INBDE Practice Exam 2026 – Complete Study Guide

Perikymata refers to the horizontal ridges or grooves on the surface of the tooth enamel. These ridges are an external manifestation of the incremental growth lines known as the Striae of Retzius. The Striae of Retzius are incremental lines in the enamel that result from the deposition of enamel during tooth development. These lines appear as a result of periodic interruptions in enamel formation. In this context, the external manifestations of the Striae of Retzius are represented by the perikymata on the tooth's surface.

The other options are not correct in this context:

A. Cementum is a mineralized tissue covering the roots of teeth, not related to the Striae of Retzius.

C. Enamel Rods are structural units of enamel, but they are not considered external manifestations of the Striae of Retzius.

D. Dentin is a mineralized tissue underlying the enamel, and it is not associated with the external manifestations of the Striae of Retzius.