Tooth transposition prevalence and type among sub-Saharan Africans

Area of Science:

• Dental Anthropology
• Human Genetics
• Paleodontology

Background:

• Tooth transposition, the positional exchange of two teeth, is a rare but studied dental anomaly.
• Previous research has primarily focused on prevalence and case studies, with limited geographic and temporal scope.
• Sub-Saharan Africa and premodern data remain underrepresented in dental transposition research.

Purpose of the Study:

• To investigate the prevalence, types, and associated abnormalities of tooth transposition in sub-Saharan Africa.
• To supplement existing dental anthropological and clinical research by including understudied regions and time periods.
• To explore potential genetic etiologies and diachronic changes in tooth transposition patterns.

Main Methods:

• Analysis of dental data from 51 sub-Saharan samples, encompassing over 2500 individuals from >10,000 BC to the 20th century.
• Inclusion of both modern (36 samples) and premodern (15 samples) age groups, with individuals aged 12 years and above.
• Tabulation of transposition presence, quadrant, and type, with statistical analysis using Poisson 95% confidence intervals for prevalence.

Main Results:

• A prevalence of 0.32% (6/1886) was found in modern individuals, with one premodern case identified.
• The primary observed transposition was the maxillary canine and first premolar (Mx.C.P1) exchange.
• Associated dental abnormalities included retained deciduous teeth, reduced permanent crowns, and agenesis.

Conclusions:

• This study enhances understanding of tooth transposition's geographic distribution, features, and historical depth in sub-Saharan Africa.
• Findings suggest a potential genetic basis for tooth transposition.
• Evidence indicates possible diachronic changes in transposition types, from Mx.C.P1 in premodern times to varied types more recently.