Sexual Dimorphism in the Tooth-Crown Diameters

Mesiodistal and buccolingual crown dimensions of the right deciduous teeth of 133 white children were analyzed for information on sexual dimorphism and sex discrimination using discriminant analysis. Even though consistent differences were found for only 15 out of 20 paired measurements, five of them significant a t p = 0.05 or better, discriminant analysis showed the possibility of correctly sexing up to 75% of the juvenile sample, using a maximum of seven deciduous teeth. Discriminant functions have become a widely used method for the sexual diagnosis of human skeletal remains (Pons, '55; Thieme and Schull, '57; Giles, '64, '66, '70; Giles and Elliot, '63; Van Vark, '70; Ditch and Rose, '72; Van Gerven, '72; Garn et al., '77). Recently, several investigators have had success with discriminant functions based on the toothcrown diameters of the permanent teeth alone (Ditch and Rose, '72; Garn et al., '77). Although these investigators did not discuss the obvious implications of their results for the sexual diagnosis of the remains of children, i t is apparent that discriminant functions of the human dentition may provide reliable nonradiographic means for sexing immature skeletons. The sexual identification of immature remains has been an important problem in physical anthropology for many years. Various workers have attempted to use size dimorphism in the dentition as an aid to sexing the remains of children. Bailit and Hunt ('64) achieved 58% accuracy by comparing the developmental ages of the individual dentitions with published male and female standards of tooth formation from radiographs. These authors assigned to the individual the sex of the standard which caused the least variation among teeth. The discriminant functions employed by Ditch and Rose ('72) and Garn et al. ('77) improved the accuracy of sexing of older children to 85% or better. However, their disAM. J. PHYS. ANTHROP. (1978) 48: 77-82. criminant functions were based on the permanent teeth and would sex few children less than 12 years of age. If sexual dimorphism in tooth-crown size is as pronounced in the deciduous dentition as i t is in the permanent dentition, then i t may be possible to correctly assess the sex of children as young as two years. Percent sexual dimorphism between the male and female means for the dental measurements is presented together with tests for the significance of the differences of the means. Five sets of discriminant functions are calculated to determine the most reliable combination of measurements for sexing the deciduous dentition. One set of discriminant functions is based on the 20 dental measurements used in this paper, the other four sets of functions include only ten measurements each; these four sets are the maxillary teeth, the mandibular teeth, all mesiodistal measurements, and all buccolingual measurements. MATERIALS AND METHODS The mesiodistal and buccolingual diameters of the right deciduous teeth of 69 boys and 64 girls in the University School Growth Study of the University of Michigan were chosen for study. These individuals were selected from the sample of 204 white children used by Garn et al. ('77) because they had a complete set of measurements (10 mesiodistal, 10 buccolin-