lec.6 Enamel

All the E rods are deposited in daily appositional
rate or incremental form of 4micrometer such
increments are noticeable as a brownish bands
in ground section of E. in transverse ground
section these lines appear as concentric circles.
In longitudinal section they appear as dark lines
surround the crown they run obliquely. The
growth lines also appear in the surface of the E
as aridges (wave like grooves) as external
manifestation of stria of Retzius known as
perikymata.