Cambodia Dentistry Exit Exam cheat sheet

Mandibular nerve leaves the skull through the foramen ovale; its inferior alveolar branch enters the mandibular foramen, and the mental nerve exits at the mental foramen (usually below the apices of the premolars).

The maxillary artery's middle meningeal branch passes through the foramen spinosum; the inferior alveolar artery is a branch of the maxillary artery and supplies the mandible and lower teeth.

The facial nerve exits the stylomastoid foramen and divides into temporal, zygomatic, buccal, marginal mandibular, and cervical branches within the parotid gland.

Lingual nerve lies medial to the mandibular third molar and carries chorda tympani (taste from anterior two-thirds of tongue) and general sensation from the anterior two-thirds of the tongue.

Enamel is 96% mineral by weight, acellular, and cannot regenerate; dentin is ~70% mineral with dentinal tubules, and pulp is the only soft tissue of the tooth.

Amelogenesis imperfecta affects enamel formation; dentinogenesis imperfecta affects dentin (opalescent teeth, obliterated pulp chambers) and can be associated with osteogenesis imperfecta.

The periodontium comprises gingiva, periodontal ligament, cementum, and alveolar bone; the junctional epithelium attaches to the tooth via hemidesmosomes and is the site of periodontal pocket formation.

The temporomandibular joint is a synovial, bilateral, ginglymoarthrodial joint with a fibrocartilaginous disc; the lateral pterygoid muscle inserts on the disc and condyle and initiates jaw opening.

The greater palatine foramen is located medial to the third molar, and the incisive foramen transmits the nasopalatine nerve; the pterygomandibular space is the target for the inferior alveolar nerve block.

Recurrent aphthous stomatitis: minor ulcers are <1 cm, heal in 7–14 days without scarring; major ulcers exceed 1 cm and may scar; herpetiform ulcers are multiple and small.

Oral candidiasis: pseudomembranous form wipes off leaving erythema; chronic hyperplastic form does not wipe off and requires biopsy to exclude dysplasia.

Leukoplakia is a clinical diagnosis of a white patch that cannot be characterized as any other disease; excision or biopsy is indicated for suspicious or non-homogeneous lesions.

Erythroplakia has a higher malignant transformation risk than leukoplakia; any persistent red patch warrants biopsy.

Oral squamous cell carcinoma most commonly affects the lateral border of the tongue and floor of the mouth; risk factors include tobacco, areca (betel) nut, alcohol, and HPV (especially oropharyngeal).

Odontogenic keratocyst (OKC): lined by parakeratinized stratified squamous epithelium with palisaded basal layer; high recurrence, associated with PTCH1 and nevoid basal cell carcinoma syndrome.

Ameloblastoma: benign but locally aggressive odontogenic tumor, often in the posterior mandible, with a soap-bubble radiolucency; treatment is resection with margins.

Lichen planus: Wickham striae, bilateral, T-cell mediated; erosive forms need biopsy to exclude dysplasia and can be managed with topical corticosteroids.

Pemphigus vulgaris shows intraepithelial (suprabasal) acantholysis with IgG against desmoglein; mucous membrane pemphigoid shows subepithelial separation with linear IgG/C3 at the basement membrane.

Caries removal endpoint: excavation of infected dentin until firm, leathery, or hard dentin is reached; soft dentin is removed, and affected dentin may be retained if remineralizable.

Rubber dam isolation is standard for endodontic treatment and adhesive restorations; it protects the airway and maintains a dry field.

Working length is determined by apex locator and confirmed radiographically; the apical constriction is typically 0.5–1.0 mm short of the radiographic apex.

Root canal irrigation: sodium hypochlorite (0.5–5.25%) dissolves organic tissue and is antimicrobial; EDTA removes the smear layer; chlorhexidine is an alternative when NaOCl is contraindicated but should not be mixed directly with NaOCl.

Canal preparation uses crown-down or step-back techniques; the master apical file should be 2–3 sizes larger than the first file that binds at the apex (or per contemporary rotary protocols).

Post-endodontic restoration: a post is indicated when there is insufficient coronal tooth structure; retention depends on post length (at least equal to crown height) and remaining dentin, not post material alone.

Composite bonding: etch enamel with 35–37% phosphoric acid, apply adhesive, and light-cure; dentin etching is typically simultaneous with self-etch or etch-and-rinse systems.

Endodontic flare-up: pain or swelling within 24–48 hours after treatment; incidence is reduced by complete cleaning, shaping, and not overinstrumenting beyond the apex.

Vertical root fracture: presents with a deep narrow periodontal pocket, J-shaped radiolucency, and pain on biting; extraction is usually required.

Complete denture occlusion: bilateral simultaneous contact in centric relation, balanced occlusion in excursions, and no interference on the working or balancing sides.

Posterior palatal seal provides retention and is placed at the junction of the hard and soft palate, typically 1–2 mm wide and deepest at the midline.

Vertical dimension of occlusion is assessed by resting freeway space (2–4 mm), phonetics, and facial appearance; overclosure causes angular cheilitis and reduced freeway space.

Fixed partial denture abutment selection: crown-to-root ratio ideally ≥1:1, adequate periodontal support, and alignment; cantilever use should be minimized.

Removable partial denture: rests provide support, clasps provide retention, and major connectors should be rigid and avoid impinging on gingival margins.

Occlusal scheme for implant-supported restorations should avoid non-working-side contacts; implant overload is associated with parafunction and cantilevers.

Denture stomatitis is usually Candida-associated; treatment includes denture hygiene, overnight removal, and antifungal therapy; biopsy if non-responsive.

Centric relation is the maxillomandibular relationship with the condyles in their most anterior-superior position against the articular eminences, independent of tooth contact.

Gingivitis is reversible inflammation confined to the gingiva; periodontitis involves clinical attachment loss and alveolar bone loss.

Probing depth ≥4 mm with bleeding indicates possible pocket; attachment loss is measured from the cementoenamel junction to the base of the pocket.

Periodontal disease classification (2018): staging uses severity (CAL, bone loss, tooth loss) and complexity; grading uses progression rate (bone loss/age, % bone loss, risk factors).

Scaling and root planing is the initial therapy for periodontitis; re-evaluation occurs 4–6 weeks later before considering surgery.

Risk factors: smoking, diabetes (especially HbA1c >7%), poor plaque control, and genetic predisposition; smoking reduces bleeding and masks inflammation.

Aggressive periodontitis (now stage III/IV grade C) often affects younger patients with rapid attachment loss and may involve Aggregatibacter actinomycetemcomitans.

Gingival recession treatment: root coverage procedures (connective tissue graft, coronally advanced flap) are indicated for esthetic concerns or hypersensitivity, not routinely for mild recession.

Peri-implant mucositis is reversible inflammation around an implant; peri-implantitis includes bone loss and requires surgical or nonsurgical debridement plus implant surface decontamination.

Antibiotics are adjunctive, not primary, in periodontal therapy; systemic antibiotics may be considered for aggressive or necrotizing forms after mechanical debridement.

Third molar extraction indications: recurrent pericoronitis, caries, periodontal disease, cyst/tumor, orthodontic need, and prevention of root resorption of adjacent teeth.

Inferior alveolar nerve injury risk is highest with deeply impacted mandibular third molars; radiographic signs include root proximity to the canal and narrowing of the canal.

Dry socket (alveolar osteitis) presents 2–4 days post-extraction with severe pain and exposed bone; treatment is irrigation, dressing, and analgesia, not antibiotics routinely.

Mandibular fracture: most common site is the angle, followed by the condyle and body; clinical signs include malocclusion, step deformity, and inferior alveolar nerve paresthesia.

Le Fort I fracture is a horizontal fracture above the apices of the teeth; Le Fort II is pyramidal; Le Fort III is craniofacial disjunction.

Odontogenic infection spread: submandibular, sublingual, and buccal spaces; Ludwig's angina is bilateral submandibular and sublingual cellulitis with airway compromise requiring urgent drainage and airway management.

Postoperative bleeding after extraction is managed by pressure pack, local hemostatic agents, and suturing; persistent bleeding requires evaluation for coagulopathy.

Orthognathic surgery: Le Fort I osteotomy for maxillary repositioning, bilateral sagittal split osteotomy (BSSO) for mandibular advancement or setback, and genioplasty for chin correction.

Eruption timing: primary teeth begin at 6 months; first permanent molar and mandibular central incisor erupt at ~6 years; the mixed dentition phase lasts until ~12 years.

Class I molar relationship: mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar.

Class II malocclusion: mandibular molar is distal to its Class I position; Class III: mandibular molar is mesial.

Angle's classification uses the first molars; canine relationship and incisor overjet/overbite should also be recorded.

Space maintenance: a band-and-loop or distal shoe is indicated after premature loss of a primary molar to prevent space loss; the distal shoe is used when the first permanent molar has not erupted.

Early childhood caries: affects children under 6; prevention includes fluoride varnish, dietary counseling, and parental oral hygiene; severe cases may require general anesthesia.

Fluoride varnish (5% NaF) is applied 2–4 times yearly for high-risk children; fluoride toothpaste concentration should be age-appropriate (smear for under 3, pea-sized for 3–6).

Pulpotomy in primary teeth is indicated for vital pulp exposure; pulpectomy is indicated when the radicular pulp is irreversibly inflamed or necrotic.

Habit correction: digit sucking beyond age 4 may cause anterior open bite and increased overjet; behavioral approaches and appliances are used if it persists.

DMFT index measures decayed, missing, and filled permanent teeth; dmft is used for primary teeth; DMFS counts surfaces.

Prevalence is the proportion of a population with disease at a point in time; incidence is the number of new cases over a period.

Sensitivity is the ability of a test to identify true positives; specificity identifies true negatives; predictive values depend on disease prevalence.

Community water fluoridation at 0.7–1.0 ppm reduces caries; optimal level depends on climate and water intake.

Herd immunity/protection for caries is not applicable; prevention relies on fluoride, sealants, diet, and plaque control.

Sealants are indicated for deep pits and fissures of permanent molars, especially in high-caries-risk children; they should be monitored and repaired.

Oral health surveys should use WHO criteria and calibrated examiners; kappa statistic measures inter-examiner agreement (≥0.8 is good).

Social determinants of health, including income, education, and access, influence oral health outcomes; public health programs should target high-risk groups.

Tobacco and areca nut use are major risk factors in Cambodia and the region; cessation counseling is a core prevention activity.

Local anesthetics: lidocaine 2% with 1:100,000 epinephrine provides ~60 minutes pulpal anesthesia; articaine 4% has higher lipid solubility and may be used for infiltration.

Maximum doses: lidocaine 4.4 mg/kg (without epinephrine) and 7 mg/kg with epinephrine; articaine 7 mg/kg; calculate by body weight and cartridge volume (1.8 mL).

Epinephrine contraindications are relative: severe cardiovascular disease, uncontrolled hyperthyroidism, and pheochromocytoma; use the lowest effective dose.

Antibiotics: amoxicillin is first-line for odontogenic infections; penicillin allergy: clindamycin or azithromycin; metronidazole is added for anaerobic coverage in severe infections.

Analgesics: NSAIDs (ibuprofen) are effective for dental pain; avoid in peptic ulcer, renal disease, and asthma; paracetamol is an alternative.

Antifungals: nystatin or miconazole for oral candidiasis; fluconazole for resistant or systemic cases; check for drug interactions with miconazole and warfarin.

Bisphosphonate-related osteonecrosis of the jaw (BRONJ): risk increases with intravenous and long-term oral use; avoid elective extractions if possible and obtain informed consent.

Anticoagulants: do not routinely stop warfarin for simple extractions if INR is within therapeutic range; check INR and use local hemostatic measures.

Drug interactions: erythromycin and azole antifungals inhibit CYP3A4 and can raise levels of statins, warfarin, and some antiarrhythmics; review medications before prescribing.

Inferior alveolar nerve block: target is the pterygomandibular space, with the needle directed toward the mandibular foramen; aspirate before injecting to avoid intravascular injection.

Gow-Gates and Vazirani-Akinosi are alternative mandibular block techniques; Gow-Gates targets the neck of the condyle and has a high success rate.

Maxillary infiltration: inject above the apex of the tooth; the greater palatine and nasopalatine blocks are used for palatal anesthesia.

Signs of local anesthetic toxicity: tinnitus, metallic taste, perioral numbness, seizures, and cardiovascular depression; manage with airway support and, for bupivacaine, lipid emulsion.

Syncope is the most common medical emergency in dentistry; manage by supine position, oxygen, and monitoring.

Anaphylaxis: epinephrine IM 0.3–0.5 mg (1:1000) in the anterolateral thigh, oxygen, and emergency services; antihistamines are adjunctive.

Standard precautions: hand hygiene, gloves, masks, eye protection, and safe sharps handling; sterilize instruments by autoclave at 121°C for 15–20 minutes or 134°C for 3–4 minutes.

Surface disinfection: use hospital-grade disinfectant; avoid contamination of dental unit waterlines; flush lines and follow manufacturer protocols.

Post-exposure prophylaxis for HIV: start within hours, follow national guidelines, and report; hepatitis B vaccination and post-exposure immunoglobulin are indicated for non-immune exposed staff.

History: chief complaint, duration, character, aggravating and relieving factors, and associated symptoms; use open-ended questions before focused examination.

Extraoral examination: inspect symmetry, lymph nodes, TMJ, and muscles of mastication; palpate for tenderness and crepitus.

Intraoral examination: inspect all mucosal surfaces, tongue, floor of mouth, and palate; use a systematic sequence and record lesions with size, color, and location.

Radiographic interpretation: describe radiolucency or radiopacity, margins, location, and effect on adjacent structures; correlate with clinical findings.

Pulp sensibility testing: cold test and electric pulp test assess pulp vitality; a negative response may indicate necrosis, but false negatives occur with calcification or recent trauma.

Percussion and palpation help localize apical periodontitis; mobility and probing depths assess periodontal status.

Biopsy is indicated for persistent lesions >2 weeks, suspicious white or red patches, and any lesion with induration or ulceration.

Differential diagnosis should include odontogenic, mucosal, bone, and systemic conditions; systemic diseases such as diabetes and HIV can present with oral manifestations.

Informed consent and documentation are part of diagnosis; record findings, tests, and referrals.

Treatment plan sequence: emergency care, disease control (caries, periodontal, infection), then definitive restorative, prosthetic, and surgical care.

Medical risk assessment: ASA classification; ASA III–IV patients may need medical consultation and modified treatment, especially with cardiovascular disease, diabetes, or bleeding disorders.

Informed consent must include diagnosis, treatment options, risks, benefits, and alternatives; document the discussion.

Emergency syncope: supine position, elevate legs, oxygen, monitor vital signs; if no recovery, call emergency services.

Emergency angina: stop treatment, sit upright, give nitroglycerin sublingually if prescribed, oxygen, and call for help if pain persists.

Emergency hypoglycemia: give oral glucose if conscious; if unconscious, call emergency services and do not give oral fluids.

Emergency asthma: stop treatment, sit upright, administer bronchodilator inhaler, oxygen, and call for help if severe.

Emergency hemorrhage: apply pressure, use hemostatic agents, and refer if uncontrolled; assess for anticoagulant use.

Emergency aspiration or swallowing of objects: maintain airway, refer for radiograph and retrieval if needed; prevention includes rubber dam and floss ligatures.