Home Dentistry Articles Striae of Retzius
Striae of Retzius
The striae of Retzius are incremental growth
lines seen in enamel and are results of enamel's development.
When viewed microscopically in cross-section, they appear as
concentric rings. In a longitudinal section, they appear as
a series of dark bands. The presence of the dark lines is similar
to the annual rings on a tree.
Darker lines in the striae of Retzius result
from systemic disturbances in the human body. For example, a
fever can cause some lines to appear darker than those surrounding
it. The neonatal line is the darkest band which represents the
enamel formed before and birth.
The formation of the striae of Retzius result
from a constriction of Tomes' processes in conjunction with
an increasing process of interrod enamel development.