucleus is divided into oralis, interpolaris, and caudalis subdivisions. The subnucleus caudalis is the largest subdivision and is primarily responsible for facial pain. Reference: Okeson, J: Management of Temporomandibular Joint Disorders and Occlusion, 4th edition. Mosby, 1998, p34

Answer 74

Answer: D Rationale: In contrast to vascular headache, muscle contraction type headache is usually not associated with visual symptoms, prostration and nausea. Muscle contraction headache can be acute or chronic and is associated with sustained contraction of skeletal muscles. The temporalis muscle is often involved in muscle contraction headache. Symptoms are usually generalized with the sensation of a “constricting band” about the head. The pain of muscle contraction headache is described as dull and throbbing in nature. Unilateral, pulsating headache associated with prostration/nausea, and visual symptoms are features of migraine headache. Reference: Okeson, J: Management of Temporomandibular Joint Disorders and Occlusion, 4th Edition. Mosby, 1998, p222-223.

Answer 75

Answer: C Rationale: Contralateral coronoidectomy/coronoidotomy may be necessary due to temporalis shortening/fibrosis. The requirement for contralateral coronoidectomy/coronoidotomy is established through examination of mandibular mobility after arthrotomy/excision of ankylosis. Reference: Kaban L: A protocol for the management of TMJ ankylosis. J Oral Maxillofac Surg 48:1145-1152, 1990.

Answer 76

A key technical element in the performance of modified condylotomy that differs from vertical ramus osteotomy for mandibular setback is: A. Short vertical osteotomy directed from the sigmoid notch posteriorly through the posterior border of the ramus. B. Deliberate anterior re-positioning of the proximal segment. C. Long vertical osteotomy directed from sigmoid notch to the gonial angle. D. Deliberate partial detachment of the medial pterygoid muscle from the inferior aspect of the proximal segment.

Answer 77

Answer: A Rationale: Morning stiffness is typically found with rheumatoid arthritis but not osteoarthritis. Joint space narrowing, crepitant joint noise and preauricular pain may be seen in both conditions. Reference: Silverstein K; Arthritis of the temporomandibular joint. In: Fonseca, RJ. Bays RA, Quinn PD (eds); Oral and Maxillofacial Surgery. WB Saunders, 2000, p78-81.

Answer 78

Answer: C Rationale: Katzberg, et al discovered that 25/76 (33%) asymptomatic volunteers (no joint noise, locking, or pain or tenderness) had an internal derangement in one or both joints. 79/102 (79%) symptomatic patients had an internal derangement in one or both joints. The symptomatic participants were more likely to have disc displacement without reduction. Similar data is presented by Kircos, et al. Reference: Katzberg RW, Westesson PL, Tallents RH, et al: Anatomic disorders of the TM joint disc in asymptomatic subjects. J Oral and Maxillofac Surg 54: 147, 1996 Kircos LT, Ortendahl DA, Mark AS: Magnetic resonance imaging of the disc in asymptomatic volunteers. J Oral and Maxillofac Surg 45:852, 1987

Answer 79

Answer: A Rationale: In both adult and pediatric patients TMJ pain is associated with disc displacement in 77-94% of subjects. The incidence of painful disc displacement peaks during puberty. The prevalence of asymptomatic disc displacement is 6% in a population with a median age of 11 years (Hans, et al) and 34% in a population with a median age of 16-19 years (Ribeiro, et al). The high prevalence of disc displacement in asymptomatic joints suggests that internal derangement may be congenital. However, the finding by Paesani, et al of normal disc position in 60 joint imaged in children aged 2-5 years supports an acquired etiology for internal derangement. Reference: Hans MG, Liberman J, Goldberg J, et al: A comparison of of clinical examination, history, and magnetic resonance imaging for identifying orthodontic patients with TM joint disorders. Am J Orthod Dentofac Orthop 101: 54, 1992. Ribeiro RF, Tallents RH, Katzberg RW, et al: The prevalence of disc displacement in symptomatic and asymptomatic volunteers aged 6 to 25 years. J Orofac pain 11: 37, 1997. Paesani D, Ezequiel S, Martinez A, et al: Prevalence of TM joint disk displacement in infants and young children. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 87:15,1999.

Answer 80

Answer: B Rationale: Patients in the 20-40 year age range are most likely age group to seek treatment for internal derangement. Reference: Nickerson JW, Boering, G: Natural course of osteoarthrosis as it relates to internal derangement of the TM joint. Oral Maxillofac Surg Clin North Am 1: 27, 1989

Answer 81

Answer: B Rationale: Bite disturbance is minimized with a brief (1 week –unilateral, 2-3 weeks-bilateral) period of maxillomandibular fixation followed by a period (3-4 weeks-bilateral, 5 weeks-unlateral) of training elastic use. Bite disturbance is more common in the setting of bilateral condylotomy, pre-existing malocclusion, and missing molars on the operated side. Ligation of anterior teeth can allow for dental compensation and minimize open bite malocclusion especially after bilateral condylotomy. Reference: Hall HD, Nickerson JW, McKenna SJ: Modified condylotomy for treatment of the painful temporomandibular joint with a reducing disc. J Oral Maxillofac Surg 51:133-142, 1993.

Answer 82

Answer: A Rationale: External auditory canal edema and possibly tympanic membrane edema may be explained by extravasation joint irrigant through the foramen of Huschke, a residual defect in the tympanic plate. Another potential explanation for this complication is extravasation of fluid along the ligaments within Huguire's canal within petrotympanic fissure. Reference: Tsuyama M, Kondoh T, Seto K, et al: Complications of TM joint arthroscopy: A retrospective analysis of 301 lysis and lavage procedures performed using the triangulation technique. J Oral and Maxillofac Surg. 58: 500, 2000.

Answer 83

Answer: A Rationale: Trigeminal neuralgia is characterized by paroxysmal, lacinating pain in the distribution of one or more of the divisions of the 5th nerve in a woman in the 6th or 7th decade of life. Pain of trigeminal neuralgia is usually provoked by trivial stimulation of the involved dermatome. Traumatic trigeminal neuralgia occurs in a younger population and is associated with tissue or nerve injury. Traumatic trigeminal neuralgia is characterized by continuous burning pain. Reference: Graff-Radford SB: Trigeminal neuralgia. Oral Maxillofac Surg Clinic North Am. 12:237, 2000.

Answer 84

Answer: B Rationale: The mechanism of action of the sumatriptan and other “triptans” is by inhibition of cerebral vessel and dural pain fibers. Additionally, the “triptans” are serotonin agonists are directly bind 5-HT pre-synaptic receptors causing vasoconstriction. Thus, “triptans” modulate vascular headache pain by direct inhibition of dural/cerebral vascular pain fibers and by antagonism of cerebral vasodilation. Reference: Dym H: Diagnosis and treatment of headache. Oral Maxillofac Surg Clin North Am. 12:248, 2000.

Answer 85

Answer: C Rationale: Wilkes stage IV (intermediate late stage) internal derangement is defined as complete disc displacement with hard-tissue degenerative remodeling changes and clinical chronicity. Interincisal opening is usually greater than 30mm in late-stage disease. Option A describes early Wilkes stage III (intermediate stage) internal derangement. Option B suggests a component of muscle guarding/splinting that does not define a particular Wilkes stage. Maximum opening usually exceeds 25 mm in stage IV internal derangement as a result of progressive disc deformity. Option D describes the controversial concept of avascular necrosis and is not associated with a particular Wilkes stage. Reference: Wilkes CH: Surgical treatment of internal derangement of the temporomandibular joint: A long-term study. Arch Otolaryngol Head Neck Surg 117:64, 1991

Answer 86

Answer: B Rationale: Option A describes chronic TMJ dislocation. Option C describes Wilkes stage I (early stage) internal derangement. Option D describes Wilkes stage IV (intermediate late stage) internal derangement. Reference: Wilkes CH: Surgical treatment of internal derangement of the temporomandibular joint: A long-term study. Arch Otolaryngol Head Neck Surg 117:64, 1991.

Answer 87

Answer: D Rationale: Modified condylotomy is capable of effecting disc reduction in 80% of joints with anterior disc displacement with reduction (Wilkes stage II) or with discs that have recently progressed to non-reducing disc status (Wilkes early stage III). Reference: Werther JR, Hall HD, Gibbs SJ: Disk position before and after modified condylotomy in 80 symptomatic joints. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 79:668, 1995.

Answer 88

Answer: C Rationale: Sleep bruxism shares many features with untreated obstructive sleep apnea. In an evaluation of over 13,000 subjects sleep bruxism was associated with anxiety disorders, caffeine consumption but is was not associated with periodic limb movement or nasal CPAP use. Reference: Ohayon MM, Li KK, Guilleminault C: Risk factors for sleep bruxism in the general population. Chest 119:53, 2001.

Answer 89

Answer: C Rationale: Elevated plasma C-reactive protein is associated with progression of TM joint bone loss. The next most common laboratory evaluation for RA is rheumatoid factor (RF) which is positive in 70-80% of patients. RF titers greater than 1:1280 are associated with severe and progressive disease. A positive anti-nuclear antibody (ANA) titer will be detected in 15-20% with rheumatoid arthritis. Radiographic TM joint involvement is seen in approximately 40% with rheumatoid arthritis. TM joint symptoms occur in approximately 30% with rheumatoid arthritis. The most common CT radiographic finding is decreased joint space. Reference: BayerN, Kara SA, Koc MC, et al: Temporomandibular joint involvement in rheumatoid arthritis: A radiological and clinical study. Cranio 20:105, 2002. Nordahl S, Alstergren P, Kopp S: Radiographic signs of bone destruction in the arthritic temporomandibular joint with special Reference to markers of disease activity: A longitudinal study. Rheumatol 40:691, 2001.

Answer 90

Answer: A Rationale: The concept of minimizing TM joint stress refers to measures to avoid counterclockwise mandibular rotation and ramus lengthening at the time of mandibular advancement. The type of fixation (rigid vs. semi-rigid vs. non-rigid) has no proven impact on joint problems after orthognathic surgery. Simultaneous arthrotomy and ramus osteotomies have not been demonstrated to control TM joint stress after orthognathic surgery. Reference: Wolford LM, Reiche-Fischel O, Pushkar, M: Changes in temporomandibular joint dysfunction after orthognathic surgery. J Oral Maxillofac Surg 61:655, 2003. Cottrell DA: Discussion Re: Wolford LM, Reiche-Fischel O, Pushkar, M: Changes in temporomandibular joint dysfunction after orthognathic surgery. J Oral Maxillofac Surg 61:661, 2003.

Answer 91

Answer: tmpanic part of the temporal bone. B Rationale: The roof of the fossa is formed primarily by the squamous portion of the temporal bone. It is separated from the tympanic plate by the squamotympanic fissure. The medial 2/3rds the roof of the fossa is inferior to the middle cranial fossa. The petrous portion of the temporal bone is pyramidal, wedged in at the base of the skull between the sphenoid and occipital bones and does not form part of the fossa. Reference: Spagnoli DB: Anatomy of the temporomandibular joint. Oral Maxillofacial Surgery Knowledge Update. American Association of Oral Maxillofacial Surgeons, Chicago, 1994 1:17.

Answer 92

Answer: C Rationale: l-Kayat and Bramley performed 56 cadaveric dissections and measured the distance from the anterior concavity of the external auditory canal to the point where the temporal branch of the facial nerve crosses the zygomatic arch. The range was found to 0.8-3-5cm with a mean distance of 20 mm. Reference: Al-Kayat A, Bramley P: A modified pre-auricular approach to the temporomandibular joint and malar arch. Br J Oral Surg 17:91-103, 1979.

Answer 93

Answer: A Rationale: Psoriatic arthritis affects men more that women. It often presents as a rheumatoid-like, erosive polyarthritis affecting approximately 6% of the patients with psoriasis. Laboratory studies are usually negative for RF and ANA, and there are no rheumatoid nodules. TMJ involvement is characterized by episodic unilateral arthritis with restricted opening. Timing of exacerbation of TMJ and skin symptoms is often coincident. Reference: Hoffman KD: Differential diagnosis and characteristics of TMJ disease and disorders. Oral Maxillofacial Surgery Knowledge Update, American Association of Oral and Maxillofacial Surgeons, Chicago, 1994 1:51.

Answer 94

Answer: C Rationale: Various modalities have been employed to decrease heterotopic bone formation after surgical treatment of TM joint ankylosis. Bisphosphonates must be taken over a prolonged period of time to limit heterotopic bone formation. Low dose radiation therapy administered in the first few days following arthrotomy can also limit heterotopic bone deposition. Systemic corticosteroids have no role in limiting heterotopic ossification. Aggressive, passive range of motion exercises may actually stimulate heterotopic bone formation from muscle trauma. Reference: Stanton DC, Stewart JCB: Tumors of the temporomandibular joint. In: Fonseca RJ, Bays RA, Quinn PD (eds): Oral and Maxillofacial Surgery, Vol 7, WB Saunders, Philadelphia, 2000, p377.

Answer 95

Answer: D Rationale: The Christiansen total TM joint prothesis fossa element is composed of cobalt-chromium alloy. Both pre- cured polymethylmethacrylate and cobalt-chromium condylar elements have been used with this system however the “universal” condylar prosthesis is composed of a polymethylmethacrylate head and cobalt- chromium ramus element. Though a patient-specific prosthesis can be fabricated using CAD-CAM technology, stock elements are available. Reference: Gerard DA, Hudson JW: The Christiansen TMJ prosthesis system. Oral and Maxillofac Clin North Am. 12: 61, 2000.

Answer 96

Answer: D Rationale: The TM joint is most often involved in the polyarticular subtype of juvenile rheumatoid arthritis (JRA). The clinical features of JRA of the TM joint include pain, joint tenderness, crepitant sounds, stiffness/decreased range of motion. Radiographic changes consist of condylar erosion, ramus shortening and an accentuated antegonial notch. The mandible appears micrognathic with clockwise rotation and the development of a Class II open bite malocclusion. Reference: Barriga B, Lewis TM, Law DB: An investigation of the dental occlusion in children with Juvenile Rheumatoid Arthritis. Angle Orthod 44: 329, 1967 Abubaker OA: Differential diagnosis of arthritis of the TM joint. Oral Maxillofac Clin North Am 7:1, 1995

Answer 97

Answer: B Rationale: Botulinum toxins are a group of eight toxins elaborated by Clostridium botulinum, a gram positive anaerobic organism. The primary effect of botulinum toxin is receptor-mediated endocytosis of the toxin in the area of neuromuscular synapse with selective proteolysis of the vesicular protein SNAP (synaptonal associated protein). This event prevents the release of acetylcholine into the neuromuscular junction. Reference: von Linden JJ, Neiderhagen B, Berge S: Type –A botulinum toxin in the tre.

Answer 98

Answer: D Rationale: Electrophysiologic testing (EPT) is the most reliable prognostic tool for the assessment of post-traumatic nerve recovery. The utility of EPT is in its ability to differentiate injuries that will recover from injuries possibly requiring surgical intervention. EPT has limited applicability in the first three days post-injury because Wallerian degeneration is incomplete and false positive results are common. Proper timing of EPT should also take into account the 2-3 weeks necessary for denervational muscle changes following nerve injury. Electroneurography and electromyography are the two EPT modalities used to study facial nerve function. Electroneurography is the most accurate method of predicting of nerve recovery. When the response to electroneurography is less than 10% of the normal side a poor outcome is expected. Conversely, if the response to electroneurography remains greater than 10% of the response on the unaffected side up to three weeks post-injury the prognosis for spontaneous recovery is favorable. Electroneurography should first be performed after Wallerian degeneration is complete, approximately three days post-injury. Electromyography estimates the extent of muscle denervation and the timing and completion of functional recovery. Therefore electromyography is delayed for 2-3 weeks until denervation changes occur. Electromyography is most useful in the period 2-3 weeks post-injury to 15 weeks post-injury. Early EPT is widely recommended to assess the magnitude of nerve injury and determine the role for early nerve repair. Reference: Davis RE, Telischi FF: Traumatic Facial nerve injuries, J CranioMaxillofac Trauma 1:30, 1995.

Answer 99

Answer: C Rationale: The Lorenz total TM joint prosthesis is composed of cobalt-chromium ramus component. The host-bone surface of the ramus component is roughened with a titanium plasma coating. The fossa element is made of ultra-high molecular weight polyethylene that is stabilized with screws. Polymethylmethacrylate bone cement may also be used to fill voids but the cement is not designed as a load bearing medium. Reference: Quinn PD: Lorenz prosthesis. Oral Maxillofac Clin North Am 12: 93, 2000.

Answer 100

Answer: C Rationale: The temporal branch of the facial nerve is situated between the temporoparietal fascia and the temporalis fascia on the deep surface of the temporoparietal fascia. Reference: Ellis E and Zide MF: Surgical Approaches to the Facial Skeleton. Williams and Wilkins, 1995, p167

Answer 101

Answer: B Rationale: The auriculotemporal branch of the 3rd division of the 5th cranial nerve provides sensation to the preauricular skin. Reference: Holmlund AB: Arthroscopy. In: Fonseca RJ, Bays RA, Quinn PD (eds): Oral and Maxillofacial Surgery. WB Saunders, 2000, p268

Answer 102

Answer: C Rationale: Osteoarthritis (OA) is a chronic non-inflammatory condition that effects the articular cartilage of synovial joints. Unlike rheumatoid arthritis the synovium is only involve secondarily. Osteoarthritis is the most common disease affecting the TM joint. In contrast to rheumatoid arthritis, when osteoarthritis involves the hands the DIP joint is most often involved. Unlike rheumatoid arthritis (RA), morning stiffness is not characteristic of OA but when present generally lasts less than 30 minutes. Radiographic changes in OA consist of subchondral sclerosis, condylar flattening, lipping and erosion. Laboratory findings in OA are unremarkable where as in RA the erythrocyte sedimentation rate is usually significantly elevated and the latex agglutination test is positive. Gouty arthritis of the TMJ is more likely to be seen in late stage disease. The initial joint most frequently affected in gout is the MTP of the great toe. Giant call arteritis does not affect the TM joint and is associated with an elevated sedimentation rate. Reference: Silverstein K: Arthritis of the temporomandibular joint. In: Fonseca RJ, Bays RA, Quinn PD (eds): Oral and Maxillofacial Surgery. WB Saunders, 2000, p75-91.

Answer 103

Answer: B Rationale: Frey syndrome, or “gustatory sweating” is a relatively common complication of parotidectomy but uncommon following TM joint arthrotomy. It is believed to be caused by aberrant regeneration of post- ganglionic parasympathetic parotid secretomotor fibers with severed post-ganglionic sympathetic fibers innervating facial sweat glands. Reference: Dolwick MF, Armstrong JW: Complications of temporomandibular joint surgery. In: Kaban L, Perrott d, Pogrel T (eds): Complications in Oral and Maxillofacial Surgery. WB Saunders, Philadelphia, 1997, p 93.

Answer 104

Answer C Rationale: In the setting of normal TM joints, bruxism and muscular pain the most appropriate treatment should be initially directed towards the control of bruxism. Of the options listed, only splint therapy has a potentially beneficial role in the management of bruxism. In this clinical scenario there is no indication for initia irreversible treatments such as occlusal equilibration, arthroscopy, etc. Reference: Laskin DM: Diagnosis and etiology of myofascial pain and dysfunction in medical management of temporomandibular disorders. Oral Maxillofac Surg Clin North Am. 7:77, 1995.

Answer 105

Answer: B Rationale: Sympathetic innervation controls sweating and vascular smooth muscle tone. Postganglionic parasympathetic fibers from the otic ganglion are severed in this condition. Misdirected regeneration of parasympathetic fibers to sweat gland sympathetic fibers and receptors accounts for this condition. Reference: Marx RE, Stern D: Oral & Maxillofacial Pathology: A Rationale for Diagnosis and Treatment. Quintessence Publishing Co, Inc, Chicago, 2003, pp. 28-29.

Answer 106

Answer: C Rationale: The action of the superior head of the lateral pterygoid muscle (SHLP) is controversial. However, sophisticated analysis of motor unit activity has demonstrated muscle unit heterogeneity in the SHLP. Therefore depending on the medial-lateral location of muscle units increased SHLP may occur with closing, opening, protrusion, and contralateral jaw movements. Reference: Planachet I, Whittle T, Wanigaratne K, et al: Functional heterogeneity in the superior head of the human lateral pterygoid. J Dent Res 82: 106, 2003

Answer 107

Answer: B Rationale: As many as seven types of disc displacement have been described in MR imaging of symptomatic TM joints. Werther, et al demonstrated that 74% of disc displacements fall into the two most common groups, anterior (45%) and medial rotary ((29%). Of the options listed lateral disc displacement is the least common, occurring in 2.5% of symptomatic joints. Similarly, Simmons found no case of lateral disc displacement in 58 symptomatic joints imaged with MRI. Reference: Simmons HC, Gibbs SJ: Initial TMJ disk recapture with anterior repositioning appliances and relation to dental history. J Craniomandib Prac 15:28, 1997. Werther JR, Hall HD, Gibbs SJ: Disk position before and after modified condylotomy in 80 symptomatic TM joints. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 79: 668, 1995.

Answer 108

Answer C Rationale: The arthrokinetic reflex is an orthopedic concept that states that internal derangement can cause muscle spasm in the muscles supporting that joint and that when the internal derangement is resolved the muscles cease to spasm. For example, in the setting of disc displacement with reduction, increased EMG activity of the temporalis and masseter muscles occurs when the condyle slides over the posterior band of the disc during closure. Muscle activity decreases when the disc position is normalized with mouth opening. Reference: Isberg A, Widmalm SE, Ivarsson R: Clinical, radiographic and electromyographic study of patients with internal derangements of the temporomandibular joint. Am J Orthodont 88:453, 1985.

Answer 109

Answer: D Rationale: Though MR imaging and doppler may depict an internal derangement and suggest a source for pain, internal derangement may occur coincidentally in the setting of complex facial pain not originating in the TM joint. Although a detailed history can often suggest the source of pain, diagnostic nerve blocks can be used to systematically localize a source of pain. Diagnostic anesthetic block of the auriculotemporal nerve largely eliminates the temporomandibular joint from a complex facial pain presentation and can facilitate localization of a pain source. Reference: Pertes RA, Gross SG. Clinical Management of Temporomandibular Disorders and Orofacial Pain. Quintessence Publishing Co., Inc. 1995, p156.

Answer 110

Answer: B Rationale: Temporomandibular joint arthrocentesis includes lavage of the upper joint space, hydraulic distension, manipulation, and instillation of a corticosteroid. Arthrocentesis is indicated for acute or chronic limitation of motion due to anterior disc displacement without reduction and hypomobility due to restriction of condylar translation in the superior joint space. Reference: Murakami KI, Matsuki M, Iizuka T, OnoT: Recapturing the persistent anteriorly displaced disk by mandibular manipulation after pumping and hydraulic pressure to the upper joint cavity of the temporomandibular joint. J Craniomandib Prac. 5:17, 1987. Frost DE, Kendell BD: The use of arthrocentesis for treatment of TM joint disorders. J Oral Maxillofac Surg 57: 583, 1999.

Answer 111

Answer: B Rationale: The important vascular structure medial and anterior to the glenoid fossa is the middle meningeal artery (MMA). The mean anterior-posterior distance of the MMA from a line tangent to the maximum height of the glenoid fossa is 2.4mm. The distance of the internal carotid artery and internal jugular vein from the same landmark is 6.5 and 8.7mm respectively. Though injury to the MMA is uncommon, catastrophic bleeding may occur if this structure is violated during surgery medial to the TM joint. Reference: Talebzadeh N, Rosenstein TP, Pogrel MA: Anatomy of the structures medial to the TM joint. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 88: 674, 1999.

Answer 112

Answer: B Rationale: The incidence of melanoma continues to grow in the white population with the highest rate being in northern Australia. Of this population, melanoma is seen most commonly in people with red or blond hair, fair skin, large numbers of freckles, and the potential to burn easily when in the sun. The superficial spreading melanoma is the most common variety being seen almost twice as often as the nodular type. The acral lentiginous melanoma as the name denotes is a tumor of the palmar, plantar, and subbing skin. Reference: Regal, DS, Friedman, RJ, Kip, AW. The incidence of malignant melanoma in the United States as we approach the 21st century. J Am Acad Dermatol 1996; 34:839-847. Clark, WH, Elder, DE, van Horn, M. The biologic forms of malignant melanoma. Hum Pathol 1986; 17:443-450.

Answer 113

Answer C Rationale: Even though histologically very similar to Bowen's Disease, Erythroplasia of Queyrat is a dysplastic lesion of the penis in uncircumcised males. It usually arises on the inner surface of the prepuce. Actinic keratosis, Bowen's disease of skin (carcinoma in situ) and the morpheaform (sclerosing) variant of basal cell carcinoma are all well accepted examples of sun induced skin disease. Reference: Hodge, SJ, Turner, JE. Histopathologic concepts of intraepithelial epithelioma. Int J Dermatol 1986; 25:372-375. Graham, JH, Helwig, EB. Erythroplasia of Queyrat. A clinicopathologic and histochemical study. Cancer 1972; 32:1396-1414.

Answer 114

Answer: C Rationale: 80% of BCC's are in the head and neck region. The BCC as well as the squamous cell carcinoma are both seen in cases of Xeroderma Pigmentosum. The most common variant of the BCC is the solid type, which represents approximately 70% of all cases. Reference: Miller, DL, Weinstock, MA. Nonmelanoma skin cancer in the United States Incidence. J Am Acad Dermatol 1994; 30:774-778. Miller, SJ. Biology of the basal cell carcinoma. J Am Acad Dermatol 1991, 24:1-13.

Answer 115

Answer: A Rationale: Inheritance is autosomal dominant with complete penetrance and variable expressability. The basal cell carcinomas seen in Basal Cell Nevus Syndrome are typically seen on sun-exposed and non sun-exposed skin, they occur at an earlier age than the classic basal cell carcinoma, and rib abnormalities (bifid rib) are seen in about 60% of patients with this syndrome. Reference: Gorlin RJ, Goltz RW. Multiple nevoid basal-cell epithelioma, jaw cysts and bifid rib syndromes. N Engl J Med 1960; 262:908-912

Answer 116

Answer: A Rationale: The classic presentation of a KA is a solitary lesion of the facial sun-exposed skin in an older male. It is typically a fast growing lesion, reaching its maximal size within approximately 6 weeks. This is a feature that helps to distinguish it from squamous cell carcinoma of the skin. Reference: Schartz RA. Keratoacanthoma. J Am Acad Dermatol 1994; 30:1-19. Ahmed, AR. Multiple keratoacanthoma. Int J Dermatol 1980; 19:96-499.

Answer 117

Answer: C Rationale: Parakeratin is the defining histologic feature of the OKC. Orthokeratin is found in other odontogenic cysts particularly the dentigerous cyst. Daughter cysts are not an exclusive feature of OKC's either although their presence contributes to the high recurrence rate potential. Rete peg formation is not a histological feature of the OKC due to such a thin epithelial lining of 6 – 10 cells. Reference: Oral Maxillofacial Surg Clin N Am 15 (2003) 325-333.

Answer 118

Answer: D Rationale: The most prominent and unique characteristic of the Gorlin cyst (COC) is “ghost cell” keratinization. These cells are anuclear and retain the cell outline. There is a dystrophic mineralization process that occurs here. Cuboidal to columnar epithelial pattern does exist here but is not the unique differentiating histologic feature. Daughter cysts are more prominent in OKC Reference: Regezi, JA, Sciubba, JJ Oral Pathology Clinical Pathologic Correlation 3rd Ed. W.B. Saunders Co. 1999 pp.304-305.

Answer 119

Answer: C Rationale: The AOT can be either a mixed radio-opaque/ radiolucent or a radiolucent lesion. The radiographic characteristic of the AOT vs. dentigerous cyst is the complete encompassing of the involved tooth by the cyst lining in the AOT vs. CEJ attachment in the dentigerous cyst. Age and sex distribution patterns are not defining characteristics in differentiating the two. AOT is not confined to the anterior maxilla. Reference: Regezi, JA Sciubba, JJ, Oral Pathology Clinical and Pathologic Correlations 3rd Ed. W.B. Saunders Co. 1999; 291-295, 339.

Answer 120

Answer: C Rationale: Although all of the above are plausible sswers, in the basal cell nevus syndrome the biologic behavior of the OKC more closely resembles a benign neoplasm. According to Toller, the aggressive nature of the OKC in this syndrome relates to remnants of the dental lamina as precursors to new cyst formation. This characteristically resembles odontogenic tumors. Reference: Shear, M. Oral Maxillofacial Surg Clin N Am 15 (2003) 335-345.

Answer 121

Answer: B Rationale: "Mandibular osteosarcomas are more frequent than those in the maxilla (60% vs 40%)." In general terms, osteosarcoma of the facial skeleton occurs in a younger age group, with declining frequency in older patients. Reference: Marx RA, Stern D. Oral and Maxillofacial Pathology A Rationale for Diagnosis and Treatment; Quintessence, Chicago 2003, 799.

Answer 122

Answer: A Rationale: Osteosarcomas of the jaws are ideally treated with initial (neoadjuvant) chemotherapy of about five cycles, followed by surgery, which is followed by two or three additional doses of chemotherapy (adjuvant). Radical neck dissection has no role to play in the management of osteosarcoma, as lymphatic dissemination is almost non-existent, while hematogenous dissemination is the rule. Some osteosarcomas of the facial skeleton may be treated by ablative surgery alone, however, this is not considered the best treatment. Reference: Curran AE, Damm, D, Drummond, JF Pathologically Significant Pericoronal Lesions in Adults Histopathologic evaluation. J Oral Maxillofac. Surg 60 6l3-617, 2002.

Answer 123

D Rationale: For rhabdomyosarcoma, chemotherapy added to surgery and radiation therapy has been reported to improve 5-year survival compared with that seen with surgery and/or radiation therapy alone. Reference: Kramer AM, The role of chemotherapy in head and neck malignancy" in Malignant Tumors of the Maxillofacial Region, Pogrel MA ed. OMFS Clin NA Vol 5, No. 2, May 93, 313.

Answer 124

C Rationale: Treatment (of LG mucoepidermoid CA) is normally mandibular resection; postoperative radiation therapy is often not required, particularly for low-grade tumors, making mandibular reconstruction a simpler proposition. Reference: Pogrel MA, The diagnosis and management of salivary gland tumors" in Malignant Tumors of the Maxillofacial Region, Pogrel MA ed. OMFS Clin NA Vol 5, No. 2, May 93, 325

Answer 125

B Rationale: Osteoradionecrosis can be characterized as impaired wound healing due to the nature of radiation induced vasculitis and subsequent radiation fibrosis which severely compromises or even eliminates the microvasculature of the periosteum as well as endosteal tissue vascular channels while challenging and disabling the overlying integumental vascular plexus as well. There is a certain amount of intranuclear destruction that does occur in all cells present in the radiated field rendering some cell death through DNA disruption; however, the majority of injury occurs to the endothelial vascular lining via superoxide radicals. Reference: Schwartz HC, Kagan AR Osteoradionecrosis of the Mandible. Am J Clin Oncol 25(2) 168-171, 2002.

Answer 126

B Rationale: Calcified and soft tissue radiation injury in general is caused by superoxide radical generation as the enzymatic protective pathways against superoxides are by and large severely compromised by the sustained radiation exposure. This directly affects the calcified tissue by severely limiting its vascular metabolic support. Reference: Heimbach RD Radiation effect on tissue. In Davis JC, Hunt TD (eds) Problem Wounds The Role of Oxygen. New York, Elsevier Science 1988, p 53.

Answer 127

Answer: B Rationale: Tooth removal induced radiation necrosis is more likely to occur six to twelve months post treatment as radiation vasculitis and fibrosis are a progressive entity from radiation therapy induction to the completion and progressing factor in a compounding fashion. Initially, there is hyperemia of the insulted tissues with the vascularity remaining intact to the greater degree but with slow progression towards cell death and fibrosis over time which enhances the opportunity for other tissue necrosis such as bone. Reference: Hudson JW Osteomyelitis and Osteoradionecrosis. In Fonseca RJ (ed) Oral and Maxillofacial Surgery Surgical Pathology. Philadelphia, WB Saunders Company, 2000, pg 484-495.

Answer 128

Answer: A Rationale: Brodie's abscess is commonly associated with infection of a bone. It was identified anatomically and classically many years ago in orthopedic literature relative to axial or long bone osteomyelitis where there appeared to be a very well organized infectious process that walled itself off from the host immune response and any other therapeutic modalities save for surgical intervention. This same phenomenon has been appreciated in the mandible as it is commonly seen with the inflammatory response of the periosteum and the walling effect that can occur in terms of limiting the wound from a vascular penetrance. Reference: Hudson JW Osteomyelitis of the jaws A 50-year perspective. J Oral Maxillofac Surg 1993; 51:1294.

Answer 129

Answer: C Rationale: The presence of gross purulence in an osteomyelitic wound characterizes as infection as immunologically responsive due to the actual composition of the purulence being made up by white blood cells or granulocytes, phagocytizing foreign body under the chemotactic influence of an inflammatory/immune cascade. The presence of pus in an osteomyelitic wound will not permit the distinction between acute and chronic osteomyelitis. Reference: Cierny G, Mader TJ, Pennick JJ A clinical staging system for osteomyelitis. Contemp Orthop 1985; 10:17.

Answer 130

Answer: B Rationale: It is generally recommended that a segmental defect of the mandible be reconstructed with 1 cc of corticocancellous bone per every 1 mm of defect. Adding 10% to this harvested volume will ensure the procurement of sufficient bone. As such, a 7.5 cm defect, or 75 mm, would be expected to require 75-85 cc's of bone. Reference: Marx RE, Morales MJ Morbidity from bone harvest in major jaw reconstruction A randomized trial comparing the lateral anterior and posterior approaches to the ilium. J Oral Maxillofac Surg 48 196-203, 1988.

Answer 131

Answer: B Rationale: The harvest of 75-85 cc's is predictably possible only from the posterior ilium. The clavicle is not generally described as a donor site for mandibular reconstruction. The anterior ilium is expected to yield approximately 30 – 40 ml of cancellous bone, while the tibia would be expected to yield approximately 15 – 20 ml. Therefore, a 7.5 cm defect of the mandible can only be predictably reconstructed with a harvest of bone from the posterior ilium. Reference: Stevens MR Bone harvesting techniques. Oral and Maxillofacial Surgery Knowledge Update 1 RCN 19- 34, 1994.

Answer 132

Answer: B Rationale: The time honored protocol for the administration of HBO to an irradiated patient in preparation for mandibular reconstruction is 20 preoperative treatments followed by surgery and 10 postoperative treatments. This protocol assumes that a diagnosis of osteoradionecrosis of the mandible has not been met. When such a diagnosis is met, the patient receives 30 treatments of HBO initially followed by re- evaluation. Reference: Quereshy FA, Powers MP Reconstruction of the maxillofacial cancer patient. In Fonseca RJ (ed) Oral and Maxillofacial Surgery, Volume 7, Reconstructive and Implant Surgery, Chapter 15, Philadelphia, WB Saunders Co., 361-444, 2000.

Answer 133

Answer: D Rationale: An isotonic solution is crucial to avoid rupture of bone cells. The only isotonic solution among the answers is normal saline. D5W and sterile water are hypotonic, while hypertonic saline is hypertonic. Hypotonic and hypertonic solutions do not support the physiology of harvested bone. Reference: Marx RE, Snyder RM, Kline SN Cellular survival of human marrow during placement of marrow- cancellous bone grafts. J Oral Surg 37 712-718, 1979.

Answer 134

Answer: D Rationale: Harvested bone cells show about a 95% viability up to four hours at OR temperatures. Reference: Marx RE, Snyder RM, Kline SN Cellular survival of human marrow during placement of marrow- cancellous bone grafts. J Oral Surg 37 712-718, 1979.

Answer 135

C Rationale: Separation of the oral mucosa from the nasal-antral mucosa is very important. Saliva is kept out of the nasal cavity. Speech and function are usually improved by this separation. The quality of the mucosa is different as well, with an obturator better adapted to the oral mucosa. Reference: Fonseca and Davis, Reconstructive Preprosthetic Oral and Maxillofacial Surgery, 2nd Ed. pp. 1116- 1118

Answer 136

Answer: A Rationale: The primary role of the fibula is stabilization of the knee and ankle joint. Five to six centimeters of fibula should be left proximally and distally for this reason to prevent instability of these joints. The peroneal nerve also limits the proximal dissection, but that is not a choice. The take-off of the peroneal artery from the posterior tibial artery limits the pedicle length, but not the bone length. Likewise, the venae comitantes can be harvested along the length of the arterial pedicle, but does not limit the bone stock. Although controversial, some surgeons do feel the entire proximal fibula can be harvested, including the portion that contributes to the knee, however, the distal portion must always be preserved for ankle stability. Therefore, A is the best choice. Reference: Urken ML, et al. Atlas of regional and free flaps for head and neck reconstruction. Raven Press 1995.

Answer 137

Answer: B Rationale: The lateral antebrachial cutaneous nerve provides sensation to the territory harvested most commonly with the RFFF. It can be reconstructed to the lingual nerve in attempt to provide a sensate flap. Harvest of the ulnar nerve would lead to excessive morbidity as it is a motor and sensory nerve. It would affect the ability to flex and abduct the wrist and movement of the thumb. Fine movements of the fingers would also be affected. The radial nerve is specifically protected in the harvest of the radial forearm flap, and indeed the subfascial plane of dissection must be broken to preserve this nerve. Finally, the medial cutaneous antebrachial nerve can be harvested, but it does not supply the territory typically harvested. Reference: Schustermann MA. Microsurgical reconstruction of the cancer patient. Lippincott-Raven 1997.

Answer 138

Answer: D Rationale: The peroneal artery and its associated venae commitans make up the vascular pedicle to the vascularized fibula flap. The popliteal artery divides into the anterior tibial and posterior tibial arteries. The posterior tibial then gives off the peroneal artery, which supplies the vascular territory of the fibula flap. Harvest of the popliteal artery would leave the lower leg without a blood supply. The posterior tibial artery is preserved to maintain vascular blood supply to the lower leg. Reference: Urken ML, et al. Atlas of regional and free flaps for head and neck reconstruction. Raven Press 1995.

Answer 139

B Rationale: Sacrifice of the radial artery relies on an intact communication between the superficial and deep palmer arches. This is typically confirmed pre-operatively by an Allen's test. The technique is as follows: 1. Elevate the patient's hands above heart 2. Occlude radial and ulnar arteries 3. Have the patient open and close fist several times 4. Lower the hand below heart 5. Release ulnar artery and time blood flow return to hand 6. Repeat with radial artery If there is no communication between the superficial and deep palmar arches, sacrifice of the radial artery will result in vascular compromise to the thumb. The palm, middle finger and 5th digit are supplied by the ulnar artery. Reference: Urken ML, et al. Atlas of regional and free flaps for head and neck reconstruction. Raven Press 1995.

Answer 140

Answer: A Rationale: Sjogren's syndrome is an autoimmune disease that causes a lymphocyte-mediated destruction of exocrine glands. This results in a decrease in glandular secretion of the salivary glands (xerostomia) and the lacrimal glands (xerophthalmia). Reference: Marx RE Incisional parotid biopsy for diagnosis of systemic disease. Oral and Maxillofac Surg Clin North Am 7:505-517, 1995

Answer 141

Answer: D Rationale: Sialosis is a generalized hypertrophy of the individual acinar cells that results in bilateral enlargement of the parotid gland. It is not associated with an immune disorder or neoplastic process. The parotid enlargement is usually secondary to nutritional changes brought about by alcoholism or bulimia. An incisional parotid biopsy is indicated to rule out Sjogren's disease, sarcoidosis and lymphoma. Reference: Parret J, Cros P, Dumas P, et al Sialosis hypertrophiques. Rev Stomatol Chir Maxillofac 80:329-333, 1979. Marx RE Incisional parotid biopsy for diagnosis of systemic disease. Oral and Maxillofac Surg Clin North Am 7:505-517, 1995.

Answer 142

Answer: A Rationale: Sarcoidosis is a systemic disease characterized by infiltration of tissues with sarcoid granulomas. In Heerfordt's syndrome, clinical enlargement of the parotid and lacrimal gland (sarcoid infiltrate) is seen together with retinal damage. Chronic sarcoidosis has a 6:1 black to white patient ratio and a slight female predilection. Anorexia, lethargy and pulmonary involvement with hilar adenopathy are a common clinical finding. Reference: Thomas PD, Hunninghake GW Current concepts of the pathogenesis of sarcoidosis. Am Rev Respir Dis 135:747-754, 1987. Marx RE Incisional parotid biopsy for diagnosis of systemic disease. Oral and Maxillofac Surg Clin North Am 7:505-517, 1995

Answer 143

Answer: C Rationale: Benign lymphoepithelial lesions typically present as a unilateral or bilateral parotid gland swelling resulting from a diffuse benign infiltration of lymphoid cells. It is believed that these lesions develop as a result of an immunologic abnormality. These lesions can also be seen in association with Sjogren's syndrome. There is no specific treatment for these lesions other than follow-up and observation given the small potential for malignant transformation and its relationship with Sjogren's syndrome. Reference: Regezi JA, Sciubba JJ. Salivary gland diseases. In Oral Pathology: Clinical Pathologic Correlations. Philadelphia, W.B. Saunders, 1989, pp 243-245.

Answer 144

Answer: C Rationale: Karapandzic flaps are excellent single stage closures of moderately sized defects of the lower lips, especially in homebound patients and patients with a natural dentition. This flap transfers vascularized tissue to close lower lip defects up to 60% of its length. The result will be upper and lower lips unequal in size, and with a slightly retruded lower lip relative to the upper lip. Reference: Lip Reconstruction by M. Zide and J. Dean in Maxillofacial Surgery by Booth, Schendel and Hausamen, Churchill-Livingstone, Edinburgh 1999, ch 45.

Answer 145

Answer: B Rationale: Sentinel lymph node biopsy is indicated in the assessment of cervical node involvement in intermediate depth melanomas. Reference: Wagner J, Gordon MS, Chuang T, and Coleman JJ. Current therapy of cutaneous melanoma. PRS April 2000, p1774.

Answer 146

Answer: A Rationale: An Abbe flap is a local pedicled axial pattern flap for upper and lower lip reconstruction. It is ideally used for defects greater than 25% of upper lip loss and approximately 33% of lower lip loss. The pedicle is divided at about 2-3 weeks. Reference: Zide MF and Fuselier C The partial thickness cross-lip flap for correction of post-oncologic surgical defects. JOMS 59 1147, 2001.

Answer 147

Answer: B Rationale: The rhomboid flap is a transpositional flap. As such, the pivot point, where the greatest degree of tension exists, must move in extensible lines. This flap will not place all scars in resting skin tension lines, and distortion of adjacent tissues will occur. Reference: Calhoun KH, Seikaly H, Quinn FB. Teaching paradigm for decision making in facial skin defect reconstructions Arch Otol Vol 124, Jan 1998.

Answer 148

Answer: A Rationale: Direct immunofluorescence is a useful diagnostic tool to confirm the histologic features of these mucous membrane and dermal diseases. In pemphigus vulgaris, deposition of immunoglobulin is along the plasma membranes of epidermal keratinocytes in a fish-net-like pattern (as the enclosed slide shows). Whereas in bullous pemphigoid the immunoglobulin and complement deposits are linear at the basement membrane (by EM at the level of lamina lucida). In dermatitis herpetiformis (Duhring Disease) the immunoglobin deposits are the IgA subtype and are selectively localized in the tips of dermal papillae. Lupus erythematosus is not a bullous disease but is a localized cutaneous form of systemic lupus erythematosis. Direct immunochemistry is characteristic of granular deposits of immunoglobulin and complement at the dermoepidermal junction. Reference: Murphy, C and Mihm, M. The skin. Chapter 27. In Cotran, R., et al (eds.) Robbins Pathologic Bases of Disease, 6th ed., Figure 27-35, W. B. Saunders, Philadelphia, 1999, pp. 1170-1213.

Answer 149

Answer: B Rationale: A sub-basilar split is noted, thereby supporting the diagnosis of pemphigoid. Pemphigus would be expected to have a suprabasilar split, and squamous cell carcinoma and lichen planus do not typically exhibit a sub-basilar split. Reference: Neville BW, Damm DD, Allen CM, Bouquot JE (eds) Oral and Maxillofacial Pathology, 2nd Edition, Chapter 16, Dermatologic Diseases, Philadelphia, WB Saunders Co., 672, 2002.

Answer 150

Answer: B Rationale: The pathologic section clearly demonstrates an immunofluorscent pattern. The basement membrane lights up, supporting a diagnosis of pemphigoid. Since the patient's tissue is submitted, the test is direct immunofluorescence by definition. Indirect immunofluorescence involves submitting the patient's blood for antibody assay. In situ hybridization and polymerase chain reaction with Western Blot have no role in the diagnosis of vesciculobullous disease of the oral cavity. Reference: Regezi JA, Scuibba JJ, Jordan RCK (eds) Oral Pathology: Clinical Pathologic Correlations, 4th Edition, Chapter 1, Vesiculobullous Diseases, St. Louis, Elsevier Science, 14, 2003.

Answer 151

Answer: A Rationale: The classic findings of giant cell lesion are noted in the histomicrograph. These include dilated capillaries, the presence of giant cells, and hemosiderin pigment. The scenario describes a central process, hence, this is not a peripheral giant cell lesion. Malignant osteoid is not noted in the section, nor is odontogenic epithelium. As such, osteosarcoma and ameloblastoma do not represent accurate diagnoses. Reference: Regezi JA, Scuibba JJ, Jordan RCK (eds) Oral Pathology: Clinical Pathologic Correlations, 4th Edition , Chapter 12, Benign Nonodontogenic Tumors, St. Louis, Elsevier Science, 300, 2003.

Answer 152

Answer: B Rationale: The histomicrograph clearly shows odontogenic epithelium in the background of a rich fibroblastic stroma. These findings support the diagnosis of ameloblastic fibroma. The histopathologic features do not support a diagnosis of ameloblastoma, ameloblastic fibro-odontoma or odontogenic keratocyst. Reference: Neville BW, Damm DD, Allen CM, Bouquot JE (eds) Oral and Maxillofacial Pathology, 2nd edition, Chapter 15, Odontogenic Cysts and Tumors, St. Louis, WB Saunders Co., 627, 2002.

Answer 153

C Rationale: The main advantages of a full thickness skin graft over a split thickness skin graft for facial reconstructive surgery include less contracture of the healing graft, and less labor regarding the donor site's postoperative management. This is owing to the ability to primarily close the donor site of a full thickness skin graft, while the donor site of a split thickness skin graft must heal by tertiary intention. During this time, the split thickness skin graft donor site must be dressed with an occlusive dressing such as Opsite or Tegaderm. With this in mind, the potential for postoperative infection is such that the closed wound may develop infection, while the defect pertaining to the split thickness skin graft is open, and therefore less likely to become infected postoperatively. Reference: Zide MF and Fuselier C The partial thickness cross-lip flap for correction of post-oncologic surgical defects. JOMS 59 1147, 2001.

Answer 154

Answer: B Rationale: Cessation of smoking should allow for gradual improvement in lung function. Nicotine with a half-life of approximately 30-60 minutes would fall precipitously with cessation of smoking for four hours prior to administration of the anesthesia. Although of some benefit, the stimulation of the sympathoadrenal system would take longer to normalize. Carboxyhemoglobin levels should approach that of a non-smoker after a smoke free period of approximately 48 hours. This should allow for increased availability of hemoglobin for oxygen transport. The hypersecretion of mucous requires a period of approximately six weeks to decline to normal levels after cessation of smoking. Alveolar macrophage, antimicrobial function has been shown to take six months or more to improve to that of a non-smoker. Narrowing of the bronchial airways and air trapping is another problem seen with smoking. Improvement in pulmonary function test generally requires a minimum period of six weeks of abstinence. Reference: Pearce AC, Jones RM. Smoking and Anesthesia: Preoperative abstinence and perioperative morbidity. Anesthesiology 1984; 61:576.