Dental Features of a Low-Caries Primitive Population

¹ Department of Dentistry, University of the Witwatersrand, Johannesburg, South Africa

A total of 458 Bushmen was examined clinically and plaster casts of the dentitions of 156 of them were studied. The Bushmen were studied in two groups: nomads and farm people.

Caries occurred in 9 per cent of Bushmen. The incidence was lowest in children, rose with age, and was highest in middle-aged people. It was more frequent in females and in farm Bushmen. The most caries-susceptible teeth were, in order, third maxillary, then first and third mandibular molars. Most cavities were interstitial, and occlusal cavities were generally found in third molars.

Most Bushmen had deep fissures and an intercusp angulation ranging from 90 to 115 degrees. They showed attrition at an early age and wear was severe in old age.

The caries-susceptible group had a higher incidence of four-cusped maxillary and five-cusped mandibular second and third molars, a higher incidence of the Y5 mandibular molar groove pattern, larger maxillary molars, a higher incidence of white flecking of enamel due to unknown causes, more attrition, and a higher periodontal disease index. Evolutionary simplification of molars appeared to be protective against dental caries.