Quantitative genetic analyses of postcanine morphological crown variation.

Area of Science:

• Anthropology
• Genetics
• Dentistry

Background:

• Tooth crown morphology offers insights into human evolution and population genetics.
• Understanding the genetic basis of dental traits is crucial for anthropological studies.
• Previous research has explored heritability of dental traits, but postcanine teeth require further investigation.

Purpose of the Study:

• To estimate narrow-sense heritability and bivariate genetic correlation for 14 tooth crown morphological variants.
• To inform data collection and analytical practices in dental biodistance research.
• To provide insights into the developmental integration of molar crowns.

Main Methods:

• Utilized dental casts from the Menegaz-Bock collection (African American individuals).
• Applied the Arizona State University Dental Anthropology System for trait scoring.
• Generated heritability and genetic correlation estimates using SOLAR software, accounting for covariates like age and sex.

Main Results:

• Heritability estimates were mostly nonsignificant for postcanine teeth, but significant estimates were moderate to high.
• Directional asymmetry in environmental variance was observed between left and right sides.
• Genetic correlations were moderate among same-tooth and adjacent-tooth traits but low for different traits on the same tooth.

Conclusions:

• Significant heritabilities for postcanine traits were higher than for anterior teeth.
• Genetic correlations were generally unremarkable, potentially due to statistical power limitations.
• Findings question the pooling of sexes and sides in dental biodistance analyses, suggesting potential biases.