Tooth loss and retention: analysis on 500 maxillae of a multitribal group of Bantu-speaking South African blacks.

This study analyzes tooth loss and retention in 500 dry maxillae of adult South African Bantu-speaking blacks. The tribe, sex, and stated age at death were available. Specimens were equally distributed over the third to the seventh decades of life. The presence of dental units was recorded and analyzed between and within age groups. A total of 5063 dental units was recorded. Reduction of the frequency of dental units was mild and not significant between the third and fourth decades of life and between the sixth and seventh. Severe and significant tooth loss was recorded between the fourth and the fifth, and between the fifth and the sixth decades of life. Specimens from younger individuals (from 21 to 30 years of age) retained more teeth in the anterior region; after the third decade of life, there was a clear and significant persistence of canines with tendency toward loss of teeth anterior and posterior to them. Based upon the present observations and previous studies in this population, it is suggested that: (a) in most teeth, tooth retention pattern is indirectly related to periodontal bone loss (In the canines, however, the long roots rather than "resistance" to periodontitis may be the cause for the relatively high longevity rate); and (b) caries may have been the main cause for tooth loss until the fourth decade of life--later, periodontal disease may have become the predominant reason.