Dental Morphological Trait
Definition
A discrete or quasi-continuous feature of tooth shape whose presence and expression grade are largely heritable. Examples include incisor shovelling, Carabelli trait, cusp 5 on the lower first molar, and the three-rooted lower first molar. Traits are scored on reference plaques, not by continuous measurement.
- Heritability
- Largely genetic in expression
- Examples
- Shovelling, Carabelli trait, cusp 5, 3-rooted molar
- Scoring method
- Reference plaques, graded expression
- Use
- Ancestry and population-affinity estimation
Common questions
Why are these traits scored on plaques rather than measured with calipers?+
Most of the traits are variations in the shape or presence of a feature rather than a continuous linear dimension, so a standardised set of reference images or casts (a plaque) lets different examiners assign a consistent grade to the same expression.
Can a single trait determine an individual's ancestry?+
No single trait is diagnostic; each trait only shifts a probability. Ancestry estimation combines the frequencies of several traits scored together, since any one trait appears across multiple population groups at differing rates.
Related terms
- ASUDAS
- Arizona State University Dental Anthropology System: a standardised plaque-based scoring system for 29 dental morphological traits developed by Christy Turner II and...
- Carabelli Trait
- An accessory cusp or groove on the mesiolingual surface of the maxillary first molar (and sometimes the second molar). It ranges from...
- Phenice-Style Dichotomy
- A simplification used in some research that collapses ASUDAS continuous scores into present/absent dichotomies for frequency comparison. Useful for older literature but...
- Population Affinity
- The preferred modern forensic-anthropological term for the relationship between an unidentified individual's skeletal morphology and a modern reference population. Replaces the older...
- Sinodont vs Sundadont
- Turner's two-pattern model of dental morphology variation in Asia and the Pacific. Sinodonts (northern Asian, East Asian, Indigenous American) have high frequencies...