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What are indications for surgical endodontics?

1. Periradicular disease associated with a tooth where iatrogenic or developmental anomalies prevent non-surgical RCT being undertaken
2. Periradicular disease in a root-filled tooth where non-surgical root canal retreatment cannot be undertaken or has failed or when it may be detrimental to the retention of the tooth
3. Where a biopsy of a periradicular tissue is required
4. Where visualisation of the periradicular tissues and tooth root is required when perforation or root fracture is suspected
5. Where it may no longer be expedient to undertake prolonged non-surgical RCT because of patient consideration


Define molar incisor hypomineralisation (MIH)

Hypomineralisation of systemic origin of 1-4 first permanent molars and frequently incisors


What is the prevalence of MIH?

3.6-25% (1 in 10 people are affected)


What is the clinical presentation of MIH?

1. Large demarcated opacities, whitish-yellow or yellowish-brown in colour
2. May be associated with post-eruptive breakdown resulting in exposed dentine and sensitivity (this is usually associated with the molars and rarely the incisors)


What is the aetiology of MIH?

1. Thought to occur between birth to 18 months
2. Occurs due to disturbance during the maturation phase of amelogenesis which causes damage to the ameloblast
3. Some of the causes of this disturbance include;
a) Asthma
b) Pneumonia
c) Otitis media
d) Antibiotics
e) Tonsilitis
f) Dioxins in breast milk
g) Hypoxia at birth


How do you diagnose MIH?

1. By examining wet, clean permanent molars and incisors
2. Done at the dental age of 8
3. Clinical findings include;
a) Absence or presence of demarcated opacities
b) Post eruption breakdown
c) Atypical restorations (failed restorations are often due to fracture)
d) Extractions due to MIH
e) Failure of eruption of molars/incisors (severe MIH)


Describe the histological feature of MIH

1. Increased carbon and magnesium
2. Decreased calcium and phosphorus (which makes it much weaker)
3. Decreased hardness and modulus of elasticity
4. Increased vascularity (suggesting inflammatory changes within the pulpal tissues)


What are the dental problems associated with MIH?

1. Poor aesthetics due to demarcation
2. Increased sensitivity which may affect toothbrushing
3. Increased caries level as their teeth break down much quicker
4. Increased anxiety due to increased dental complication


When is the ideal time to extract a first permanent molar?

1. At the dental age between 8-10 years old
2. There should be radiographic evidence of calcification of the bifurcation of the second permanent molar teeth
3. Ideally the third molars should also be present


List some of the treatments that could help patients with MIH

1. Fluoride varnish
2. Tooth mousse (casein phosphopeptide amorphous calcium phosphate) which works to remineralise teeth and helps with sensitivity problems
3. Applying fissure sealant and pre treat with 5% sodium hypochlorite (if they are not broken down)
4. Composite restorations (good aesthetics with superior wear resistance)
5. Stainless steel crowns in teeth with post eruptive breakdown and those with cuspal involvement
6. Cast gold/composite/ceramic onlays
7. Microabrasion of anterior teeth with shallow defects
8. Composite veneers
9. Porcelain veneers in late adolescence


What are effects of non nutritive sucking (NNS) on the developing dentition?

1. Decreased overbite or anterior open bite
2. Increased over jet
3. Higher incidence of class II canines or molars
4. Narrowing of the maxillary arch and increased mandibular arch width (leading to increased possibility of cross bite)


What are non dental effects of NNS?

1. Negative effect on breast feeding
2. Increased risk of otitis media
3. Increased risk of GI infection
4. Increased risk of oral colonisation with candida
5. Calloused and wrinkled digits
6. Consumption of honey during first year of life is linked to infant botulism


What are benefits of NNS?

1. Decreases peripheral sensitivity in newborns
2. Has a protective effect against Sudden Infant Death Syndrome (SIDS)


Describe the management of NNS

1. Reminder therapy such as adhesive bandage on the finger
2. Reward therapy
3. Elastic bandage around the elbow at night
4. Applying bitter tasting substance on finger
5. A fixed appliance with molar bands and anterior crib
6. Psychological assessment


At which age does the BSPD recommend to stop NNS?

By the age of 5


What are the different classification of crossbites?

1. Skeletal: crossbite with underlying skeletal basis (due to constricted maxilla and wide mandible)
2. Dental: crossbite due to distortion of dental arch when jaws are of normal proportion
3. Functional: crossbite caused by occlusal interference that requires the mandible to shift to achieve maximum occlusion


What is the aetiology of local crossbite?

1. Crowding (commonest cause): tooth is displaced from arch due to lack of space
2. Early loss of second primary molar: causing the premolars to erupt buccal or lingual to the arch
3. Over retention of primary tooth
4. Trauma to primary tooth


How does NNS cause crossbite?

1. Digit sucking is linked to posterior crossbite
2. This is due to forces exerted on the buccal segment as result of the negative pressure generated during digit sucking


Describe the management of a dental crossbite

1. In the presence of a deep overbite, a posterior bite block is first needed to correct the overbite
2. There must be adequate space in the arch to move the tooth into
3. After the crossbite has been corrected an adequate overbite is recreated to create stability for the new occlusion


What kind of appliance is used to correct a crossbite?

Removable appliance
1. Creates tipping movement
2. Has good anterior retention
3. Buccal capping is used to open up the bite
4. Z springs are the active component used to create the tipping movement


What are the advantages of using a removable appliance?

1. Easy to clean the teeth and appliance
2. Can transmit forces to blocks of teeth
3. Can tip teeth
4. Removes occlusal inference
5. Less chair-side time than fixed appliance


What are the disadvantages of using removable appliance?

1. May be left out of the mouth
2. Can affect speech
3. Inefficient for multiple tooth movements


How often should patients with active removable appliance be seen?

Every 3-4 weeks as more frequent activation will increase risk of anchorage loss and root resorption


When would fixed appliance be indicated for the management of crossbite?

1. When the apex of the incisor in crossbite is palatally positioned
2. When there is insufficient overbite to retain the corrected crossbite (fixed appliance enables the lower incisors to be moved lingually at the same time as the upper is moved labially)
3. When there are other aspects of malocclusion requiring fixed appliance are present


What are the advantages of fixed appliance?

1. Reduces need for patient cooperation
2. Increased control of tooth movements
3. Movement is possible in all 3 planes of space


What occurs in an ectopic first permanent molar (FPM)?

When there is alteration of the molar's eruption pathway leading to contact in the prominence of the distal surface of the second primary molar leading to surface resorption of the primary molar.


What are the two types of ectopic FPM?

1. Reversible (jump)
2. Irreversible (hold)


What is the prevalence of ectopic FPM?

1. 3-4% in the general population
2. 20% in the cleft lip population


What are the clinical presentation of ectopic FPM?

1. Canting of the occlusal plane of the second primary molar
2. Delayed eruption of the FPM
3. Distal cusp of FPM appearing before the mesial cusp
4. Mobile second primary molar


What is the radiographic presentation of ectopic FPM?

1. Upper FPM is superiorly and mesially positioned
2. Atypical resorption of the upper second primary molar


When is FPM usually diagnosed?

Between the ages of 5-7


How do you manage ectopic FPM?

1. Monitor: 66% are the jump type thus spontaneous self correction usually occurs
2. Separation: for the hold type, eruption is aided by separating the second primary molar from the FPM with wedge/wire/elastic


When is a tooth defined as having delayed eruption?

When the tooth on one side of the arch has erupted and six months later there is no sign of the equivalent on the other side.


What are the generalised causes of delayed eruption?

1. Down syndrome
2. Cleidocranial dysostosis (congenital disorder where there is delayed ossification of midline structures)
3. Gardner syndrome
4. Cleft lip and palate
5. Malnutrition
6. Hereditary gingival fibromatosis
7. Prematurity/low birth weight


What are localised causes of delayed eruption?

1. Supernumerary tooth
2. Congenital absence
3. Crowding
4. Delayed exfoliation of primary predecessor
5. Traumatic injuries to primary teeth
6. Dilaceration
7. Primary failure of eruption


List features of supernumerary teeth

1. The most common cause of delayed eruption of the maxillary permanent incisor tooth
2. Prevalence of 2% in the permanent dentition and less than 1% in the primary dentition
3. Supernumerary in primary dentition > supernumerary in the permanent dentition
4. Commonly occurring in the maxillary midline and third molar area


What are the different classification of supernumerary teeth?

1. Supplemental (resembles a tooth): usually at the end of a tooth series (2s, 5s and 8s)
2. Conical (peg shaped): often presents as a mesiodens between upper central incisors (rarely delays eruption)
3. Tuberculate (barrel shaped): commonly palatal to central incisors (classically associated with delayed eruption)


What are the two forms of odontomes (tumour of odontogenic origin)?

1. Complex: totally disorganised
2. Compound: bear some similarity to normal tooth


What is the most common cause of dilaceration and at which age is the permanent tooth at most risk of damage?

1. Intrusion or avulsion of A or B into the developing tooth germ
2. Under the age of 3 is when trauma is most likely to cause dilaceration to the permanent successor as the tooth germ is undergoing development


What are the different managements of supernumerary tooth?

1. When we notice supernumerary in a young child, we first observe it as not all supernumerary cause delay in eruption
2. However when it creates an obstruction, we will surgically remove it
*in the case of delayed eruption of 1, removal of the supernumerary along with the C allows the 2 to drift into the space which promotes eruption of the 1


What is the prevalence of ectopic canine?

A prevalence of 1.5% with 85% being palatally displaced and 15% bucally. It is twice as common in females


What is the aetiology of ectopic canine?

1. Polygenic and multifactorial
2. Absent/diminutive lateral incisors
3. Class II Div 2 malocclusion
4. 8% of ectopic canines are bilateral which suggests a genetic link


What are the risks associated with ectopic canine?

1. Root resorption of adjacent teeth
2. Cystic changes
3. Partial eruption subjects the tooth to the bacteria in the oral environment thus making them susceptible to infection
4. Loss of arch length


What are the clinical signs suggestive of an ectopic permanent canine?

1. Prolonged retention of the primary canine beyond 14 years
2. Delayed eruption of the permanent canine
3. Absence of labial canine bulge
4. Presence of palatal bulge
5. Distal tipping/mobility/loss of vitality of lateral incisors


When is cone beam CT indicated for ectopic canine?

To assess root resorption of the lateral incisor


What are the different treatment options for an ectopic canine?

1. Extraction of the primary canines before the age of 11: as 78% revert to normal path after the extraction
2. No active treatment: to monitor the ectopic canine and maintain the primary canine
3. Auto transplantation of the canine: must be done as atraumatic as possible to avoid ankylosis
4. Extraction of the ectopic canine and movement of the first pre molar to fill the space
5. Prosthetic replacement of the canine
6. Surgical exposure of the ectopic canine and orthodontic alignment of the tooth into the arch


What causes infraocclusion of teeth?

1. As a result of ankylosis, the tooth remains static
2. However eruption of adjacent teeth continues
3. This results in the infraocclusion tooth lying below the occlusal plane


What is the prevalence of infraoccluding primary molars?

1. It has a prevalance of 9%
2. It is x10 more common in the primary dentition
3. Usually develops during the early mixed dentition
4. May affect both the maxilla and mandible
5. May be bilateral or unilateral


When is surgical intervention of the infraoccluded primary molar indicated?

1. When the infraoccluded tooth has reached below the gingival margins
2. When the FPM (6) has tipped over it


What are the three severity of infraocclusion?

1. Slight submergence: the entire occlusal surface is located at least 1mm below the occlusal plane of the adjacent non-ankylosed teeth
2. Moderate submergence: the entire occlusal plane is located approximately level with the contact area of one or both adjacent tooth surfaces
3. Severe submergence: the entire occlusal surface is level with or below the gingival margin of one of both adjacent tooth surfaces


What are the consequence of infraoccluded teeth?

1. Delayed exfoliation (by 6-12 months compared to contralateral tooth)
2. Denuding of proximal root surface
3. Increased difficulty of extraction
4. Reduced alveolar bone support
5. Progression of submergence
6. Delayed eruption of successor
7. Over eruption of opposing tooth
8. Damage to adjacent teeth


What are the effects of infraoccluded primary molar to the adjacent teeth?

A) Damege
1. Carious lesion to the adjacent FPM as patient in unable to clean the area
2. Exposed cementum on the mesial aspect of FPM may cause loss of periodontal attachment
B) Tipping
1. When the trans-septal fibres that link approximal root surfaces together are pulled below the occlusal plane, it causes tipping of the adjacent teeth
C) Retained Root Fragments
1. This may be retained when a brittle ankylosis tooth is extracted or may occur when infraoccluded tooth exfoliates


Define hypodontia

The developmental absence of one or more teeth in the primary or permanent dentition excluding third permanent molars


What is the prevalence of hypodontia?

1. 0.1-0.9% in the primary dentition
2. 3.5-6.5% in the permanent dentition
3. Mandibular second premolar > maxillary lateral incisor > maxillary second premolars > mandibular incisors


What is the aetiology of hypodontia?

A) Environmental
1. Infection: rubella, osteomyelitis
2. Trauma
3. Drugs: thalidomide
4. Chemotherapy
5. Radiotherapy
B) Genetic
1. Autosomal dominant trait with incomplete penetrance


What are the presentation of ectodermal dysplasia?

1. Multiple missing teeth (a syndrome linked to hypodontia)
2. Fine sparse hair
3. Maxillary hypoplasia (lack of bone to lack of teeth)
4. Eversion of the lips
5. Pigmentation around eyes/mouth
6. Small conical teeth


What is the genetic basis of ectodermal dysplasia?

Commonly X linked hypohydrotic form


What are the dental manifestations of Down syndrome?

1. Hypodontia (prevelance of 40-60%)
2. Microdontia (small teeth)
3. Ectopic canine teeth
4. Taurondontism (long coronal aspect of root canal usually occurring in the FPM)
5. Infraocclusion


What is the management of hypodontia?

1. Accept the space present
2. Space closure
3. Redistribution of space
4. Removable partial denture
5. Adhesive and conventional bridgework
6. Transplant
7. Implants


What are the factors contributing to high frequencies of medical emergencies in the dental practice?

1. High anxiety and stress
2. Medically compromised patient
3. Physiological stress
4. Potent drugs used in dentistry


What are the common cause of collapse?

1. Cardiac arrest
2. Fainting
3. Hypoglycaemia
4. Anaphylaxis
5. Epilepsy
6. Steroid insufficiency


What is the cause of cardiac arrest?

1. Sudden loss of an effective heartbeat resulting in acute failure of cardiac output
2. This could develop as result of
a) Myocardial infarction
b) Hypoxia
c) Severe hypotension from other cause
d) Respiratory arrest
e) Anaesthetic overdose


What kind of heart rhythm would you see in patient who are having a cardiac arrest?

1. Ventricular fibrillation (where the heart looks like a bag of worms)
2. In this scenario you can use a defibrillator which stops the heart momentarily to allow the nodes to regain control of coordinating the heart muscles


What are signs and symptoms of a cardiac arrest?

A) Immediate Signs
1. Sudden loss of consciousness
2. Absent pulse
B) Late Signs
1. Cyanosis
2. Dilated pupils and absent light reflex
3. Unmeasurable BP


What is the management of cardiac arrest?

1. Lay patient flat or head down
2. Get help
3. Starts BLS


What are steps that could be taken to prevent patients fainting in the surgery?

1. Note any previous history
2. Check that patient has eaten
3. Comfortable environment
4. Minimise stress
5. Lie patient supine when giving LA


What are signs and symptoms of fainting?

1. Patient feel dizzy, weak and nausea (can prevent faint by lying them down)
2. Pale, cold and clammy skin
3. Loss of consciousness
a) Shallow and irregular breathing
b) Pulse is weak, threads and slowly
c) BP drops
d) Muscle twitching and convulsion (this happens if you don't lay them down flat)


What causes postural hypotension?

1. Prolonged periods of lying down
2. Common in the elderly
3. Common in patient on anti hypertensive
4. Influenced by alcohol


What is the signs and symptoms of postural hypotension and its management?

A) Signs and symptoms
1. Collapsing on standing
B) Management
1. Lay patient flat or head down
2. Slowly transition the patient to standing


What are the signs and symptom of hypoglycaemia?

A) Effects on brain
1. Increasing drowsiness
2. Disorientation
3. Excitability
4. Slurred speech
B) Effects due to release of adrenaline (sympathetic response)
1. Shaking
2. Sweating
3. Palpitation
4. Pins and needles


What is the management of hypoglycaemia?

A) Conscious patient
1. 50g of glucose orally (as a drink)
2. Alternative: any other forms of sugar
B) Unconscious patient
1. 1mg glucagon IM
2. Alternative: 50ml of 30% glucose IV
3. Put the patient in recovery position
4. Once the patient gains consciousness > administer glucose


What common causes of anaphylaxis in the dental practice?

1. Drugs such a penicillin or LA agent
2. Latex
3. Chlorhexidane


What are the signs and symptom of anaphylaxis?

1. Facial flushing/swelling
2. Urticaria (hives)
3. Wheeze/difficulty breathing
4. Loss of consciousness
5. Rapid weak pulse
6. Falling BP
7. Pallor going in cyanosis
8. Cardiac arrest (end result)


What is anaphylaxis?

A severe and systemic type I hypersensitivity reaction


What is the management of anaphylaxis?

1. Lay head down and maintain airway
2. Oxygen
3. 0.5ml if 1:1000 adrenaline IM
4. Call for medical help
5. Additional medication:
a) Antihistamine: chlorphenamine 10-20mg IV
b) Hydrocortisone: 200mg IM or IV (helps with mast cell degranulation)


What are the signs and symptoms of epilepsy?

A) Aura phase
1. The part affected depends on the part of brain having excessive activity (could be hearing etc)
B) Tonic phase (muscles contract)
1. Loss do consciousness
2. May cry out or become cyanotic
C) Clonic phase
1. Jerking of limbs
2. Tongue may be bitten
3. Incontinence or frothing at mouth


What is the management of epilepsy?

A) During fit
1. Protect patient from injury
B) After fit
1. Recovery position
2. Maintain airway
C) When conscious
1. Sympathy and reassurance
2. Observe until fully recovered
3. Send home with escort


How does status epilepticus vary from grand mal seizure?

Status epilepticus involves prolonged and repeated fits which leads to inability of the brain to go back to its normal state


What is the management of status epilepticus?

1. After 5 minutes of continuous fits, administer 10mg of liquid midazolam bucally
2. Alternative: diazepam 10mg IV
3. Monitor respiration (as midazolam is a respiratory depressant)
4. Give oxygen
5. Call for help


What are the two main causes of a steroid collapse?

1. Primary adrenal insufficiency (Addison's disease)
2. Secondary adrenal insufficiency due to chronic steroid use


How is steroid cover provided?

A) Minor surgery
1. Double the normal dose of oral steroid the night before and day of operation
2. 100mg hydrocortisone IM 30mins before or IV immediately before the procedure
B) Major surgery
1. 200mg hydrocortisone IM 30 minutes before or IV immediately before the procedure and 6 hourly for up to 72 hours


What are the signs and symptoms of a steroid collapse?

1. Pallor
2. Loss of consciousness
3. Rapidly falling blood pressure
4. Weak pulse
5. Failure to regain consciousness when laid flat


What is the management of a steroid collapse?

1. Lay patient flat
2. Administer oxygen
3. Urgent transfer to hospital


Explain airway in ABCDE

A) Total obstruction
1. Paradoxical movement (where the lung collapses in and expands)
2. Accessory muscle use
3. Central cyanosis
B) Partial obstruction
1. Diminished air entry
2. Noisy breathing (stridor, wheezing, snoring)
C) Treatment
1. Head tilt chin lift
2. Remove foreign body
3. Oxygen: 10L/min by mask


Explain breathing in ABCDE

A) Assess
1. Count respiratory rate: 12-20 breaths per minute
2. Quality of breath (depth and rhythm)
B) Management
1. Bag and mask with oxygen
2. Pocket mask with oxygen


Explain circulation in ABCDE

A) Assess
1. Skin colour
2. Limb temperature
3. Capillary refill time
4. Count pulse rate
B) Management
1. Fluid replacement
2. Fluid challenge (bolus of solution)


What are the signs and symptoms of acute chest pain?

1. Crushing retrosternal chest pain
2. Pain may radiate to arm, neck and jaw (usually on the left)


What are the features suggesting angina related chest pain?

1. Short lasting pain
2. Reversible pain in resting and with glyceryl trinitrate


What are the features suggesting MI related chest pain?

1. Pain that is persistent, irreversible and more severe
2. Breathlessness
3. Nausea and vomiting
4. Loss of consciousness
5. Weak or irregular pulse


What is the management of acute chest pain?

1. 0.5mg of GTN sublingually
If chest pain is not relived by GTN
2. 300mg of aspirin to be crushed intra orally
3. Reassure patient and allow patient to rest in a comfortable position
4. 10L/min oxygen or 50:50 oxygen and nitrous oxide
5. Monitor the patient


What are the signs and symptoms of acute asthmatic attack?

1. Wheezing
2. Breathlessness
3. Accessory muscle or respiration
4. If severe:
a) Respiratory rate >25 per minute
b) Heart rate >110 per minute


What is the management of acute asthmatic attack?

1. Keep patient upright and reassure
2. Use patient's bronchodilator (100mg Salbutamol per actuation)
3. Repeat if necessary
If symptoms persist
4. Call ambulance
5. Give oxygen 10L/min
6. Give nebuliser 5mg salbutamol (ventolin)


What are the signs and symptoms of inhaled foreign body?

A) Upper airway
1. Cough reflex stimulated
2. Causes choking if large enough to cause obstruction
a) Wheeze
b) Stridor
c) Silent with paradoxical chest movements
B) Lower airway
1. May be completely symptomless


What is the management of an inhaled foreign body?

A) No choking
1. Check if object is still in mouth
2. If object is not found place chair head down to oropharynx where it may be retrieved
If object cannot be retrieved inform the patient and send to hospital for further assessment
B) Difficulty breathing
1. Encourage coughing
2. Give 5 sharp thumps between the shoulder blades
C) If choking
1. Use Heimlich manoeuvre 5 times in quick succession
D) If patient becomes unconscious
1. Start CPR


What are the minimum requirements for a referral letter?

1. Date
2. Ideally type written
3. Signed
4. Name/ address/ DOB/ telephone number (of patient)
5. Brief history including complaints and finding
6. Relevant medical and dental history
7. Treatment provided
8. Whether advice or treatment is needed
9. Whether it's urgent or not
10. Recent high quality radiographs if indicated


What are the features of endodontic treatment that can be carried out by normal GDP?

1. Single/multiple canal with curvature with less than 15 degrees
2. Negotiable canals
3. No canal obstruction
4. Incision and drainage


What are the features of endodontic treatment that can be carried out by GDP with additional competencies?

1. Single/multiple canal with curvature more than 15 degreesbut less than 40 degrees
2. Incomplete root development
3. Slight limitation of mouth opening
4. Retreatment without complication


What are the features of endodontic treatment that can be carried out by specialist?

1. Single/multiple canals with curvature more than 40 degrees
2. Canals not considered to be negotiable through out their length
3. Periradicular surgery
4. Iatrogenic damage or pathological resorption
5. Difficult root morphology
6. Limited mouth opening
7. Complicated retreatment (fractured instrument)


What are the clinical presentation that warrants an oral medicine referral?

1. Red and white patches where cancer is not suspected
2. Pigmented oral lesion
3. Oral lumps
4. Oral ulcers
5. Infection in the oral cavity
6. Oral manifestation of systemic disease
7. Dry mouth
8. Oro facial pain of non-dental origin
9. Precancerous oral lesion


What are some indications for paediatric referral?

1. Children with complex medical history
2. Children with developmental problems, learning difficulties and behavioural problems
3. Children with congenital or acquitted dental anomalies
4. Children with early onset of periodontal problems
5. Children with clef lip and palate (and other cranio-facial abnormalities)
6. Children who require surgical procedure such as removal of supernumerary, infraoccluded or impacted teeth
7. Children with complex dento-alveolar trauma


What are the referral criteria for provision of dental implants under the NHS?

1. As part of reconstructive treatment to the mouth following oncology surgery
2. As part of oral and facial reconstructive treatment following severe facial trauma (involving the teeth)
3. Rehabilitation of patient with congenital defect
4. Where there are severe eating/ speaking disorder or psychological problems arising from the inability to wear conventional denture prosthesis
5. Where previous dental implant treatment has been unsuccessful and further treatment us recommended as ideal treatment option


What are the two terms interchangeable with ICP?

1. Centric occlusion
2. Maximum intercuspation position


Define ICP

Inter cuspal position; position of maximum interdigitation of the teeth with the mandible at its most cranial position


Define RAP and RCP

Retruded axis position; the mandibular-maxillary relationship when the condyles are in their upper most and most anterior position in the glenoid fossa
Retruded contact position; the point of first tooth-tooth contact in RAP


What is the discrepancy between RCP and ICP?

1.25mm (+/- 1mm)


Define group function

Two or more pairs of teeth on the working side contact during excursion


Distinguish Pankey-Mann-Schuyler from Gnathology

1. Patient provides the function information
2. Aims to create harmony in the occlusion
1. Articulating provides the functional information
2. Aims to create organisation in the occlusion


Describe the principles of posterior stability

1. Sufficient posterior teeth to make contact such that
a) The mandible is able to close reproducibly into a stable position
b) The front teeth do not receive excessive loading
2. The mandible should be able to close easily into ICP without being deflected from one path to another


Describe the principles of canine guidance

1. Only canines on the working side contact during excursion
2. Produces a mutually protected occlusion
a) Posterior teeth protects anterior teeth from heavy loads in ICP
b) Anterior teeth protect posterior teeth from oblique loads in excursion


What are the four key elements in good occlusion?

1. Biomechanical consideration
a) Light axial loading (avoid oblique load)
b) Transmit forces to the teeth/implant/denture base safely
c) Relatively stable over time with minimal wear
2. Posterior stability
3. Anterior guidance
4. Avoidance of interferences


Describe the principles of anterior guidance

1. Concept of disclusion
a) During lateral excursion contact of teeth on the working side separates those on the non working side
b) Contact of anterior teeth separate posterior teeth during protrusive movement
2. Character of the guiding surface (smooth and no steep rises) is more important than which teeth provide the guidance


State Hanau's Quint

1. Inclination of condylar guidance
2. Prominence of compensating curve
3. Inclination of plane of orientation (occlusal plane)
4. Inclination of the incisal guidance
5. Height of cusp


Distinguish between normal and parafunctional activity

A) Normal
1. Duration of tooth contact in a day: 4-10 mins
2. Magnitude of applied force: 20-40 lbs per square inch
3. Direction of applied force: vertical
B) Parafunctional
1. Duration of tooth contact in a day: 4-5 hours
2. Magnitude of applied force: up to 300 lbs per square inch
3. Direction of applied force: horizontal


What are the signs of occlusal disharmony?

1. Excessive tooth wear
2. Fractured teeth and restoration
3. Debonding of crowns and bridges
4. Mechanical failure of restoration
5. Tooth mobility/ drifting of anterior teeth
6. Localised bone loss (in the presence of existing perio disease)


What are symptoms of occlusal disharmony?

1. Post cementation pain
2. Pain following placement of direct restoration/ endodontic
3. Pain from muscles related to mandibular movement
4. TMD symptoms


Define an articulator

Mechanical device which represents the TMJ and jaw members to which maxillary and mandibular casts may be attached


What are the two uses of articulators?

1. Diagnosis: requires accurate mounted study cast, facebow and centric relation record
2. Restoration: requires working cast, bite registration in ICP


What are the different types of articulator?

1. Hand held cast
a) Used only when there is adequate number of teeth present
2. Simple hinge
a) Can reproduce ICP
b) Cannot alter vertical dimension
c) Inaccurate lateral and protrusive excursion
d) Can be used for single unit crowns
3. Semi adjustable
a) Commonly used
b) Can be Arcon or non-Arcon
c) Requires facebow record
d) Centric relation record is needed for accurate mounting
e) Used in most restorative treatment
4. Full adjustable
a) Can reproduce all movements of the mandible
b) Not necessary for the majority restorative work in general practice


What are the benefits of using a facebow?

1. Records the distance from TMJ joints to upper teeth
2. Records the relationship between maxillary plane and inter pupillary line (aesthetic purposes)


Distinguish Arcon and non-Arcon articulators

1. An Arcon articulator has the condylar element in the lower member of the articulator (anatomical)
2. A non-Arcon articulator has the condylar element in the upper member of the articulator (not anatomical)


What is the function of a facebow?

Records relationship between the patient's terminal hinge axis and the maxillary teeth enabling this to be transferred to the articulator


What is an occlusal interference?

A tooth to tooth contact that prevents or hampers smooth mandibular movement


What are the three occlusal approaches in restorative dentistry?

1. Confirmative: accept existing relationship and work to it
2. Localised occlusal adjustment: making minor changes whilst working to existing relationship
3. Reorganised: creating new relationship typically so that ICP=RCP


What are the indications for reorganising a patient's occlusion?

1. Large number of tooth surfaces are to be restored
2. TSL
3. Absence of ICP
4. When space is needed for restoration


What are the effects of tooth loss?

1. Aesthetics
2. Function
3. Drifting of adjacent teeth
4. Over eruption opposing teeth
5. Tilting of adjacent teeth
a) Upper teeth tilt mesially and rotate in the axis of palatal root
b) Lower teeth tilt in mesial direction


What are the factors affecting drifting of neighbouring teeth?

1. Intercuspation
2. Age
3. Periodontal health
4. Tooth


What are the effecting of drifting teeth?

1. Occlusal derangements
2. Premature contact
3. Occlusal trauma
4. Caries


What are the treatment options for replacing an edentulous space?

1. Orthodontics
2. Implant
3. Removable prosthesis
4. Fixed prosthesis


What are the tooth related factors to consider when deciding between fixed or removable prosthesis?

1. Number of abutments
2. Number of teeth lost
3. Position of teeth lost
4. Periodontal condition
5. Need for RCT
6. Ridge quality
7. Conservative status
8. Occlusal consideration


What are the contradiction for bridges?

1. Factors affecting the crown
a) No coronal tooth tissue left
b) Angulation of the crown
c) Insufficent intra occlusal clearance
2. Factors affecting the root
a) Short root
b) Need for re-RCT
3. Length of span
4. Possibility of further tooth loss
5. Unfavourable tilting


Define a bridge

An appliance replacing one or more teeth that cannot be removed by the patient


What is the percentage of crowned teeth becoming non vital?



State the different components of a bridge

1. Pontic: artificial tooth as part of the bridge
2. Unit: either a retainer or pontic
3. Connector: connects pontic to retainer


What are the different types of bridges?

A) Fixed movable
1. Stress distributing device which allows limited movement to one joint
2. Conservative
3. Can be used on divergent abutments
4. Strong major retainer required
B) Cantilever
1. Pontic is connected to retainer at one end only
2. Conservative, aesthetic and simplify plaque control
3. Requires light occlusal force
C) Spring cantilever
1. Supports a pontic at a distance from the retainer
2. Tooth and tissue supported
3. Supplies an aesthetic solution to missing upper central
D) Resin bonded
1. Cast metal framework cemented with resin composite
2. Preparation is confined to enamel
3. Bridges with no preparation often failed
4. Requires careful choice of abutments


What are the requirements for resin bonded bridges?

1. Space for aesthetic pontic
2. Sufficient enamel for bonding
3. Minimal restoration
4. Adequate occlusal clearance
5. Pontic is guarded in function


What is the survival rate for bridges?

1. 5% failure at 5 years
2. 30% failure at 15 years
3. Complications include
a) Abutment teeth becoming non vital
b) Debonding (1/20 RBB debond every year)
c) Caries
d) Abutment teeth lost due to periodontitis


Define marginal gap

1. Perpendicular distance from the margin of the crown preparation to the inner surface of the crown
2. It is 100 microns
3. It can be equal to absolute margin discrepancy (when there is no overextension of the crown gingivally)


What are some cause of gingival recession after placement of crown?

1. Crown margin is not optimum (incorrect emergence profile)
2. Crown margin is below the gingival margin
3. Thin gingival biotype


Describe features of the RPI system

1. Mesial rest: ensures even loading to the ridge
2. Distal guide plate: which slides and disengages when load is applied to the saddle
3. I bar clasp: disengages from the bulbosity of the tooth when the saddle moves into the ride


How does guide planes improve denture design?

1. They allow displacement in one direction thus improve denture retention
2. They also improve aesthetics as no clasp are visible and the flange fits up agains the labial tissues
*they are identified during the surveying stage


How long is a twin block appliance usually given to patients?

9 months to 1 year


What are two types of orthognathic surgery?

1. Le fort osteotomy: allows maxilla to be manipulated
2. Sagittal split osteotomy: allows mandible to be manipulated


What are the three phases of orthodontic treatment?

1. Phase I: teeth are lined to make them straight
2. Phase II: close any space or overjet
3. Phase III: finish off any additional alignment needed


What is the ideal age for orthodontic treatment?

12-13 years old due to improved compliance


What is A in ABCDE of a primary survey done on trauma patients?

Airway maintenance with cervical spine protection
1. Airway patency check
2. Inspection for fractures
3. Chin lift or jaw thrust
4. Avoid hyperflexion or rotation
5. Use immobilisation device
6. Get a cervical spine radiograph


What is B in ABCDE of a primary survey done on trauma patients?

Breathing and ventilation
1. Expose patient's chest to assess movement
2. Identify; tension pneumothorax, flail chest, massive haemothorax, open pneumothorax
3. Oral or nasal endotracheal intubation with cervical spine protection and ventilation
4. Supplemental oxygen and pulse oximeter
5. Surgical airway management if oral/nasal intubation not possible (needle or surgical cricothyroidotomy)


What is C in ABCDE of a primary survey done on trauma patients?

Circulation with haemorrhage control
1. Assess blood volume and cardiac output
a) Level of consciousness
b) Skin colour
c) Pulse
d) Bleeding
2. Identity and control bleeding with manual pressure
3. Take a blood sample for type, crossmatch, haematology
4. Crystalloids microwaved to 39 degrees
5. Minimum of 2 large-caliber IV cannulae


What is D in ABCDE of a primary survey done on trauma patients?

Disability which included neurological evaluation
1. Glasgow coma scale (GCS)
2. Decreased consciousness may indicate
a) Reduced cerebral oxygenation
b) Direct cerebral injury
c) Hypoglycaemia
d) Alcohol, opioids or other drugs


What is E in ABCDE of a primary survey done on trauma patients?

Exposure or environmental control
1. Undress the patient to enable thorough examination
2. Cover patient with blanket to prevent hypothermia
3. Also warm all IV fluids


What are the supplemental examination to the primary survey done on trauma patients?

1. Electrocardiographic monitoring
2. Urinary and gastric catheter
a) Urinary catheter measures urine output and renal perfusion
b) Gastric catheter reduces risk of aspiration
3. Monitoring of pulse, BP, ventilatory rate, blood gas analysis, body temperature and urinary output
4. Radiographs
a) AP chest film
b) AP pelvis
c) Lateral cervical spine


What are features of the maxillofacial examination done during the secondary survey in trauma patients?

1. Laceration, bruising, swelling or paraesthesia
2. Assess bony margins
3. Asses eyes for visual acuity and signs of
a) Circumorbital ecchymosis (black eye)
b) Subconjunctival haemorrhage
c) Diplopia
4. TMJ
a) Opening
b) Lateral excursion


What are features of the neurological examination done during the secondary survey in trauma patients?

1. Motor and sensory evolution of extremities
2. Assess level of consciousness, pupillary size and response


What are the instructions given to patient with recent head injuries?

1. Drowsiness
2. Nausea or vomiting
3. Convulsion or fits
4. Bleeding or watery drainage from nose or ear
5. Severe headaches
6. Weakness or loss of feeling in the arm or leg
7. Confusion or strange behaviour
8. One pupil lager than the other or double vision
9. Very slow/rapid pulse or unusual breathing pattern
*patient should not drink alcohol for 3 days or take any strong pain killers


What is the equivalent GCS score for coma or severe brain injury?

GCS of 8 or less


What are two common areas where a haematoma develop within the brain?

1. Subdural (30%)
2. Epidural (0.5%)


What are the medical therapies for brain injury?

1. Intravenous fluid
2. Hyperventilation (makes patient alkalotic > constricts baroreceptors > reduces blood flow to the brain)
3. Mannitol
4. Steroids
5. Anti convulsants


What are the surgical management of brain injury?

1. Scalp wound debridement
2. Elevation of depressed skull fracture
3. Evacuation of haematoma


What are the causes of facial fractures?

1. Interpersonal violence
2. Self harming
3. Road traffic accidents
4. Falls including accidental and medical
5. Sports
6. Pathological
7. Iatrogenic


What are the different places a mandible can fracture?

1. Body
2. Symphysis
3. Condylar
4. Ramos
5. Angle
6. Coronoid process
7. Condylar
8. Subcondylar


What are the clinical presentation of mandibular fracture?

A) Symptoms
1. Pain
2. Swelling
3. Paraesthesia of lower lip and chin
4. Altered occlusion, step deformity
B) Signs
1. Floor of mouth haematoma


What are the two commonly used methods for fixing a fractured mandible?

1. Intermaxillary fixation using archbars or eyelets and wire or elastics
2. Open reduction and internal fixation (ORIF) using mini plates


Compare the advantages and disadvantages of IMF and ORIF

✖️ Airway is compromised
✖️ Difficult delivery of asthmatic medication
✖️ Eating restricted to liquid diet
✖️ Speech is compromised
✖️ Oral hygiene is compromised
✔️ Excellent occlusion and bony reduction
✖️ Risk of facial nerve injury
✖️ Risk of devascularisation in the edentulous mandible (due to blood supply coming from periosteum)
✔️ All the disadvantages of IMF is not a problem in this technique


What are signs and symptoms of a dislocated mandible?

1. Patient in excruciating pain
2. Patient with their mouth wide open and are unable to close their mouth


How do you manage a dislocated mandible?

1. Early reduction without anaesthesia or with conscious sedation
2. They may require IV midazolam to relax the muscles
3. Reduction should be done straight away with preoperative advice given to prevent the dislocation from recurring


What are signs and symptoms of zygomatic fracture?

A) Symptoms
1. Pain
2. Swelling
3. Paraesthesia of the cheek, gums and teeth
B) Signs
1. Eye signs
a) Circumorbital ecchymosis
b) Subconjuctival haemorrhage
c) Diplopia
d) Enopthalmos (sinking of the eyeball into the socket)
2. CSF leak
3. Deranged occlusion


How do manage a zygomatic complex fracture?

Reduction and fixation
1. Rowe's elevator via Gillies temporal approach
2. Open rejection and internal fixation (ORIF) using miniplates


What are the management for a retrobulbar haemorrhage?

1. IV steroids
2. IV mannitol
3. IV acetazolamide
4. Surgical decompression


What is the regulation regarding X-ray that is principally concerned with the safety of workers and general public?

Ionising Radiation Regulation 1999


What is the regulation regarding X-ray that is principally concerned with the safety patients?

Ioninising Radiation (Medical Exposure) Regulations 2000


Define an X-ray

Wave packet of energy called a photon with high energy and short wavelength


List the main properties of X-Ray

1. Part of electromagnetic spectrum
2. Travel in straight lines
3. Requires no medium and undetected by human senses
4. Originate from a sudden energy change at the atomic level
5. Describes a beam due to the large number of photons produced
6. High energy photons have high penetrability
7. Low photons have low penetrability and therefore easily absorbed
8. X-ray affects film emulsion to cause a visual image
9. Can be attenuated by matter (absorption + scatter)


What are the two nature of ionising radiation?

A) Tissue reaction (deterministic effect)
1. Early: skin erythema etc
2. Late: osteoradionecrosis
3. Dose dependant
4. Only involves somatic cells
5. Recovery processes occurs
B) Stochastic effect
1. Cancer induction due to mutation of somatic cells
2. Heritable disease in offspring due to mutation of germ cells
3. No known threshold dose
4. Chance of effect increases with dose of radiation received
5. No recovery process


What are the aims of radiation protection?

1. Prevent detrimental tissue effect
2. Limit the probability of genetic effect


Define FSD

Focal spot distance is the distance from the focal spot on the target to the end of the spacer cone that touches the patient's face


What are the two forms of X-ray produced?

1. Continuous spectrum
2. Characteristic spectrum


What are the two variables in an X-ray set?

A) Kilovoltage
1. Determines the quality of X-ray beam (energy of the photons)
2. Determines the penetrating power of the photons
3. Affects film contrast
B) Current and time
1. Determines the quantity of X-ray photons
2. Affects the degree of blackening of the film


What is alternating current rectified to direct current in X-Ray sets?

1. Allows the kilovoltage to be kept at positive X-ray peaks through out any exposure
2. Leads of production of more high energy photons per exposure
3. Reduces the amount of low energy (harmful) photons that are produced
4. Enables a shorter exposure time


What are the four interaction of X-ray with matter?

1. Pure scatter: no loss of energy
2. Scatter + absorption: some loss of energy
3. Transmitted unchanged
4. Absorbed: photon disappears


Explain what happens in pure absorption of X-ray photon (photoelectric interaction)

1. Incoming X-ray photon interacts with a bound inner shell electron
2. As the density (atomic number, Z) increases the number of bound inner shell electrons also increases
3. Probability of photoelectric interaction is proportional to Z^3


Explain what happens in scatter and absorption of X-ray photon (Compton effect)

1. Incoming X-ray photon interacts with an outer shell electron which displaces the electron
2. The X-ray photon loses some of its energy (but not all) in this process
2. The scattered photon could then cause other scattering or absorption effect


How does X-ray cause direct DNA damage?

1. The DNA or RNA in the chromosomes take a direct hit from the X-ray photon which ionises and breaks the bonds between the nucleic acids (point mutation).
2. Subsequent chromosomal effect include:
a) Cell death
b) Abnormal replication
c) Failure of transference of information
d) DNA is successfully repaired before further cell division
3. If somatic cells are affected > radiation induced malignancy
4. If genetic cells are affected > congenital abnormality


How does X-ray cause indirect DNA damage?

1. X-ray photon ionises the water molecule producing ions and free radicals which can combine to form toxic substances which damage the DNA
2. Two of the free radicals produced are
a) Hydrogen peroxide
b) Hydroperoxyl radical


What are some of the tissue reaction associated with high levels of X-ray exposure?

1. Erythema of the skin
2. Hair loss
3. Reduction in bone marrow cell production
4. Cataract formation in the eye (lowest threshold dose)
5. Radiation sickness (nausea)
*each reaction has a different threshold dose (below which none of these reaction occur)


Distinguish absorbed/ equivalent/ effective dose of radiation

A) Absorbed
1. Energy absorbed per unit mass
2. Measured in gray (Gy)
B) Equivalent
1. Absorbed dose x weighting factor
2. The weighting factor for X-ray is 1
3. Measured in sievert (Sv)
C) Effective
1. Weighted sum of equivalent doses to different organs
2. Measured in sievert


What are the effective radiation dose from intra oral and panoramic radiograph?

1. Intra oral: 0.3-21.6 microSv
2. Panoramic: 2.7-38 microSv


State the ALARA principle

The likelihood of incurring exposure, the number of people exposed and the magnitude of their individual doses should all be kept as low as reasonable achievable taking into account economic and societal factors


What is the appropriate operating potential for X-ray sets?

1. Intra oral: 60-70 kV
2. Panoramic and cephalometric: 60-90 kV


What is the appropriate amount of filtration, collimation and FSD for X-ray sets?

A) Filtration
1. For X-ray tubes up to and including 70kV: 1.5mm aluminium
2. For X-ray tubes above 70kV: 2.5mm
B) Collimation
1. The beam diameter at the end of the collimator should not exceed 60mm
2. A 4x3cm rectangular collimation gives 50% dose reduction
1. For X-ray tubes operating at 60kV and above: 200mm
2. For X-ray tubes operating below 60kV: 100mm


What are the strategy for patient dose limitation in intra oral and panoramic radiography?

A) Intraoral
1. At least 60kV (ideally 65-70kV)
2. 200mm focus-skin-distance
3. Rectangular collimation
4. F speed film or properly calibrated digital system
5. Adjust exposure factors according to the patient
B) Panoramic
1. Field size limitation
2. Fast film/screen combination or properly calibrated digital system
3. Adjust exposure factors according to the patient


What are the strategy for patient dose limitation in cone beam CT?

1. Reduce exposure factors according to patient size
2. Use the smallest filed of view consistent with the diagnostic task
3. Avoid high resolution option unless absolutely necessary
4. Use thyroid shield


What are the factors that affect diagnostic yield of a radiographic image?

1. Radiographic technique: geometric accuracy of the image (film and digital)
2. Exposure factors and chemical processing (film)
3. Accruals of the digital imaging system and computer software (digital)
4. Interpretation of the final image


What are the principles of image formation in panoramic radiography?

1. The image receptor is exposed bit by bit through out the movement as the vertical beam traverses across
2. The image produced is magnified by X1.3


What are the six requirements in a radiographic quality assurance program?

A) Personnel and training
1. Training must be reviewed every 5 years
B) Working procedure
1. Local rules
2. Employer's written procedures
3. Operational procedure
C) X-ray generating equipment and patient dose
1. Maintain an equipment log/inventory
2. Obtain critical examination report and carry out acceptance test
3. Carry out routine safety test at least every 3 years
4. Carry out daily, weekly and six monthly checks
D) Image acquisition and processing
1. Proper storage, handling and use of X-ray films (before expiry date)
2. Proper cleaning and maintenance of cassettes
3. Proper chemical processing which includes
a) Light tightness
b) Safe lights: ideally 25 watts with a distance of 1.2m from work surface
c) Correct type of filter which is in good condition (coin test)
d) Processing conditions, appropriate change of chemicals (lead wedge phantom) and cleaning instruction
E) Image quality
1. Images taken must be subjectively rated
F. Audit
1. Results from an audit should be analysed to enable comparison with published targets
3. A record should be made of each analysis and the action taken


What are the aspects of a radiographic image quality rating?

1. Patient preparation (film and digital)
2. Patient positioning (film and digital)
3. Exposure (film)
4. Processing (film)
5. Film/ receptor handling (film and digital)

*1: no errors
*2: some errors but do not detract from diagnostic utility of the image
*3: errors which render the image diagnostically unacceptable


How do we achieve the ALARA principle?

1. Dose limitation by choice of equipment, film etc
2. Use of selection criteria to ensure all exposures are justified
3. Ensuring all X-ray exposures lead to optimal quality images so patient get the most benefit


What are indicators for panoramic radiography at 11-12 years of age?

1. Infra occlusion of primary molars
2. Clinically missing permanent incisors
3. Unerupted premolars after exfoliation of primary predecessor
4. Unpalpable, unerupted maxillary canine


What is the radiographic interval for the diagnosis of caries in children?

1. High risk: 6 months
2. Medium risk: 12 months
3. Low risk: 12-18 months


What is the radiographic interval for the diagnosis of caries in adults?

1. High risk: 6 months
2. Medium risk: 12 months
3. Low risk: 24 months


When should radiographs be taken for periodontal disease?

1. Horizontal bitewing for BPE code 3 with minimal gingival recession
2. Vertical bitewing for BPE code 4 or * with significant gingival recession
3. However periapical views could be supplemental as they are regarded as the gold standard in measuring crystal bone levels


What are the radiographic recommendation for endodontics?

1. A good quality pre-operative radiograph for diagnosis
2. At least one good radiograph to confirm working length unless there is confidence about WL derived from apex locator
3. If there are doubts, a mid-fill radiograph should be taken to confirm position of root filling
4. A post-operative radiograph to assess the success of obturation and to act as a baseline for assessment of apical pathology
5. A further follow-up radiograph taken at one year after completion of treatment


What are the guidelines on the use of radiographs in implant dentistry?

1. Initial examination of sites should use intra oral or panoramic radiograph
2. Where cross sectional imaging for specific region is needed, CBCT should be used


What are the guidelines on the use of radiographs prior to extractions?

1. There is no convincing evidence to support routine radiography prior to extraction in adults
2. However it is indicated in the following situations
a) History of previous difficult extraction
b) A clinical suspicion of unusual anatomy
c) A medical history placing the patient at risk if complications were encountered
d) Prior to orthodontic extraction
e) Extraction of teeth or roots that are impacted, buried or likely to have a close relationship with anatomical structures


What are the selection criteria for panoramic radiography?

1. Where a bony lesion or unerupted tooth is of a size or position that precludes its complete demonstration on Intraoral radiographs
2. In patient with grossly neglected dentition for whom there is clinically determined likelihood of multiple extraction being required
3. For the assessment of third molars prior to planned surgical intervention (routine radiography is not recommended)
4. As part of orthodontic assessment where there is a clinical need to know the state of the dentition and presence/absence of teeth (not for routine screening)
*panoramic radiography should only be taken in the presence of specific clinical signs and symptoms


What are the indication for acrylic denture?

1. Interim denture is required before definitive treatment plan can be formulated
2. The remaining teeth have a poor prognosis and their extraction and subsequent addition to the denture is anticipated
3. An immediate denture replacing anterior teeth
*never a permanent solution in the lower arch


What are the risk factors important in predicting alveolar bone loss?

1. Smoking
2. Diabetes diagnosis
3. Pocket depth
4. Bleeding on probing
5. Restoration below the gingival margin
6. Root calculus
7. Furcation involvement
8. Vertical bone lesion