Enamel multidien biological timing and body size variability among individuals of Chinese Han and Tibetan origins.

Aims: To measure the number of days of enamel formation between periodic striae of Retzius growth lines, the Retzius periodicity (RP), and to compare this multi-day, or multidien rhythm, to body height and weight among people from Beijing, China and Lhasa, Tibet/China.

Subjects And Methods: Subjects requiring dental extractions from clinics in Beijing, China ( = 338) and Lhasa, Tibet/China ( = 227) provided a tooth and body size information. Multiple observers examined histological sections of the teeth and recorded RP.