Mild dental fluorosis generally appears as barely visible opacities at the incisal or cuspal edges of teeth; it can also appear as white striations or lacy markings following the enamel perikymata
. (1,6) Severe dental fluorosis can have a heavily stained, pitted, friable enamel appearance.
This was achieved by creating standard perikymata profiles (SPPs), or standardized teeth, for each sex and species that allowed individual developmental sequences (IDSs) to be generated for each individual, tracking the position of each defect in the context of continuous perikymata (time).
pygmaeus acquiring defects faster; all other analyses including number of defects, number of perikymata between defects, and autocorrelation analysis revealed no differences between the two species.
from the Kayenta Formation (Early Jurassic: Pliensbachian) of Arizona (Sues 1985) in the presence of a distinct cingular cusp at the anterior (mesial) end of each row of cusps and pronounced perikymata
on the enamel.
Macroscopically, incremental pattern of enamel rods is exhibited on tooth surface as perikymata
, but microscopically, groups of enamel rods run in unique direction, which differ from adjacent group of enamel rods and results in forming different patterns of enamel rod endings on tooth surface.
Dental fluorosis is an hypomineralisation of the tooth hard tissues induced by an excessive intake of fluoride occurring during odontogenesis.4 Fluorosis is clinically manifested, depending on individual susceptibility, by opaque white spots, lines following the perikymata
direction, or wavy yellowish and brownish striations of the enamel.
In mild forms, it appears as chalky white lines on the enamel, which are usually symmetrical in contra-lateral teeth following the pathways of the perikymata
. In severe forms, the entire tooth surface is characterized by holes and yellow, brown or black spots.
The appearance of smooth, silky-glazed, sometimes dull enamel with the absence of perikymata
and intact enamel along the gingival margin are some typical signs of enamel erosion.
They estimated age at the time of death by counting a series of ridges on the surface of the enamel, called perikymata. Each layer of enamel framed by the ridges forms over an average of seven to eight days, according to Bromage and Dean.
Greater numbers of perikymata indicate faster, ape-like enamel growth; fewer numbers point to slower, human-like growth.
On the other hand, there are many omissions of terms, and the area of dental histology is a good example, where some frequently used terms have been omitted in the scientific literature and textbooks, such as the term perikymata
described that internal enamel exhibited atypical and more complex rod shapes and its surface presented the typical honeycomb pat- tern but no perikymata
,which, however, were ob- served on the outer surface of the tooth.61