A COMPARISON OF RADIOGRAPHIC AND ANATOMICAL EVIDENCE OF TOOTH DEVELOPMENT IN INFANT APES

This study assesses dental development in a sample of 8 known-age infa nt orangutans and chimpanzees in order to examine discrepancies betwee n radiographic analyses of tooth development and the actual developing teeth. All crania were radiographed and any developing teeth then ext racted for comparison. The height of deciduous teeth was measured both on the radiographs and on the extracted teeth to assess the accuracy of radiographic tooth measurements. A comparison between the radiograp hic and actual measurements of the deciduous teeth reveals substantial discrepancies. For permanent teeth, the degree of radiographic undere stimation of tooth development was found to vary depending on the toot h being studied, its stage of development (early stages are particular ly problematic) and the radiographic techniques used. Examination of t he dissected teeth also revealed earlier times of onset of calcificati on for I-2(2) C-1(1) P-3-4(3-4) and M(2) than reported in previous stu dies. For the canine and M(2)(2), upper and lower homologues appear to begin development at different times, but there is no apparent differ ence in onset times between other upper and lower homologues.