Abstract
In the present study, sexual differences in deciduous tooth crown diameters were investigated in Japanese children. Plaster casts of the deciduous dentitions obtained from 50 boys and 50 girls were examined. Mesiodistal and buccolingual crown diameters were measured using a digital caliper (0.01mm) according to the method of Sugiyama & Kurosu (1964). These measurements were performed three times by one of the present authors, and intra-observer measurement errors were calculated by the single determination method. The crown index [(buccolingual crown diameter/mesiodistal crown diameter)×100] was calculated in order to provide a comparison of crown proportions. Percentage sexual differences were calculated for each measurement and index.
Intra-observer measurement errors were very small (<0.1 mm) and are unlikely to have influenced the statistical analysis. The mean values for all of the crown diameters examined were larger in boys than in girls, and percentage sexual differences ranged from approximately 1 to 3%. In the maxillary deciduous teeth, the buccolingual crown diameters had larger percentage sexual differences than did the mesiodistal crown diameters. In contrast, in the mandibular deciduous teeth, the mesiodistal crown diameters had larger percentage sexual differences than the buccolingual crown diameters. Buccolingual crown diameters varied more than the mesiodistal crown diameters. Crown indices showed less sexual differences, with the exception of the mandibular deciduous canine.
