I85PREP
⌘ K
Kuwait Dental Board Oral & Maxillofacial Surgery study materials
Kuwait Dental Board Oral & Maxillofacial Surgery study resources

Kuwait Dental Board Oral & Maxillofacial Surgery practice questions

One question at a time. Build your Kuwait Dental Board Oral & Maxillofacial Surgery understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

During surgical removal of a lower third molar, the inferior alveolar nerve is at greatest risk of injury in which anatomical location?

  1. Within the infratemporal fossa before entering the mandibular foramen
  2. Within the pterygomandibular space medial to the medial pterygoid muscle
  3. As it emerges from the mental foramen on the buccal surface of the mandible
  4. Where the nerve passes close to the apices of the third molar in the mandibular canal Correct answer.

Explanation

The inferior alveolar nerve runs in the mandibular canal, and its closest relationship to the third molar roots is at the apex region, where the canal may lie within a few millimetres of the root tips. Preoperative radiographic assessment of this proximity predicts neurosensory risk.

Question 2Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

A patient on warfarin requires extraction of a periodontally involved tooth. Which preoperative laboratory value best guides safe management?

  1. Activated partial thromboplastin time
  2. Bleeding time
  3. Platelet count
  4. International normalized ratio Correct answer.

Explanation

Warfarin inhibits vitamin K–dependent clotting factors and is monitored by the international normalized ratio, which reflects the extrinsic pathway. Local haemostatic measures are usually sufficient for minor oral surgery when the INR is within the therapeutic range.

Question 3Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which cranial nerve provides motor innervation to the tensor veli palatini, a muscle that must be considered during palatal surgery?

  1. Mandibular division of the trigeminal nerve Correct answer.
  2. Pharyngeal branch of the vagus nerve
  3. Glossopharyngeal nerve
  4. Facial nerve

Explanation

The tensor veli palatini is supplied by the nerve to the medial pterygoid, a branch of the mandibular division of the trigeminal nerve. All other palatal muscles are supplied by the pharyngeal plexus, mostly via the vagus.

Question 4Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

A patient develops a dry socket after mandibular extraction. Which physiological process is primarily impaired in this complication?

  1. Primary haemostasis by platelet plug formation
  2. Formation of granulation tissue and secondary intention healing
  3. Remineralization of the adjacent alveolar bone
  4. Fibrinolysis of the blood clot within the socket Correct answer.

Explanation

Alveolar osteitis results from premature loss or lysis of the protective blood clot, exposing bare bone. Fibrinolytic activity in the socket is believed to dissolve the clot before granulation tissue can organise.

Question 5Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which microorganism is most characteristically associated with acute necrotizing ulcerative gingivitis?

  1. Streptococcus mutans
  2. Fusobacterium species with spirochetes Correct answer.
  3. Candida albicans
  4. Actinomyces israelii

Explanation

Acute necrotizing ulcerative gingivitis is a polymicrobial infection in which fusiform bacteria and spirochetes, along with Prevotella intermedia, predominate. The punched-out interdental papillae and pseudomembrane reflect this anaerobic fusospirochetal flora.

Question 6Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which electrolyte abnormality most directly predisposes a patient to cardiac arrhythmia during oral surgery under local anaesthesia?

  1. Hyperkalaemia Correct answer.
  2. Hypochloraemia
  3. Hypercalcaemia
  4. Hyperphosphataemia

Explanation

Elevated extracellular potassium reduces the resting membrane potential difference and depresses cardiac conduction, predisposing to arrhythmias, especially with added adrenaline. Calcium and phosphate abnormalities affect excitability less acutely in this context.

Question 7Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which suture material is most appropriate when prolonged tensile strength is required in a contaminated oral wound?

  1. Polydioxanone Correct answer.
  2. Plain catgut
  3. Poliglecaprone 25
  4. Chromic catgut

Explanation

Polydioxanone is a slowly absorbed monofilament that retains strength for several weeks and provokes little tissue reaction, making it suitable where prolonged support is needed. Catgut loses strength rapidly and is more reactive.

Question 8Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

A patient with a history of penicillin anaphylaxis needs antibiotic prophylaxis before oral surgery. Which regimen is most appropriate?

  1. Amoxicillin 2 g orally one hour preoperatively
  2. Cephalexin 2 g orally one hour preoperatively
  3. Azithromycin 500 mg orally one hour preoperatively Correct answer.
  4. Clindamycin 600 mg orally one hour preoperatively

Explanation

When a genuine anaphylactic penicillin allergy exists, a non–beta-lactam alternative such as a macrolide is chosen; azithromycin is an accepted option. Cephalosporins share cross-reactivity risk and are avoided in severe immediate reactions.

Question 9Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which structure lies immediately lateral to the maxillary sinus and may be injured during a Caldwell-Luc approach?

  1. Greater palatine artery
  2. Infraorbital nerve in the infraorbital canal Correct answer.
  3. Sphenopalatine artery
  4. Nasolacrimal duct

Explanation

The infraorbital nerve runs in the roof of the maxillary sinus within the infraorbital canal and is at risk during sinus surgery. Injury produces sensory loss over the cheek and upper lip.

Question 10Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

A patient taking a monoamine oxidase inhibitor requires a local anaesthetic. Which agent is most safely avoided because of interaction risk?

  1. Articaine with adrenaline
  2. Mepivacaine plain
  3. Lidocaine with adrenaline
  4. Prilocaine with felypressin Correct answer.

Explanation

Felypressin is a vasopressin analogue, and its use with monoamine oxidase inhibitors is generally avoided because of potential hypertensive interaction. Adrenaline-containing solutions are also used cautiously, but felypressin is the classic agent to avoid in this setting.

Question 11Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which feature of a blood clot is most important for successful healing of an extraction socket?

  1. High platelet count within the clot
  2. Rapid liquefaction of the clot
  3. Presence of bacterial colonisation
  4. Stable fibrin framework protecting the socket Correct answer.

Explanation

A stable fibrin clot provides a scaffold and barrier that supports granulation tissue ingrowth and protects the socket. Clot instability or premature lysis leads to alveolar osteitis and delayed healing.

Question 12Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

A patient with chronic renal failure is scheduled for extraction. Which drug consideration is most relevant?

  1. Increased hepatic metabolism of lidocaine
  2. Reduced risk of bleeding due to uraemia
  3. Enhanced clearance of amoxicillin
  4. Accumulation of drugs excreted renally such as gentamicin Correct answer.

Explanation

Renal impairment reduces clearance of renally excreted drugs, and aminoglycosides such as gentamicin can accumulate and cause ototoxicity and nephrotoxicity. Dosing must be adjusted accordingly.

Question 13Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which nerve block is most likely to anaesthetize the buccal soft tissue adjacent to mandibular molars?

  1. Mylohyoid nerve block
  2. Long buccal nerve block Correct answer.
  3. Inferior alveolar nerve block alone
  4. Mental nerve block

Explanation

The long buccal nerve supplies the buccal gingiva and mucosa adjacent to the mandibular molars. An inferior alveolar block anaesthetizes the teeth and lingual tissues but spares this buccal region.

Question 14Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which change in the oral mucosa is most characteristic of a chronic iron deficiency anaemia?

  1. Blue-black pigmentation of the gingiva
  2. Diffuse white hyperkeratosis of the buccal mucosa
  3. Atrophic glossitis with loss of filiform papillae Correct answer.
  4. Multiple telangiectasias on the lips

Explanation

Iron deficiency anaemia classically produces atrophic glossitis, with a smooth, depapillated tongue, and may be associated with angular cheilitis. These changes reflect impaired epithelial turnover.

Question 15Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which mechanism best explains the analgesic action of non-steroidal anti-inflammatory drugs in post-extraction pain?

  1. Agonism at opioid receptors
  2. Inhibition of cyclooxygenase and prostaglandin synthesis Correct answer.
  3. Blockade of histamine H1 receptors
  4. Blockade of voltage-gated sodium channels

Explanation

NSAIDs inhibit cyclooxygenase enzymes, reducing prostaglandin synthesis in peripheral tissues and the central nervous system, which lowers pain and inflammation. This differs from local anaesthetics and opioids.

Question 16Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which finding on a panoramic radiograph most suggests a close relationship between a mandibular third molar root and the inferior alveolar canal?

  1. A wide periodontal ligament space around the crown
  2. A horizontal impaction angle
  3. Presence of a follicular space around the crown
  4. Darkening of the root where it crosses the canal Correct answer.

Explanation

Radiolucency or darkening of the root where it overlaps the canal, along with interruption of the canal's white lines, suggests the canal is superimposed or intimately related. Such signs indicate need for cone-beam imaging before surgery.

Question 17Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which cell type is the principal source of type I collagen in the periodontal ligament during healing after surgery?

  1. Endothelial cells
  2. Macrophages
  3. Osteoclasts
  4. Fibroblasts Correct answer.

Explanation

Fibroblasts are the predominant cells of the periodontal ligament and synthesise type I and type III collagen during repair. Their activity restores the ligament's fibrous attachment after surgical injury.

Question 18Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

A patient on long-term corticosteroids undergoes surgery. Which physiological concern is most relevant?

  1. Reduced risk of postoperative infection
  2. Suppression of the hypothalamic-pituitary-adrenal axis Correct answer.
  3. Enhanced wound tensile strength
  4. Increased circulating catecholamines

Explanation

Chronic exogenous corticosteroids suppress the hypothalamic-pituitary-adrenal axis, impairing the stress response to surgery and risking adrenal crisis. Supplemental steroid cover may be required.

Question 19Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which acid-base disturbance is most likely in a patient with prolonged vomiting after a general anaesthetic?

  1. Metabolic alkalosis with decreased potassium Correct answer.
  2. Metabolic acidosis with increased bicarbonate
  3. Respiratory acidosis with increased carbon dioxide
  4. Respiratory alkalosis with decreased bicarbonate

Explanation

Prolonged vomiting loses gastric hydrogen and chloride ions, producing a hypochloraemic metabolic alkalosis, often with hypokalaemia as potassium is lost in urine. Compensation involves hypoventilation.

Question 20Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which anatomical feature of the lingual nerve makes it vulnerable during surgical removal of a mandibular third molar?

  1. It lies within the mandibular canal below the roots
  2. It is enclosed within the buccinator muscle
  3. It runs close to the lingual cortex in the retromolar region Correct answer.
  4. It passes through the mental foramen

Explanation

The lingual nerve lies close to the lingual plate of the mandible in the retromolar and third molar region, often within a few millimetres of the bone surface. Lingual retraction and deep lingual flaps can therefore injure it.

Question 21Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

A patient with uncontrolled diabetes develops a rapidly spreading facial infection after extraction. Which pathophysiological factor best explains the severity?

  1. Enhanced neutrophil chemotaxis
  2. Impaired phagocytosis and microvascular perfusion Correct answer.
  3. Increased collagen synthesis
  4. Reduced bacterial virulence

Explanation

Hyperglycaemia impairs neutrophil function, chemotaxis, and phagocytosis, while microangiopathy reduces tissue perfusion and antibiotic delivery. These combined defects allow rapid spread of odontogenic infection.

Question 22Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which biochemical marker is most useful for assessing acute myocardial injury before urgent oral surgery?

  1. Troponin I Correct answer.
  2. Lactate dehydrogenase
  3. Creatine kinase MM
  4. Alkaline phosphatase

Explanation

Cardiac troponin I is highly specific for myocardial injury and rises within hours of infarction. It is preferred over older markers such as CK-MB or LDH for detecting acute myocardial damage.

Question 23Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which mechanism explains the vasoconstrictor effect of adrenaline in a local anaesthetic solution?

  1. Blockade of beta-2 adrenergic receptors
  2. Agonism at alpha-1 adrenergic receptors Correct answer.
  3. Inhibition of angiotensin-converting enzyme
  4. Direct relaxation of vascular smooth muscle

Explanation

Adrenaline stimulates alpha-1 adrenergic receptors on vascular smooth muscle, causing vasoconstriction that reduces bleeding and prolongs anaesthesia. Beta-2 effects may cause vasodilation in skeletal muscle but the net local effect is constriction.

Question 24Applied Basic Sciences (Anatomy, Physiology, Pathology, Microbiology, Pharmacology, Biochemistry)

Which feature of a cyst lining most strongly suggests an odontogenic keratocyst rather than a radicular cyst?

  1. Stratified squamous epithelium with dense inflammation
  2. Respiratory epithelium with goblet cells
  3. Granulation tissue with cholesterol clefts
  4. Parakeratinized corrugated epithelium with palisaded basal cells Correct answer.

Explanation

Odontogenic keratocysts show a thin parakeratinized corrugated epithelial lining with a palisaded, hyperchromatic basal layer and little inflammation. Radicular cysts typically show non-keratinized epithelium with heavy inflammation.

Question 25Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A 24-year-old patient attends the oral and maxillofacial clinic with a firm, non-tender swelling of the anterior maxilla. Which radiographic view is the initial investigation of choice for assessing a suspected anterior maxillary lesion?

  1. Lateral cephalometric radiograph
  2. Transcranial temporomandibular joint view
  3. Panoramic radiograph
  4. Maxillary occlusal radiograph Correct answer.

Explanation

The maxillary occlusal radiograph gives a detailed axial projection of the anterior maxilla and is ideal for localising lesions, assessing cortical expansion and detecting root resorption in this region. A panoramic film shows the area but with less detail and more superimposition of the nasal floor and incisive canal.

Question 26Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which imaging modality provides the best soft-tissue contrast for evaluating the extent of a suspected vascular malformation in the maxillofacial region?

  1. Cone beam computed tomography
  2. Magnetic resonance imaging Correct answer.
  3. Cephalometric radiography
  4. Panoramic radiography

Explanation

Magnetic resonance imaging gives superior soft-tissue contrast and multiplanar detail, allowing the extent and flow characteristics of vascular malformations to be assessed without ionising radiation. Cone beam CT is excellent for bone but provides limited soft-tissue discrimination.

Question 27Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A patient reports sharp, lancinating pain in the distribution of the mandibular division of the trigeminal nerve, triggered by chewing and light touch, with pain-free intervals. Which diagnosis fits this presentation best?

  1. Trigeminal neuralgia Correct answer.
  2. Acute pulpitis
  3. Atypical odontalgia
  4. Temporomandibular joint arthralgia

Explanation

Trigeminal neuralgia classically produces brief, electric-shock-like pain confined to a trigeminal division, provoked by innocuous stimuli and separated by pain-free periods. The history of trigger factors with complete remission between attacks is the key discriminator.

Question 28Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which clinical finding most strongly suggests that a radiolucent mandibular lesion is a simple bone cyst rather than an odontogenic keratocyst?

  1. An empty cavity at surgical exploration Correct answer.
  2. Scalloped margins extending between tooth roots
  3. Displacement of the inferior alveolar canal
  4. Internal septa dividing the cavity

Explanation

A simple bone cyst is a pseudocyst with no epithelial lining, so surgical exploration reveals an empty cavity or only a small amount of serous fluid. Odontogenic keratocysts, by contrast, have an epithelial lining and yield keratinous material.

Question 29Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which radiographic feature is most characteristic of an ameloblastoma of the posterior mandible?

  1. Multilocular soap-bubble radiolucency with root resorption Correct answer.
  2. Ground-glass bone with cotton-wool opacities
  3. Well-defined unilocular radiolucency with a sclerotic border
  4. Sun-ray periosteal reaction

Explanation

Ameloblastoma typically appears as a multilocular, soap-bubble or honeycomb radiolucency in the posterior mandible with cortical expansion and resorption of adjacent roots. The multilocular pattern reflects its locally aggressive, infiltrative growth.

Question 30Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A patient has a suspected fracture of the mandibular condyle. Which radiographic projection is most appropriate as the initial assessment?

  1. Submentovertex view
  2. Periapical radiograph of the lower molars
  3. Reverse Towne view Correct answer.
  4. Maxillary occlusal radiograph

Explanation

The reverse Towne view projects the condyles clear of the petrous temporal bone and is the standard plain view for suspected condylar fractures. It allows comparison of condylar position and neck angulation on both sides.

Question 31Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A 45-year-old patient has a well-defined unilocular radiolucency at the apex of a non-vital mandibular first molar, with loss of the lamina dura. Which diagnosis is most likely?

  1. Radicular cyst Correct answer.
  2. Ameloblastoma
  3. Odontogenic keratocyst
  4. Dentigerous cyst

Explanation

A radiolucency at the apex of a non-vital tooth with loss of the lamina dura is the classic presentation of a radicular cyst or periapical granuloma. The loss of vitality in the associated tooth is the decisive clinical link.

Question 32Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which cone beam computed tomography finding most reliably indicates that a mandibular third molar is at increased risk of inferior alveolar nerve injury during extraction?

  1. Loss of cortication of the inferior alveolar canal adjacent to the roots Correct answer.
  2. A horizontal angulation of the third molar
  3. Deep caries on the third molar
  4. A widened periodontal ligament space on the second molar

Explanation

Loss of the radiopaque cortical border of the inferior alveolar canal where it contacts the roots, together with root deflection or narrowing, indicates intimate contact and raises the risk of nerve injury. Cortical integrity is the key anatomical criterion on cone beam CT.

Question 33Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A patient presents with a diffuse, tender swelling of the submandibular region with a raised floor of the mouth. Which imaging step best identifies an obstructing sialolith before surgery?

  1. Ultrasound of the submandibular gland Correct answer.
  2. Sialography with oil-based contrast
  3. Panoramic radiograph alone
  4. Magnetic resonance imaging of the brain

Explanation

Ultrasound is the first-line, non-invasive investigation for submandibular sialolithiasis and reliably detects radio-opaque and radiolucent calculi as well as duct dilatation. It avoids contrast and ionising radiation while giving real-time duct information.

Question 34Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which feature on a panoramic radiograph most suggests that an impacted mandibular third molar has a close relationship with the inferior alveolar canal?

  1. Darkening of the root where the canal crosses
  2. A radiolucent band crossing the roots
  3. Interruption of the white line of the canal Correct answer.
  4. A superimposed radiopaque line across the crown

Explanation

Interruption of the radiopaque cortical outline of the inferior alveolar canal where it crosses the roots is a classic plain-film sign of intimate contact. Deflection or narrowing of the roots and darkening of the root also raise suspicion and usually prompt cone beam CT.

Question 35Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A 60-year-old edentulous patient has a painless, expansile radiolucency of the anterior mandible crossing the midline. Which diagnosis should be considered first?

  1. Metastatic carcinoma
  2. Ameloblastoma
  3. Central giant cell lesion Correct answer.
  4. Traumatic bone cyst

Explanation

A central giant cell lesion commonly presents in the anterior mandible of younger to middle-aged adults and frequently crosses the midline as an expansile radiolucency. Its anterior predilection and midline crossing are useful discriminators from ameloblastoma.

Question 36Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which radiographic appearance is most typical of fibrous dysplasia of the maxilla?

  1. Multilocular radiolucency with cortical expansion
  2. Ground-glass opacification blending with surrounding bone Correct answer.
  3. Well-circumscribed radiolucency with a sclerotic rim
  4. Sun-ray periosteal spiculation

Explanation

Fibrous dysplasia produces a ground-glass or orange-peel opacification in which the lesion blends imperceptibly with adjacent bone. The loss of a distinct boundary reflects replacement of medullary bone by fibro-osseous tissue.

Question 37Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A patient with a suspected malignant lesion of the posterior maxilla has a normal panoramic radiograph. Which next step is most appropriate?

  1. Repeat panoramic radiograph in one week
  2. Magnetic resonance imaging of the lumbar spine
  3. Reassure and review in one year
  4. Cone beam computed tomography of the maxilla Correct answer.

Explanation

A panoramic radiograph has limited sensitivity for early maxillary sinus and posterior maxillary disease, so a normal film does not exclude malignancy when clinical suspicion is high. Cone beam CT or CT provides the necessary bone detail and should be obtained promptly.

Question 38Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which clinical and radiographic combination best supports a diagnosis of medication-related osteonecrosis of the jaw?

  1. Radiolucent lesion at the apex of a non-vital tooth
  2. Painful swelling with a radiopaque mass in a patient on bisphosphonates
  3. Exposed bone for two weeks after a recent extraction in a healthy patient
  4. Exposed bone for more than eight weeks in a patient on bisphosphonates with no history of radiotherapy Correct answer.

Explanation

Medication-related osteonecrosis of the jaw requires exposed or probeable bone persisting beyond eight weeks in a patient with current or previous antiresorptive or antiangiogenic therapy and no history of head and neck radiotherapy. This definition distinguishes it from delayed healing and from osteoradionecrosis.

Question 39Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which imaging finding is most useful in distinguishing osteoradionecrosis from medication-related osteonecrosis of the jaw?

  1. Presence of a sequestrum
  2. Cortical thinning of the mandible
  3. Loss of the lamina dura
  4. History of radiotherapy to the head and neck Correct answer.

Explanation

The distinction between osteoradionecrosis and medication-related osteonecrosis rests primarily on the patient's history: prior high-dose head and neck radiotherapy versus antiresorptive or antiangiogenic therapy. Radiographic features such as sequestrum formation overlap substantially between the two.

Question 40Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A 30-year-old patient has a well-defined radiolucency between the roots of the mandibular lateral incisor and canine, with the adjacent teeth vital. Which diagnosis is most likely?

  1. Lateral periodontal cyst Correct answer.
  2. Radicular cyst
  3. Odontogenic keratocyst
  4. Dentigerous cyst

Explanation

A lateral periodontal cyst presents as a well-defined radiolucency on the lateral aspect of a vital tooth root, most often in the mandibular premolar or canine region. Vitality of the adjacent teeth distinguishes it from a radicular cyst.

Question 41Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which cone beam computed tomography parameter should be optimised first when planning implant placement in the posterior mandible adjacent to the inferior alveolar canal?

  1. Patient positioning only
  2. Tube current only
  3. Voxel size and field of view Correct answer.
  4. Exposure time only

Explanation

Voxel size determines spatial resolution and the field of view determines coverage; both must be selected so that the canal, ridge and adjacent structures are visualised with sufficient detail. Tube current and exposure time affect dose and noise but not the fundamental resolution of the volume.

Question 42Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A patient has a suspected odontogenic myxoma of the mandible. Which radiographic feature most characterises this lesion?

  1. Fine, straight trabeculae producing a tennis-racket appearance Correct answer.
  2. Ground-glass opacity with ill-defined borders
  3. Well-defined unilocular radiolucency with a sclerotic rim
  4. Sun-ray periosteal reaction

Explanation

Odontogenic myxoma often shows fine, straight trabeculae crossing a radiolucency, giving a tennis-racket or stepladder appearance, with cortical expansion. This trabecular pattern reflects the myxomatous matrix of the tumour.

Question 43Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

A patient presents with a rapidly enlarging, painful swelling of the mandible and paraesthesia of the lower lip. Which feature on imaging most raises concern for malignancy?

  1. A unilocular radiolucency with a sclerotic rim
  2. Generalised widening of the periodontal ligament
  3. Ill-defined margins with cortical destruction Correct answer.
  4. A well-defined corticated border

Explanation

Ill-defined margins with cortical destruction and soft-tissue extension are the cardinal imaging signs of an aggressive or malignant process. Paraesthesia of the lower lip in this setting further supports malignant infiltration of the inferior alveolar nerve.

Question 44Oral and Maxillofacial Diagnosis, Imaging and Treatment Planning

Which structure must be identified on cone beam CT before performing an apicoectomy of a maxillary first molar to avoid haemorrhage?

  1. The inferior alveolar canal
  2. The mental foramen
  3. The greater palatine canal and descending palatine vessels Correct answer.
  4. The lingual nerve in the floor of the mouth

Explanation

The greater palatine canal transmits the descending palatine vessels and nerve, and injury during palatal surgery of the posterior maxilla can cause significant haemorrhage. Identifying its position and course on cone beam CT allows safe flap design and bone removal.

Question 45Local Anesthesia, Sedation and Pain Control

A 62-year-old patient with a documented true allergy to articaine is scheduled for extraction of a maxillary first molar. Which local anesthetic is the most appropriate alternative for routine inferior or infiltration anesthesia in this patient?

  1. Prilocaine 4% plain
  2. Articaine 4% with epinephrine 1:200,000
  3. Lidocaine 2% with epinephrine 1:100,000 Correct answer.
  4. Bupivacaine 0.5% with epinephrine 1:200,000

Explanation

Lidocaine is an amide anesthetic of a different chemical structure from articaine, which is a thiophene derivative, so cross-reactivity is not expected; lidocaine with epinephrine provides reliable pulpal anesthesia for molar extraction. Bupivacaine is reserved for long-duration postoperative pain control rather than routine anesthesia, and prilocaine plain is a weaker choice for a mandibular molar.

Question 46Local Anesthesia, Sedation and Pain Control

Which nerve block is most appropriate for achieving pulpal anesthesia of the mandibular central incisor when a conventional inferior alveolar nerve block has failed?

  1. Gow-Gates technique
  2. Incisive (mental) nerve block Correct answer.
  3. Greater palatine nerve block
  4. Long buccal nerve block

Explanation

The incisive nerve block deposits anesthetic near the mental foramen and anesthetizes the incisive branch that supplies the mandibular anterior teeth, making it a targeted rescue for anterior pulpal anesthesia. Greater palatine and long buccal blocks anesthetize palatal and buccal soft tissue only, and the Gow-Gates block is an alternative for the whole mandibular quadrant rather than a targeted anterior rescue.

Question 47Local Anesthesia, Sedation and Pain Control

What is the maximum recommended dose of lidocaine with epinephrine for a healthy 70-kg adult, based on the commonly cited limit of 7 mg/kg?

  1. 245 mg
  2. 490 mg Correct answer.
  3. 70 mg
  4. 140 mg

Explanation

Multiplying 7 mg/kg by 70 kg gives 490 mg of lidocaine, which corresponds to roughly 24.5 mL of a 2% solution. This ceiling applies to healthy adults; lower limits are used for patients with hepatic impairment or those taking cimetidine or beta-blockers.

Question 48Local Anesthesia, Sedation and Pain Control

Which finding most strongly indicates that a patient has developed local anesthetic systemic toxicity rather than a simple vasovagal syncope during an inferior alveolar nerve block?

  1. Nausea with a single episode of vomiting
  2. Perioral tingling followed by tinnitus and slurred speech Correct answer.
  3. Bradycardia with pallor and cold sweat
  4. Sudden loss of consciousness with a brief tonic-clonic movement

Explanation

Local anesthetic systemic toxicity typically begins with excitatory neurologic symptoms such as perioral numbness, metallic taste, tinnitus, and slurred speech before progressing to seizures and cardiovascular collapse. Vasovagal syncope presents with bradycardia, pallor, and sweating without these sensory warning signs.

Question 49Local Anesthesia, Sedation and Pain Control

A patient reports that a previous inferior alveolar nerve block produced transient diplopia and inability to abduct the eye. Which mechanism best explains this complication?

  1. Injection into the pterygoid venous plexus with systemic spread
  2. Needle penetration into the parotid capsule with facial nerve injury
  3. Intravascular injection into the inferior alveolar artery with retrograde flow to the orbit Correct answer.
  4. Direct trauma to the lingual nerve

Explanation

During an inferior alveolar nerve block the needle tip can enter the inferior alveolar artery; if anesthetic is injected under pressure, it can travel retrogradely through the maxillary artery into the orbital vessels and reach the extraocular muscles, causing transient diplopia and ophthalmoplegia. This resolves spontaneously as the anesthetic is cleared.

Question 50Local Anesthesia, Sedation and Pain Control

Which patient factor most increases the risk of methemoglobinemia when prilocaine is used for a mandibular block?

  1. Chronic renal failure with dialysis
  2. Well-controlled type 2 diabetes
  3. Glucose-6-phosphate dehydrogenase deficiency Correct answer.
  4. A history of penicillin allergy

Explanation

Prilocaine metabolites oxidize hemoglobin, and patients with glucose-6-phosphate dehydrogenase deficiency have reduced capacity to reduce methemoglobin back to hemoglobin, so they are at higher risk. Renal failure, diabetes, and penicillin allergy do not specifically predispose to prilocaine-induced methemoglobinemia.