primary dentition

The clinical image clearly depicts fusion between two deciduous maxillary incisors, evidenced by the visible groove running vertically along the crown, indicating the junction where two separate dental entities have united during development. This developmental dental anomaly occurs during the morphodifferentiation stage of tooth development when two normally separated tooth buds develop too close to each other, leading to contact and subsequent fusion of dental hard tissues.

This detailed chart compares five major dental notation systems across both deciduous (primary) and permanent dentitions, presenting a side-by-side visual reference of how each tooth is designated in different numbering conventions.