Figure 4.

Relationship among the Tomes’ process, the pits, and rod/interrod development in prismatic enamel. (A) Pits of Tomes’ processes remain after removal of ameloblasts from secretory enamel and have a keyhole-like morphology that renders lateral movement of ameloblasts impossible (blocked arrows) (with permission from Boyde 1967). (B) Pits in secretory enamel from developing molar of a 5-d-old rodent show rectangular morphology, which allows for sliding movement of ameloblasts as indicated by arrows. (C) Classic schematic of the microstructure of human enamel composed of keyhole-like enamel rods (modified with permission from Meckel et al. 1965).