Agenesis of the permanent teeth in sub-Saharan Africans: Prevalence, patterns, interpretations

Objective: Dental agenesis data in modern and premodern sub-Saharan Africans are presented by region, West, Central, East, and South, and by sex. Beyond characterizing the anomaly, comparisons are made with other populations and future work is encouraged. The findings should be of use to dental clinicians and anthropologists. Methods: Agenesis of the UI2, LI1, UP2, LP2, UM3, and LM3 was recorded in 52 discrete samples of mainly skeletal dentitions (n=2162) from across the subcontinent. After dividing into temporal categories, regional pooling was effected for adequate sample sizes across the vast geographic area. Only adults were included to record M3 status. Analyses included 95% confidence intervals and chi-square comparisons by region and sex. Results: Of 1668 modern individuals 2.3% have UI2-LP2 agenesis (CI 1.6-3.1%). Regional and sex differences are non-significant, though females are most affected. For M3s it is 7.0% (5.7-8.4%), with the Central region sample differing significantly from the East and South. Females again have greater prevalence, with the difference in the West significant. UI2-LP2 agenesis affects 0.6% of 494 premodern individuals (0.1-1.8%), while M3 agenesis is 8.5% (6.1-11.5%). None of these differences are significant. Conclusions: Rates are toward the low end of global ranges, including 0.0-12.6% for UI2-LP2 from case reports, and 5.3-56.0% for M3 agenesis. With exceptions, generally insignificant inter-region differences imply that rates reasonably represent sub-Saharan peoples overall. Results will be of interest to anthropologists, but those related to risk factors, patterning, and prevalence may assist clinicians in tailoring treatment, while informing patients how this anomaly differs by population ancestry.