Dentoalveolar Surgery Flashcards

Question

What media can be used to transport avulsed teeth?

Answer 1

Saliva, fresh milk, or, preferably, Hanks balanced salt solution (HBSS). Water is harmful because, as a hypotonic fluid, it may cause periodontal ligament cell death when it enters cells down the osmotic gradient, causing cell lysis and death. Any tooth with an extraoral dry time of greater than 60minutes will have a poor prognosis for long-term success after replantation. Detailed protocols for management (based on dry time and whether the root apex is open or closed) are available on the website of the International Association of Dental Traumatology.

Answer 2

Up to 2 to 3 weeks.

Answer 3

Signs of close proximity of the mandibular third molar to the inferior alveolar canal are mostly radiographic in nature and include: • Darkening and notching of the root • Deflected roots at the region of the canal • Narrowing of the root • Interruption of canal outlines • Diversion of canal from its normal course • Narrowing of canal outlines on the radiograph

Answer 4

Of the previously listed signs of close proximity of the canal to impacted third molar, diversion of canal, interruption of canal borders, and darkening of roots are the most reliable signs.

Answer 5

• Swallowing or aspiration of foreign objects • Tissue emphysema • TMJ pain • Trismus • Mandibular fracture • Tuberosity fracture • Root fracture • Injuries to adjacent teeth • Displacement of root and root fragments into the submandibular space, mandibular canal, or maxillary sinus • Oral-antral communication, bleeding, infection, ecchymosis, and hematoma • Localized osteitis (dry socket) • Wound dehiscence • Inferior alveolar and lingual injuries Depending on the location and the nature of the surgery, these complications vary in severity and need for treatment.

Answer 6

Once displacement of a mandibular molar root into the submandibular space is suspected, manual lateral and upward pressure should be applied immediately on the lingual aspect of the floor of the mouth in an attempt to force the root back into the socket. If the root is visualized again in the socket, it may be retrieved from the socket with a root tip pick. If not, a mucoperiosteal soft tissue flap should be reflected on the lingual aspect of the mandible until the root tip is found; ensure that the mylohyoid muscle is sharply detached from its insertion in the mandible. Antibiotic coverage is indicated postoperatively. If the root is not visualized because of its location or uncontrollable bleeding, recovery is best performed as a secondary procedure when fibrosis occurs and stabilizes the tooth in a firm position, usually 4 to 6weeks later. The patient should be informed and be placed on a short course of antibiotics.

Answer 7

When displacement of a root into the mandibular canal is suspected, periapical and occlusal radiographs or cone beam CT scan should be taken for verification, because the root may be in a large marrow space or beneath the buccal mucosa. If the root is visualized, careful removal is indicated with a small hemostat after adequate alveolar bone removal. If the root is not visualized, delayed removal is recommended. Delayed removal is also indicated during persistent infection and nerve paresthesia. If the root fragment is small and does not become infected preoperatively, leaving the root in place is a viable and less invasive option.

Answer 8

Once the root is suspected to be in the sinus, place the patient in an upright position to prevent posterior displacement and obtain a radiograph or CT to determine its location and size. If the fragment is found to be in the sinus, local measures of retrieval should be attempted first, such as: • Having the patient blow through the nose with the nostrils closed, and observing the perforation for the root to appear in the socket • Using a fine suction tip to bring the root back into the defect • Performing antral lavage with sterile isotonic saline in an effort to flush the root out through the defect If local measures are unsuccessful, direct entry into the maxillary sinus via the Caldwell-Luc approach in the area of the canine fossa should be performed. Postoperative management includes a figure-ofeight suture over the socket (or flap closure if the opening is sizable), sinus precautions, antibiotics, and a nasal spray to keep the sinus ostium open and infection free.

Answer 9

Probing, irrigation, and having the patient blow forcefully with the nostrils occluded are contraindicated because these maneuvers may enlarge an existing opening or create one that did not previously exist. Some will allow patients to blow gently while compressing the nostrils to observe for air bubble formations that will confirm an antral opening. For openings <2mm, no surgical treatment is necessary, providing adequate hemostasis is achieved. For openings of 2 to 6mm, conservative treatment is indicated, including placement of a figure-of-eight suture over the tooth socket and sinus precautions (avoid blowing the nose, violent sneezing, sucking on straws, and smoking). For openings >6mm, primary closure should be obtained with a buccal flap or a palatal flap procedure. Approximation of the gingiva can be facilitated by removal of a small amount of the buccal alveolar plate and scoring or incising the periosteum on the underside of the flap. Placement of a small piece of absorbable gelatin sponge into the occlusal third of the socket when the gingival margins cannot be coapted is not advisable because it introduces a foreign substance and could lead to subsequent breakdown of the clot. Antibiotics and nasal or oral decongestants are prescribed if there is evidence of acute or chronic sinusitis.

Answer 10

When a maxillary third molar is displaced into the infratemporal fossa, it is usually displaced through the periosteum and located lateral to the lateral pterygoid plate and inferior to the lateral pterygoid muscle with displacement. If there is good access and adequate light, a single cautious effort to retrieve the tooth with a hemostat can be made. If the effort is unsuccessful, or if the tooth is not visualized, the incision should be closed, the patient should be informed, and prophylactic antibiotics should be prescribed. A secondary surgical procedure is performed 4 to 6weeks later after localization is determined using either lateral and posteroanterior radiographs or, preferably, a cone beam CT scan. After adequate anesthesia, a long needle—usually a spinal needle—is used to locate the tooth. Careful dissection is performed along the needle until the tooth is visualized and subsequently removed. Some surgeons may prefer to perform this removal in the operating room for better access. If no functional problems exist after displacement, the patient may elect not to have the tooth removed. Proper documentation of this is critical.

Answer 11

The first step in managing postoperative bleeding is to carefully examine and visualize the bleeding site to determine the precise source of bleeding. In the case of simple generalized oozing, a damp gauze is held over the site with firm manual pressure for 5minutes. If unsuccessful, the area should be anesthetized and examined more closely. If sutures were placed, they should be removed and the existing clot should be curetted from the socket. Hemostatic agents, such as an absorbable gelatin sponge, oxidized cellulose, or Avitene can be placed in the socket and sutured. If hemostasis is not achieved by local measures, lab screening tests should be performed to assist in diagnosis and treatment of the cause.

Answer 12

Often, after using local anesthesia with a vasoconstrictor, the extraction site appears “dry” and the void does not readily fill with blood. It is unnecessary and not a good practice to scrape the walls of the extraction site to stimulate bleeding or for any other reasons. This practice will delay healing. The remnants of the periodontal ligament (PDL) that are attached to the alveolar crypt are the sources of fibroblasts that form fibrin for the rudimentary clot (scaffold) upon which cells necessary for the healing process can migrate. Moreover, the remnants of the PDL provide small capillaries and pluripotential cells that will form osteoblasts necessary for bone formation.

Answer 13

For maxillary procedures, patients are positioned in a semireclined position, such that the maxillary occlusal plane is at an angle of about 60 degrees to the floor. This will normally correspond to a chair tilt of about 30 to 45 degrees from vertical or upright. The height of the mouth should be at the operator’s elbow level. For mandibular extractions, the patient should be more upright, so that the occlusal plane of the mandible is parallel to the floor when the mouth is opened. The patient will also be positioned slightly lower than for maxillary extractions, with the chair at or slightly below the elbow level of the operator. Operators who choose to perform exodontia while sitting will need to make appropriate modifications to the standing positions.

Answer 14

The spatial relationship between the lingual nerve and the mandibular third molar region is highly variable. The nerve has been found to be at the level of the lingual plate or higher, in contact with the lingual plate, or intimately attached to the periosteum and the follicular sac of the impacted mandibular third molar.

Answer 15

An excisional biopsy entails removal of the entire lesion along with at least 2mm of normal marginal tissue from the sides of the lesion. This technique is usually used for biopsy of a lesion 1 cm or less. An incisional biopsy removes only a representative portion or portions of a lesion along with a representation of adjacent normal tissue.

Answer 16

Whenever possible, the incisions should be oriented parallel to lines of muscle tension in order to minimize scarring and wound dehiscence.

Answer 17

The Pell and Gregory impacted third molar classifications are based on the third molar’s relationship to the anterior border of the ascending ramus and to the occlusal plane. A Pell and Gregory Class 1 impaction implies sufficient space between the ramus and the second molar into which the third molar can erupt. A Class 2 impacted third molar is found to be at least half covered by ramus bone. The Class 3 impacted third molar is entirely within the ramus. With regard to the occlusal plane, a Pell and Gregory Class A impaction implies that the occlusal surfaces of the second and third molars are at or about the same level. The occlusal surface of a Class B third molar impaction is between the occlusal surface and cementoenamel junction of the second molar. The Class C impaction is the deepest impaction where the occlusal surface of the third molar is completely below the neck of the second molar.

Answer 18

The most commonly impacted teeth are the third molars (mandibular more frequently than maxillary), followed in order by maxillary canines, mandibular premolars, and mandibular canines.

Answer 19

Standard unfractionated heparin (UFH) is formed from a heterogeneous combination of sulfated mucopolysaccharides. Its anticoagulant activity is unpredictable, so it must be carefully monitored with the partial thromboplastin time (PTT) test. LMWH (fractionated heparin) is formed from depolymerization of heparin into lower molecular weight particles. Because LMWH has increased bioavailability compared with UFH, it can be given as a fixed dose and without the need for monitoring with the PTT. It is useful in oral and maxillofacial surgery for some higher risk patients who cannot discontinue or reduce oral anticoagulation therapy. Patients stop warfarin therapy and the international normalized ratio (INR) is allowed to normalize while the LMWH is administered to maintain anticoagulation therapy. When the INR returns to an acceptable level, the surgery can be performed and scheduled for early in the day. The LMWH is withheld the day of surgery and resumed in the evening. Warfarin can be resumed the following day and the LMWH continued until the INR returns to the desired therapeutic range.

Answer 20

While each patient must be evaluated on an individual basis, it is generally not indicated to stop aspirin or Plavix prior to routine dentoalveolar procedures, including multiple extractions. Medical risks of recurrent myocardial infarction or stroke will outweigh the risk of postoperative bleeding in most cases. For more extensive procedures where there is a particular concern for bleeding, low molecular weight heparin (e.g., Lovenox) can be used.

Answer 21

Rivaroxaban (Xarelto) and apixaban (Eliquis) are direct Factor Xa inhibitors, and dabigatran (Pradaxa) is a direct thrombin inhibitor. Neither the INR nor Protime (PT) levels have been shown to have any reliability in monitoring therapy for these patients. Since the half-life of these agents is relatively short, they can be held for one or two days prior to surgery, based on their respective half-life. As a general rule, for drugs given twice daily (shorter half-life) hold for one day prior to surgery. For those given once daily (longer half-life), hold for two days prior to surgery

Answer 22

Mandibular tori usually need to be removed when a mandibular denture is being planned. The denture flange typically will impinge on these exostoses of bone. Palatal tori often do not need to be removed. Dentures often can be constructed over them. However, if a palatal torus is extremely large and fills the vault, extends beyond the dam area, has traumatized mucosal coverage, has deep undercuts, interferes with speech, or poses a psychologic problem for the patient, it should be removed. The tissue over mandibular tori is extremely thin and friable. Great care should be taken when elevating it. This tissue can be “ballooned” out by injecting some local anesthesia directly under it. The incision should be crestal or lingual circumdental. No releasing incisions should be made. After careful elevation of tissues, a groove can be cut along the intended line of removal with a fissure burr. A mallet and osteotome may be used to cleave the torus in this plane. After the bone has been smoothed and the area thoroughly irrigated, the wound can be closed. Gauze should be placed under the tongue to minimize the chance of hematoma. Before removing a palatal torus, a stent should be fabricated. This should be done on a study cast that has had the exostosis removed. A double-Y incision should be made over the midline of the torus. After careful elevation of the flaps, the torus should be scored multiple times in the anterior, posterior, and transverse dimensions. An osteotome can be used to remove each of these small portions. This decreases the risk of fracturing into the floor of the nose. A large burr or bone file is used to smooth the area. After thorough irrigation, the wound is closed with horizontal mattress sutures, and the stent is placed.

Dentoalveolar Surgery Flashcards

(46 cards)