ORAL SURGERY

Question 1

What are the doses in mg/kg:
- Lignocaine 2% - Plain + Adrenaline
- Articaine 4% = Plain + Adrenaline
- Prilocaine 3% - Plain + Felypressin
- Mepivacaine 3% Plain

Answer 1

Lignocaine / Articaine
- Adrenaline = 7mg/kg
- Plain = 4mg/kg

Prilocaine
- Felypressin = 9mg/kg
- Plain = 4mg/kg

Mepivacaine = 6.6mg/kg

Question 2

Which of the following is false?
(A) Mepivacaine is contraindicated for children < 4 years
(B) Ropivacaine has the highest risk of cardiotoxicity
(C) Articaine contraindicated in pregnant women
(D) Prilocaine has risk of methaemoglobinaemia

Answer 2

(B) Bupivacaine has highest risk of cardiotoxicity

Question 3

Explain the LA in xylocaine cream and EMLA cream

Answer 3

Xylocaine cream = 5% lignocaine

EMLA = 2.5% lignocaine and 2.5% prilocaine

Question 4

What the contents within the pterygomandibular space and describe the surrounding structures (medial, superior, inferior, lateral, anterior and posterior)

Answer 4

Contents:
o Inferior alveolar nerve
o Inferior alveolar artery
o Pterygoid venus plexus, inferior alveolar veins
o Sphenomandibular ligament

Surrounding structures:
o Lower head lateral pterygoid, superiorly
o Medial pterygoid, medially
o Ascending ramus, laterally
o Buccinator and superior constrictor muscle (with pterygomandibular raphe), anteriorly
o Parotid gland and its fascia, posteriorly

Question 5

What is the formal definition of MRONJ (3 criteria)?

Answer 5

 1. Current or previous treatment with anti-resorptive or anti-angiogenic agents
 2. Exposed bone or bone that can be probed through an intra-oral or extra-oral fistula(e) in the maxillofacial region that has persisted for more than eight weeks
 3. No history of radiation therapy to the jaws or obvious metastatic disease to the jaws

Question 6

Which of the following is true?
(A) Alendronic acid is an antiangiogenic medication
(B) The effects of denosumab are irreversible
(C) The risk of MRONJ for alendronic acid is not related to length of time used
(D) Denosumab is a RANKL inhibitor

Answer 6

(D)

(A) It is a bisphosphonate
(B) They are reversible after 6 months (biannual injection)
(C) Risk time related - accumulates within bone >5 years use

Question 7

List five factors that indicate high risk case for OAC.

Answer 7

o Close proximity to antral floor
o Lone standing maxillary molars
o Pneumatised sinus
o Age
o Hypercementosis
o Ankylosis
o Traumatic extractions
o Periapical pathology

Question 8

In relation to a fractured root tip, which of the following is the most correct in terms of management?
(A) Safely leave fragment >5mm after informing patient
(B) Extend root pick through centre of socket to elevate fragment
(C) Use open window technique for fragment associated with pathology
(D) Trim fragment above alveolar bone with bone file and suture over

Answer 8

(C)

Question 9

After extraction of 38 five days ago, a patient returns to your clinic with the following signs/symptoms: extraoral swelling in the area, pain/tenderness and bleeding from the socket. Which of the following has most likely occurred?
(A) Alveolar osteitis
(B) Normal process of healing
(C) Infection
(D) Reactionary bleeding

Answer 9

(C) Often occurs 5 - 7 days post-operatively. S+S include:
 Swelling increasing 3 – 5 days post procedure
 Systemic signs of infection
 Difficulty swallowing
 Suppuration or bleeding from socket

Question 10

Chromic gut is a suturing material that is:
(A) Resorbable monofilament
(B) Resorbable braided
(C) Non resorbable monofilament
(D) Non resorbable braided

Answer 10

(A)

Question 11

Which of the following is the most correct indication for removal of a wisdom tooth?
(A) Significant plaque formation around the tooth
(B) An episode of pericoronitis
(C) Impacted with unrestorable caries
(D) Patient difficulty in brushing the area

Answer 11

(C)

(A) Risk factor but NOT indication for removal
(B) ONLY second or subsequent episodes of pericoronitis should be considered appropriate indication for surgery
(D) Refer to A) - would be a risk factor rather than indication

Question 12

Name five indications of a difficult extraction.

Answer 12

 Divergent/curved roots
 Retained roots
 Teeth with endodontic therapy
 Root caries/Subgingival restorations
 Bulbous roots or hypercementosis
 Impacted or unerupted teeth
 Close proximity to maxillary sinus
 Evidence of attrition due to grinding
 Isolated maxillary molars
 Ankylosed teeth
 Associated pathology

Question 13

What is the post-operative analgesic recommendation after an extraction? (Provide drug and dose)

Answer 13

 Paracetamol 1000mg PO QID +
 Ibuprofen 400mg PO QID, five days

Question 14

Distinguish acute and chronic sinusitis

Answer 14

• Acute sinusitis: Oxygen partial pressure is high which supports growth of aerobes

• Chronic sinusitis: Inability of maxillary sinus to drain – low oxygen partial pressure which supports growth of anaerobes

Question 15

Name three common S+S of odontogenic sinusitis

Answer 15

 Unilateral
 Facial pain or pressure
 Postnasal drip
 Nasal congestion
 Foul smell or taste
 Fatigue

Question 16

After extraction of 26, you notice an OAC of 3mm in size. What is most correct in terms of its management?
(A) No treatment, it is small and therefore heals spontaneously
(B) Placement of clot-promoting agent and suture
(C) Repair with surgical procedures
(D) Prescribe antibiotics and referral to specialist

Answer 16

(B) Relevant for 2-6mm OAC

Question 17

What is an OAF and how does it form?

Answer 17

• OAF: Communication between the oral cavity and the maxillary sinus lined by epithelium
• Mechanism: migration of oral epithelium into defect resulting in a permanent epithelialized trat between maxillary sinus and oral cavity
• Persistent communication → Allergens and bacteria cause inflammation of Schneiderian membrane → Obstruction of maxillary sinus ostia (no drainage of sinus) → Concurrent bone loss due to chronic infection

Question 18

Briefly explain management of OAF.

Answer 18

1. Treat sinusitis - antibiotics and nasal decongestants
2. Surgery to repair defect –> Excise epithelial lined fistula
3. Closure over sound bone margins

Question 19

Which of the following is incorrect in regard to surgical techniques to repair OAF?
(A) Buccal advancement flap is the most common technique used
(B) Buccal fat pad advancement reduces post-operative pain and swelling
(C) Palatal rotation flap preserves buccal vestibule
(D) Buccal advancement flap decreases buccal sulcus depth

Answer 19

(B) Buccal fat pad advancement increases post-op pain and swelling

Question 20

Which of the following is correct in regard to biopsy techniques?
(A) Brush biopsy advantageous in detecting abnormalities in epithelium and submucosa
(B) Punch biopsy indicated for areas where tissue is bound down
(C) Incisional biopsy removes entire lesion including surrounding margin of normal tissue
(D) Fine needle aspiration biopsy has low specificity and sensitivity

Answer 20

(B)

Question 21

Briefly explain the methods involved in alveoplasty/alveolectomy.

Answer 21

Technique aims to smooth or recontour alveolar bone – performed at time of or post-extraction

• Incision on alveolar rest and envelope flap raised
• Bony contouring – bone files, rongeurs, surgical or acrylic burs
• Palpation to determine uniformity
• Suture

Question 22

Explain the role of mylohyoid insertion in relation to root apex of infected tooth in determining submandibular or sublingual spread of infection.

Answer 22

• Roots above mylohyoid insertion = Sublingual abscess/swelling
• Roots below mylohyoid insertion = Submandibular infection

Question 23

Which of the following is incorrect?
(A) Generally unable to palpate inferior border of mandible in submandibular space infection
(B) Sublingual space infection results in intra and extraoral swelling
(C) Ludwig’s angina involves infection in sublingual, submental and submandibular spaces
(D) Severe trismus generally indication of submasseteric spread of infection

Answer 23

(B) Nil extraoral swelling

Question 24

A patient presents to your clinic in pain with facial swelling. What 5 factors would cause you to consider management of the patient as an outpatient?

Answer 24

o Compromised defences
o Rapid, progressive infection
o Secondary fascial space involvement
o Temp over 101G
o Severe trismus <10mm
o Toxic appearance
o Difficulty swallowing or speaking
o Difficulty breathing

Question 25

A patient presents to your clinic with a history of pain in posterior region of Q4 for the past 1-2 weeks which has worsened. The patient has nil facial swelling but severe trismus and acute tenderness on extraoral palpation. on clinical examination, you conclude with the diagnosis of pericoronitis of the 48. What spread of infection is most likely?
(A) Buccal
(B) Submasseteric
(C) Submandibular
(D) Sublingual

Answer 25

(B) Often associated with pericoronitis with symptoms of severe trismus, nil swelling (may appear clinically normal) and tenderness on palpation

Question 26

You are running 1 hour late for your 4pm appointment with a patient who requires two wisdom teeth extractions. After getting the patient into the chair and administering LA, the patient stops you midway and tells you that they feel light-headed, have shortness of breath and feel a tingling sensation in their fingers/toes. What medical emergency is this most likely to be?
(A) Allergic reaction
(B) Hypoglycaemia
(C) Angina/MI
(D) Hyperventilation

Answer 26

(D)

Question 27

Explain the key factor that influences these characteristics of LA:
- Onset time
- Duration
- Potency

Answer 27

Onset time = pkA
Higher pkA = Less likely to dissociated (RNH+ > RN + H+) → Slow onset of duration
Lower pkA = Increased dissociation (RNH+ < RN + H+) → Fast onset of duration
Inflamed tissue = ↑H+ = RNH+ > RN + H+ → Slow onset of duration
Duration of LA = Protein binding
↑ Protein binding = ↑ Attaction to receptor sites to remain in sodium channels
Bupivacaine is 95% bounded to protein = Longest duration of action
Potency = Lipid solubility
↑ Lipophillic LA = ↑ Intracellular penetration into nerve cell for greater potency
Bupivacaine = x 10 more lipid soluble than lignocaine and therefore more potent

Question 28

Why is the LA dose for children much lower and potent LA such as bupivacaine contraindicated?

Answer 28

• Low AAG levels = Higher levels of unbound LA and therefore toxicity
• Loose fascial attachments = Increased potential for spread of LA
• Incomplete myelination of nerves = Low dose can easily penetrate nerve fibres

Question 29

Trauma management - explain primary and secondary survey.

Answer 29

PRIMARY SURVEY - ABCDEs
o A Airway with C-spine immobilisation
 Check for active bleeding, foreign objects compromising the airway
 LEMON rule
• Look
• Evaluation
• Mallampati
• Obstruction
• Neck movement

o B Breathing &Ventilation:
 Look, listen & feel, chest wall rising evenly, respiratory rate, oxygen saturation

o C Circulation & Hemorrhage control:
 Check capillary refill time, hypotension, tachypnoea, tachycardia,
 Look for cool extremities and sweating
 Evidence of severe bleeding (scalp, epistaxis, intra-oral sites)
 Shock
• Tachycardia
• Cool clammy skin
• Bluish tinge to lips or fingernails
• Enlarged pupils
• Fatigue
• Rapid breathing
 Fluid replacement required ~ 2.5L

o D Disability:
 Ocular assessment > pupil size, reactivity to light, symmetry
 Glasgow Coma Scale (GCS)
• Minimum score of 3
 Gross motor function

o E Exposure:
 Foreign objects should be removed for thorough assessment i.e. dentures/ mouthguard
 Cover patient to prevent hypothermia

SECONDARY SURVEY
o Good history (AMPLE)
 Allergies
 Medications
 Pregnancy/Previous illness
 Last meal
 Events leading to trauma

o Other:
 Tetanus prophylaxis > booster?
 Alcohol status?

o As a general rule:
 Look for asymmetries (challenging with oedema)
 Look for crepitus, mobility, step deformities or discontinuity
 Look for penetrated foreign objects – glass, concrete, dirt
 Look for abrasions and lacerations
 Look for tenderness on palpation
 Bruising can indicate possible underlying fracture
 Any obvious neurological deficits CN, V, VII and III, IV, VI.

o Follow a systematic approach – superior to inferior to assess all areas of the face

Question 30

Regarding parathyroid gland, related disorders and relevance to dentistry, which of the following is correct?
(A) Parathyroid gland decreases blood calcium levels
(B) Brown tumour of hyperparathyroidism appears as large radiopacities with radiolucent rim
(C) MRONJ should be assessed in hyperparathyroidism due to patients being on antiangiogenic medications
(D) NSAIDs should be avoided in hyperparathyroidism due to renal disease/peptic ulceration

Answer 30

(D)

(A) PTH increases calcium levels
(B) BTH is large moth eaten radiolucency
(D) MRONJ should be assessed but due to use of antiresorptives in patients

Question 31

Which of the following is correct management of endocrine disorder?
(A) Avoid LA with adrenal in hyperparathyroidism
(B) Nil changes in management for adrenal insufficiency if surgery <1hr
(C) In uncontrolled diabetics, all appointments should be delayed with referral to GP for BSL to be under control
(D) GA over conscious sedation is preferred in hyperthyroidism

Answer 31

(B)

(A) LA is safe
(C) Symptomatic treatment should still be carried out with post-op abx if ifnection and then referral to GP
(D) Avoid GA if possible due to risk of arrhythmia. Conscious sedation is safe.

Question 32

Explain function of thyroid hormones and S+S in hyperthyroidism

Answer 32

Function of thyroid hormones:
- Heat production
- Metabolic turnover of glucose, fat, protein
- Sympathomimetic effects (increased cell sensitivity to adrenaline) → Increase HR and peripheral vasodilation

S+S
• Weight loss
• Heat intolerance and excessive sweating
• Tachycardia (anxious)
• Increased appetite
• Exophthalmos/proptosis (Grave’s disease)

Question 33

What are the additional agents contained in LA?

Answer 33

1. Buffering agents → Sodium hydroxide, hydrochloric acid and EDTA
   Adjust pH to 3.5 – 5 (stabilise adrenaline)
   pH of plain solutions adjusted to between 4-7
2. Antioxidant/Preservative (per TGA always included w/ adrenaline) → Sodium metabisulfite
   Prevents oxidation of vasoconstrictor and lowers pH
3. Vasoconstrictors (adrenaline and felypressin) → Slow local absorption of drug to reduce toxicity and increase duration of action.

Question 34

Why do we use less LA in children?

Answer 34

 Low α-1 acid glycoprotein (AAG) resulting in higher levels of unbound LA and toxicity (LA preferentially binds to AAG)
 Incomplete myelination allows better penetration of LA into nerve fibres
 Loose fascial attachments facilitate spread of LA

Question 35

Name common areas of inadvertent LA spread for IAN and PSA block.

Answer 35

IAN block → Infratemporal fossa, parotid gland (facial nerve anaesthesia)
PSA block → Infratemporal fossa, pterygopalatine fossa (ocular complications)

Question 36

Signs and symptoms of LA overdose?

Answer 36

S+S: CNS then CVS effects
1st = CNS effects
Visual and aural disturbances
Tremors
Dizziness
Convulsions and seizures
Severe = Coma and respiratory arrest
2nd = CVS effects
↓ Myocardial contractility
↓ Heart rate
Hypotension
Arrythmias
Death

Question 37

How does surgicel, gelatemp, gelfoam and tranexamic acid work? Briefly explain directions.

Answer 37

1. Surgicel = Cellulose –> Absorbs blood in cavity to stabilise blood clot
   > Placed inside cavity and resrobs in ~8wks, avoid placing near IAN (can cause nerve damage)
2. Gelatamp = Gelatine sponge w/ colloidal silver –> Sponge absorbs the blood to stabilsie clot and colloidal silver has antibacterial properties
   > Placed inside cavity and resorbs in ~4-6wks
3. Gelfoam = Gelatine sponge - see above
4. Tranexamic acid = inhibits plasminogen which activates plasmin to break down fibrin (clot stabiliser)
   > Able to apply onto gauze over clot
   > Homecare: 4.8% mouthrinse 10mL - 4x/day for 2 days
   > TGA advised evidence for warfarin patients - no evidence for NOACs

Question 38

Indications of difficult extraction?

Answer 38

 Divergent/curved roots
 Retained roots
 Teeth with endodontic therapy
 Root caries/Subgingival restorations
 Bulbous roots or hypercementosis
 Impacted or unerupted teeth
 Close proximity to maxillary sinus
 Evidence of attrition due to grinding
 Isolated maxillary molars
 Ankylosed teeth
 Associated pathology

Question 39

What is key in designing a surgical flap in terms of surgical margins?

Answer 39

Base should always be wider than the surgical margin - corner of surgical margin is still able to receive blood supply from the periosteum and collateral vessels that are still intact

Question 40

What are the borders of the maxillary sinus?

Answer 40

Inferiorly – alveolar bone of the maxilla and maxillary teeth
Laterally the apex points towards the zygoma
Medially the body forms the lateral wall of the nose
Superiorly forms the floor of the orbit → Infraorbital canal usually runs through the roof of the sinus
Posteriorly – wall of the maxilla that borders the pterygomaxillary fissure

Question 41

Common sign and symptoms of odontogenic sinusitis?

Answer 41

 Unilateral
 Facial pain or pressure
 Postnasal drip
 Nasal congestion
 Foul smell or taste
 Fatigue

Question 42

What advice provided to patients for sinus precautions?

Answer 42

Avoid:
- Flying/diving
- Blowing nose too hard
- Sucking straws
- Sneezing

Question 43

Distinguish cellulitis and abscess?

Answer 43

o Cellulitis
 Tissue inflammation
 No collection of pus
 Diffuse/indurated (hard)
 SYSTEMIC SYMPTOMS
o Abscess = Local collection of pus
 Fluctuant (movable and compressible)
o Generally, occur together

Question 44

Distinguish Le Fort I, II, III and panfacial fractures

Answer 44

o Le fort I ‘floating maxilla’
 Upper lip swelling
 Anterior open bite
 Ecchymosis of buccal vestibule and palatal mucosa
 Epistaxis
o Le fort II:
 Le fort I features +
 Classic ‘racoon’ facies (bilateral periorbital oedema & ecchymosis)
 Cerebrospinal fluid leak from nasal cavity – concern due to risk of meningitis
 Sensory changes of the infraorbital nerve
 Malocclusion
 Facial lengthening & widening
 Subconjunctival hemorrhage (bleed behind conjunctiva)
o Le fort III:
 Le fort II features +
 Dish face deformity (flattening of the face)
 Ecchymosis over the mastoid region
o Panfacial fractures: fractures involving all thirds of the face
 Fractures of lower face, mid face and the upper face.

Question 45

Explain pathophysiology of adrenal crisis

Answer 45

Adrenal crisis = Occurs in patients with adrenal insufficiency –> deficiency in corticosteroids (= glucocorticoids and mineralcorticosteroids)

1. Deficiency glucocorticoids
   - Liver function decreases → Hypoglycaemia → Loss of consciousness and shock
   - Nausea and vomiting (unknown mechanism)
2. Deficiency mineralcorticosteroids
   Lack of aldosterone → Hypovolaemia → Low BV and BP = Shock and cardiac arrest

Question 46

What are the four types of suturing materials?

Answer 46

Monofilament
- Resorbable = Chromic gut
-Non resorbable = Nylon

Braided
- Resorbable = Vicryl
- Non resorbable = Silk

Question 47

What are the 7 radiographic signs that indicate IAN is in close proximity to the roots?

Answer 47

• 1. Root darkening
• 2. Deflection of root
• 3. Narrowing of the root
• 4. Dark and bifid apex of the root
• 5. Deviation of canal
• 6. Interruption of sclerotic margins of canal
• 7. Narrowing of cana

Question 48

Signs and symptoms of odontogenic sinusitis?

Answer 48

 Unilateral
 Facial pain or pressure
 Postnasal drip
 Nasal congestion
 Foul smell or taste
 Fatigue

Question 49

What are goals of preprosthetic surgery?

Answer 49

o 1. Provide a bony foundation for the prosthesis
o 2. Eliminate hard and soft tissue pathology
o 3. Provide proper interarch relationships
o 4. Achieve properly contoured alveolar ridges (tall, broad, U-shaped)
o 5. Eliminate bony and soft tissue undercuts and protuberances
o 6. Ensure adequate keratinized attached gingiva in denture-bearing areas
o 7. Ensure adequate vestibular depth
o 8. Plan for possible implants

Question 50

What are the four surgical flaps? Briefly explain indications

Answer 50

1. Envelope flap = Simple, less traumatic, used for single tooth (anterior - not much access required)
2. Mucoperiosteal flap w/ one relieving incision = Require greater access
3. Mucoperiosteal flap w/ two relieving incisions = Rare - Multiple teeth, posterior, requiring significant access
4. Semilunar flap = Limited access, requiring access to apical roots only

Question 51

How do you manage a dry socket? How long do you expect healing to occur?

Answer 51

1. Irrigate with saline and chx
2. Gently pack alvogyl into area
3. Prescribe analgesia management
4. Review patient after 2-3 days
   (Generally 4 weeks for healing)

Question 52

Explain S+S of:
a) Lateral pharyngeal infection spread
b) Ludwig’s angina

Answer 52

a) - Difficulty swallowing -> Drooling
- Swelling at the neck
- Systemic signs
- Uvula deviated to one side
b) - Brawny swelling bilaterally - involves submandibular, sublingual and submental space
- Swelling in FOM –> Tongue protrusion
- Difficulty swallowing, speaking, breathing
- Erythema of skin

Question 53

What is Cushing’s Syndrome and what S+S expected?

Answer 53

Excess glucocorticoids (cortisol) –> Increased lipolysis, decreased protein synthesis and glucose uptake
S+S:
- Diabetes
- Hypertension
- Obesity
- Immune suppression
- Striae of skin

Question 54

What four options are available for reconstructive surgery?

Answer 54

1. Primary closure
2. Grafting
3. Flap techniques
4. Non biological materials

Question 55

Describe the passage of lingual nerve

Answer 55

Branch of mandibular nerve (V/3)
- Arises with the IAN but passes anteromedial to the IAN
- Passes between MPM and ramus of the mandible
- Advances anteromedially deep to mylohyoid and lateral to hyoglossus to insert into the tongue
(Superior to the submandibular gland)

Question 56

Explain mechanism of vasovagal syncope

Answer 56

• Patient is anxious/scared –> SNS activated with increase in HR and release of adrenaline which causes vasoconstriction
• Underfilled left ventricle triggers mechanoreceptors in heart for vagal activation and decrease in sympathetic drive –> Bradycardia and vasodilation (hypotension)
• Decrease in cerebral blood flow = Loss of consciousness

Question 57

What are common side effects of cardiac drugs?

Answer 57

CCBs –> Gingival hyperplasia
Antihypertensives –> Diuretics and ACEI
- Dehydration = Hyposalivation
- Avoid use with NSAIDS
- Orthostatic hypotension

Question 58

Explain the actions of corticosteroids

Answer 58

Glucocorticoids (cortisol)
- Released in response to stress
- Anti-insulin effects = Increases blood glucose, decreases protein synthesis and increases lipolysis
- Immunosuppression
- Increased PTH levels = Bone resorption
- Vasoconstriction = Hypertension

Mineralocorticoids (aldosterone)
- Decreased in salt retention = Hypertension

Question 59

Briefly explain the process of haemostasis

Answer 59

1. Primary haemostasis
   - Reflective vasoconstriction with endothelin released by endothelial cells
   - Adhesion: Vwf released by damaged endothelial cells which bind to GP1B protein on platelets
   - Activation: Triggers platelet shape change and activation –> Thromboxane A2 released which combines with ADP to result in GP2B expression on platelet = Aggregation (binds with fibrin)
2. Secondary haemostasis
   - Extrinsic pathway = Fast, triggered by tissue factor that activates F7 when bound together with calcium
   > F7a + TF + Ca = Complex into common pathway
   - Intrinsic pathway = Slow, triggered by exposed collagen in endothelium
   > F12 activated through binding to collagen and phosphates on platelets –> Cascade of F11 and F9 activation
   > F9a + F8a + Ca = Complex into common pathway
3. Common pathway
   - Complexes activate F10 which activates F5
   - F10a + F5a = Prothrombinase complex –> Activates F2 to F2a
   - F1 to F1a activated
   - Thrombin = Platelet aggregation, activates F13a to form fibrin meshwork with fibrin (clot stabilisation), activates F8, F9 and F5 as well