Oral and dental anatomy, histology, physiology and embryology
What this domain tests
This domain covers tooth and periodontal anatomy, histology, physiology and embryology, and the language used to describe teeth accurately.
Core rules
- FDI notation uses two digits: quadrant 1-4 and tooth 1-8. Tooth 36 is the permanent mandibular left first molar.
- Enamel is highly mineralised and cannot regenerate; dentine is tubular and vital; cementum covers the root; the pulp contains nerves and vessels.
- The periodontium comprises gingiva, periodontal ligament, cementum and alveolar bone.
- Primary dentition has 20 teeth; permanent dentition has 32, including third molars.
- Embryology: neural crest cells form dental mesenchyme; dental lamina gives rise to the bud, cap and bell stages; Hertwig's epithelial root sheath shapes the root.
- Saliva buffers acids and supports remineralisation; reduced flow raises caries and erosion risk.
Worked example
A chart entry says 36 mesial pocket. Using FDI, 3 = mandibular left, 6 = first molar. The mesial surface faces the midline, so the instrument approach differs from the distal. Confirm the tooth by counting and by morphology: mandibular first molars usually have two roots.
Traps
Mixing FDI and Universal numbers; calling a primary molar by a permanent number; saying enamel remineralises like dentine; forgetting that cementum is part of the periodontium.