NMCLE Dental cheat sheet

Mandibular first molar has five cusps: mesiobuccal, distobuccal, distal, mesiolingual, distolingual; the distolingual is smallest and may be absent.

The maxillary first molar has four cusps plus the cusp of Carabelli on the mesiolingual surface; its roots are mesiobuccal, distobuccal, and palatal (lingual).

Enamel is formed by ameloblasts; these cells are lost after eruption, so enamel cannot regenerate.

Dentin is formed by odontoblasts throughout life; primary dentin forms before eruption, secondary after eruption, tertiary in response to injury.

The dental lamina gives rise to the enamel organ; the bud, cap, and bell stages describe tooth germ development.

The tongue's anterior two-thirds develops from the first branchial arch (tuberculum impar and lateral lingual swellings); the posterior third from the third arch.

The temporomandibular joint is a synovial, ginglymoarthrodial joint with a fibrocartilaginous disc; it is the only joint of the body with a fibrocartilage disc.

The inferior alveolar nerve enters the mandibular foramen and exits at the mental foramen; it supplies the mandibular teeth and chin.

The parotid gland is the largest salivary gland; its duct (Stensen's duct) opens opposite the maxillary second molar.

Recurrent aphthous stomatitis: minor ulcers are <1 cm, heal in 10–14 days without scarring; major ulcers are >1 cm and may scar.

Leukoplakia is a clinical term for a white patch that cannot be characterized as any other disease; diagnosis requires biopsy to exclude dysplasia or carcinoma.

Squamous cell carcinoma of the lip: lower lip is far more common; risk factors include sunlight, tobacco, and alcohol.

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

Ameloblastoma: benign but locally aggressive odontogenic tumor; most common in posterior mandible; radiographic soap-bubble appearance; treatment is wide resection.

Pleomorphic adenoma is the most common salivary gland tumor, usually in the parotid; it has a fibrous capsule and risk of recurrence if ruptured.

Oral lichen planus: bilateral white striae (Wickham striae) on buccal mucosa; may be erosive; potential malignant transformation (low risk).

Periapical cyst is the most common odontogenic cyst; lined by non-keratinized stratified squamous epithelium with inflammation; develops from radicular granuloma.

Herpes simplex virus type 1 causes primary herpetic gingivostomatitis and recurrent herpes labialis; reactivation triggers include stress, sunlight, and fever.

Third molar extraction: indications include pericoronitis, caries, cyst, and orthodontic need; contraindications include uncontrolled systemic disease and high risk of nerve injury.

Inferior alveolar nerve injury risk is highest with extraction of mandibular third molars with roots close to the canal; radiographic signs include darkening, interruption of canal wall, and diversion.

Ludwig's angina is a bilateral submandibular, sublingual, and submental cellulitis; airway management is priority; treat with IV antibiotics and surgical drainage.

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

Mandibular fracture: most common site is the angle, followed by the condyle; treat with closed reduction (IMF) or open reduction internal fixation (ORIF).

Dry socket (alveolar osteitis): severe pain 2–4 days post-extraction due to loss of blood clot; treat with irrigation and medicated dressing, not antibiotics routinely.

Orthognathic surgery: Le Fort I osteotomy for maxillary repositioning; bilateral sagittal split osteotomy (BSSO) for mandibular advancement or setback.

Biopsy principles: incisional for large lesions, excisional for small lesions; avoid incising through malignant tumor if possible; send specimen in formalin.

Postoperative bleeding after extraction: apply pressure with gauze, check blood pressure, consider local hemostatic agents (e.g., tranexamic acid mouthwash) if needed.

Caries removal: use slow-speed round bur or excavator; maintain enamel margins for restoration; consider caries-detector dye.

Amalgam restoration: contraindicated in anterior teeth and in patients with known allergy; use rubber dam and proper condensation.

Composite resin: etch enamel with 37% phosphoric acid for 15–30 seconds, then apply bonding agent; avoid contamination with saliva.

Root canal working length: determine with apex locator and confirm with radiograph; ideal length is 0.5–1.0 mm short of radiographic apex.

Irrigation: sodium hypochlorite (0.5–5.25%) dissolves organic tissue and disinfects; EDTA (17%) removes smear layer; avoid extrusion beyond apex.

Obturation: gutta-percha with sealer; lateral condensation or warm vertical compaction; avoid overextension.

Endodontic flare-up: pain or swelling within 48 hours; manage with drainage, occlusal adjustment, and analgesics.

Pulp capping: direct pulp cap with calcium hydroxide or MTA for small exposures; indirect pulp cap for deep caries; monitor vitality.

Nickel-titanium rotary files: used for shaping curved canals; risk of file separation; use torque-controlled motor and copious irrigation.

Complete denture: primary impression with irreversible hydrocolloid; final impression with border molding using modeling compound and light-body elastomer.

Occlusal vertical dimension (OVD) is established at rest position minus 2–4 mm freeway space.

Balanced occlusion in complete dentures: bilateral simultaneous contacts in centric occlusion, working side, and balancing side.

Fixed partial denture (bridge) abutment selection: crown-to-root ratio >1:1, adequate bone support, and alignment; splinting may be needed.

Removable partial denture (RPD): major connector (lingual bar or palatal plate) should be rigid; rests provide support; clasps provide retention.

Implant-supported prosthesis: osseointegration requires 3–6 months healing; consider bone quality and quantity; avoid premature loading.

Denture stomatitis: chronic erythematous candidiasis under denture; treat with antifungal and denture hygiene; remove dentures at night.

Try-in stage: verify esthetics, phonetics, and occlusion before processing; use wax try-in for complete dentures.

Post-insertion instructions: clean dentures daily, remove at night, and return for adjustment of sore spots.

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

Periodontal probing depth (PD) ≥4 mm with bleeding on probing suggests periodontitis; confirm with clinical attachment level (CAL).

Risk factors for periodontitis: smoking, diabetes, poor oral hygiene, genetic predisposition, and certain systemic conditions.

Scaling and root planing (SRP) is the initial therapy for periodontitis; re-evaluate after 4–6 weeks.

Aggressive periodontitis (now classified as periodontitis, grade C): rapid attachment loss, often in younger patients, familial aggregation.

Periodontal abscess: acute exacerbation of chronic periodontitis; treat with drainage, irrigation, and antibiotics if systemic involvement.

Gingival recession: apical migration of gingival margin; may be treated with connective tissue graft or coronally advanced flap.

Maintenance therapy: recall interval 3–6 months for periodontitis patients; monitor probing depths and bleeding.

Antibiotics in periodontics: adjunctive to SRP for aggressive or necrotizing periodontitis; avoid routine use for chronic periodontitis.

Angle's classification: Class I (normal molar relationship), Class II (mandible retruded), Class III (mandible protruded).

Cephalometric landmarks: Sella, Nasion, A-point, B-point; ANB angle indicates skeletal relationship (normal 2–4 degrees).

Growth modification: functional appliances (e.g., Twin Block) for Class II in growing patients; headgear to restrict maxillary growth.

Fixed appliances: brackets and archwires; use light continuous forces; avoid excessive force to prevent root resorption.

Retention: after active treatment, use retainers (fixed or removable) to prevent relapse; duration often indefinite.

Impacted canines: prevalence 1–2%; treat with surgical exposure and orthodontic traction if needed.

Cleft lip and palate: multidisciplinary care; presurgical orthopedics, lip repair at 3–6 months, palate repair at 9–12 months.

Extraction decisions: based on crowding, profile, and anchorage; premolar extractions common in severe crowding.

Clear aligners: effective for mild to moderate crowding; require patient compliance; not ideal for complex movements.

Primary dentition eruption: first tooth (mandibular central incisor) at 6–10 months; complete by 2.5–3 years.

Early childhood caries (ECC): caries in children under 6; associated with bottle feeding, frequent sugars, and poor oral hygiene.

Fluoride varnish: apply 5% NaF varnish every 3–6 months for caries prevention; safe for young children.

Pit and fissure sealants: apply to permanent molars soon after eruption; use resin-based sealant; ensure isolation.

Pulpotomy in primary molars: remove coronal pulp, place medicament (e.g., formocresol or MTA), and restore with stainless steel crown.

Space maintenance: after premature loss of primary molars, use band-and-loop or lingual arch to preserve space.

Behavior management: tell-show-do, positive reinforcement, and parental presence; avoid restraint unless necessary.

Teething: symptoms include drooling and irritability; treat with chilled teething ring; avoid lidocaine gels.

Preventive dentistry: diet counseling, oral hygiene instruction, and regular check-ups starting at first tooth eruption.

Diabetes mellitus: HbA1c >6.5% indicates diabetes; patients with poor control have increased risk of infection and delayed healing.

Hypertension: blood pressure >140/90 mmHg; avoid elective dental treatment if >180/110 mmHg; refer for medical management.

Antibiotic prophylaxis for infective endocarditis: indicated for high-risk cardiac conditions (e.g., prosthetic valve, previous endocarditis) before invasive dental procedures.

Asthma: avoid aspirin and NSAIDs in aspirin-sensitive patients; have bronchodilator available; avoid stress.

Warfarin: check INR; dental treatment safe if INR <3.5; avoid aspirin and NSAIDs; use local hemostatic measures.

Epilepsy: avoid triggers; have suction ready; do not place objects in mouth during seizure; use phenytoin caution for gingival hyperplasia.

Allergic reactions: anaphylaxis presents with urticaria, angioedema, bronchospasm; treat with intramuscular epinephrine (0.3–0.5 mg of 1:1000).

Hepatitis B: dental professionals should be vaccinated; post-exposure prophylaxis with immunoglobulin and vaccine if non-immune.

Surgical principles: aseptic technique, gentle tissue handling, hemostasis, and closure; monitor for infection.

Local anesthetics: lidocaine 2% with 1:100,000 epinephrine is standard; maximum dose 4.4 mg/kg (without epinephrine 7 mg/kg).

Epinephrine in local anesthetic: contraindicated in uncontrolled hyperthyroidism, pheochromocytoma, and severe cardiovascular disease.

Analgesics: ibuprofen 400–600 mg every 6–8 hours; acetaminophen 500–1000 mg every 6 hours; avoid aspirin in children (Reye's syndrome).

Antibiotics: amoxicillin 500 mg three times daily for odontogenic infections; penicillin allergy: clindamycin or azithromycin.

Antifungal: nystatin suspension or miconazole gel for oral candidiasis; fluconazole for resistant cases.

Sedation: benzodiazepines (e.g., midazolam) for anxiolysis; flumazenil is antagonist; monitor vital signs.

Drug interactions: NSAIDs reduce antihypertensive effect; erythromycin and azoles inhibit CYP3A4, increasing levels of some drugs.

Pregnancy: avoid tetracyclines and NSAIDs in third trimester; lidocaine is safe; use acetaminophen for pain.

Corticosteroids: short-term use for severe inflammation; taper if long-term; monitor blood glucose.

DMFT index: Decayed, Missing, Filled Teeth; measures caries experience in permanent dentition; dmft for primary teeth.

Community water fluoridation: optimal level 0.7–1.2 ppm depending on climate; reduces caries by 20–40%.

Epidemiology: prevalence is proportion of population with disease; incidence is new cases over time.

Screening: sensitivity is ability to correctly identify those with disease; specificity is ability to identify those without.

Oral health promotion: Ottawa Charter strategies include building healthy public policy, creating supportive environments, and strengthening community action.

Dental workforce planning: consider population-to-dentist ratio, geographic distribution, and access disparities.

Preventive programs: school-based sealant programs and fluoride mouthrinse are effective for high-risk groups.

Health education: use theory-based approaches (e.g., Health Belief Model) to change behavior.

Quality assurance: audit and peer review to improve care; use indicators like restoration longevity.

Informed consent: patient must be competent, receive adequate information (risks, benefits, alternatives), and consent voluntarily.

Confidentiality: protect patient information; disclose only with consent or legal requirement.

Autonomy: respect patient's right to make decisions; paternalism is ethically unacceptable.

Non-maleficence: do no harm; ensure competence and avoid unnecessary treatment.

Beneficence: act in patient's best interest; provide appropriate care.

Justice: fair distribution of resources and equal access to care.

Professional boundaries: avoid dual relationships; maintain appropriate doctor-patient relationship.

Mandatory reporting: report suspected child abuse or neglect; follow local laws.

Advertising: must be truthful and not misleading; avoid sensational claims.