Sex differences in permanent mandibular tooth development in Macaca nemestrina

Sex differences in dental maturation prior to and during adolescence in 40 unrelated Macaca nemestrina were investigated. The data consisted of mixed longitudinal cephalometric films taken at regular intervals during this period. The mandibular premolars and molars presented the following sequence of initial calcification: M₁ P₃ (M₂ P₄) M₃. In all stages of development, females tended to mature earlier than males, although only 10 of the 22 stages studied were significantly different. Of these, M₃ crown completion, M₁ cleft formation, and M₃ apical closure were the most reliable for discriminating between sexes. The rate of formation of all teeth, with the exception of M₃, was faster in the females than the males, and in both sexes the teeth completed their formation during adolescence. It was suggested that these sex differences in dental maturation may be associated with differences in the timing of hormone secretion, i.e., menarche.