The 'peg-shaped' maxillary lateral incisor is the classic example of which phenomenon?

Correct answer: A. Localised microdontia

• A. CORRECT. The PEG LATERAL is the textbook example of LOCALISED (focal) MICRODONTIA — a single tooth that is genuinely smaller than normal, with a conical or tapered crown converging toward the incisal edge. It affects roughly 1-2% of the population, shows a strong hereditary component, is frequently BILATERAL, and is commonly seen with congenitally absent lateral incisors in the same family. The maxillary third molar is the other tooth most often affected.
• B. Concrescence is the union of two adjacent teeth by cementum, characteristically the maxillary second and third molars. It has nothing to do with tooth size.
• C. Dens evaginatus is an accessory cusp or tubercle projecting from the occlusal surface, most often on a mandibular premolar (Leong premolar) — an ADDITIONAL structure, the opposite of reduced size.
• D. Generalised true microdontia — all teeth genuinely small — is rare and is associated with pituitary dwarfism.

Note: RELATIVE (false) microdontia means teeth of NORMAL size that appear small because the JAWS are large — producing generalised spacing. TRUE microdontia means the teeth are genuinely small, either generalised (pituitary dwarfism) or localised (peg lateral, third molar). The peg lateral is TRUE localised microdontia.