Objectives Dental morphology plays a key role in reconstructing population history and evolutionary relationships at global, regional, and intracemetery scales. At the inter‐individual level, it is assumed that close biological kin exhibit greater phenotypic similarity than non‐relatives. Heritability estimates provide one measure of phenotypic resemblance but are not easily incorporated into analyses of archaeological samples. In this study we evaluate the assumption that relatives are more similar phenotypically than non‐relatives. We compare results for permanent dental morphology to those obtained using deciduous dental morphology in a matched dataset (Paul & Stojanowski, ). Materials and Methods Permanent trait expression was scored from dental casts representing 69 sibling pairs, curated as part of the longitudinal Burlington Growth Study. Simulating a biodistance approach, 22 morphological traits of permanent tooth crowns were used to generate 69 inter‐relative and 2,076 non‐relative Euclidean distances. Following distance ordination, family‐specific dispersion values were calculated from multidimensional scaling coordinates. Output was compared to that of a previous study that focused on deciduous crown variation in the same set of individuals (Paul & Stojanowski, ). Mantel tests were used to evaluate the correlation of a proxy genetic distance matrix to both the permanent and deciduous dental distance matrices. Results On average, inter‐relative distances generated from morphological traits of permanent tooth crowns were smaller than expected by chance based on resampling (p < 0.001). While family‐specific dispersion varied greatly for both permanent and deciduous datasets, over 75% of the families exhibited greater dispersion with permanent traits. This suggests that morphological traits of the permanent dentition provide a less faithful reflection of biological relatedness than morphological traits of the deciduous dentition. Mantel tests indicate that both the deciduous and permanent distance matrices are significantly correlated with a matrix of genetic relatedness coefficients; however, the magnitude of the correlations was low. Discussion Overall, morphological traits of permanent tooth crowns perform moderately well in distinguishing relatives from non‐relatives, but deciduous crown variations may provide a more direct reflection of the underlying genetic structure of intra‐site or intra‐cemetery samples. These findings have implications for bioarchaeological research and biodistance practices. In particular, morphological traits of the deciduous dentition should be incorporated into standard data collection protocols because of their stronger signal of relatedness.