The incidence of asymmetrical left/right skeletal and dental development in an Australian population and the effect of this on forensic age estimations

The prevalence of developmental asymmetry between left and right sides of the body in the third molar tooth and medial clavicular epiphysis is examined in a contemporary Australian population (92% Caucasian). The contention that differences between left and right side developmental timing is statistically insignificant, and can therefore be ignored in forensic age estimation procedures, is questioned. It was found that of a population sample of 604 individuals, 177 displayed asymmetrical timing in development between antimeres of the third molar, the medial clavicle or both. There was no correlation found between the third molar tooth and medial clavicular epiphysis in terms of left/right synchronicity. For those individuals differing in development by two or more developmental stages in either age marker or one stage in both age markers, the effect upon the accuracy of forensic age estimations can be significant. Differences in age estimates for each side were as much as 3.1 years. Age estimations based on one side only may not provide the best estimate for an individual, and more accurate results can be achieved if both sides are taken into consideration. A protocol for dealing with asymmetrical development is discussed with reference to the multifactorial age estimation method proposed by the same authors in previous research.