Combination of teeth and Sternoclavicular Joint assessments for age estimation

Introduction: The combination of assessment of Dental Age (DA) and Sternoclavicular Joint (SCJ) has been advocated by the interdisciplinary Study Group on Forensic Age Diagnostics to improve the assessment of chronological age (CA). Studies have also shown that with aging, the dental pulp cavity gradually becomes smaller from continuous dentine deposition. The combination of root canal width measurements (RCW), ossification of the SCJ and DA estimation has not been explored. Objectives: to determine if pooling the results of DA, RCW and SCJ improves the accuracy and precision of CA estimation. Methods: Nineteen males and six females, (8 - 35 years) with both chest x-rays and DPT were identified. DA was calculated using the weighted average method. SCJ was assessed according to the five stages of Schmeling et al (2004) and mean ages of attainment per stage obtained. RCW was assessed grading the distal root canals of the permanent molars on the lower left side to obtain mean ages of attainment. The values of DA, SCJ and RCW were combined using weighted averages to give estimated age (EA), and agreement was measured using the Bland-Altman plot. Results: Only 8 subjects had developing teeth for which DA could be calculated. The Bland-Altman plot showed poor agreement between EA & CA (r = 0.60), and increasing scatter with increasing age. CA was compared to EA, DA and SCJ and RCW age. DA underestimated CA in 75% of the cases, SCJ in 36% and RCW in 80%. For the 8 subjects where DA could be calculated, EA was more closely related to DA than SCJ and RCW. SCJ was closer to CA than RCW for the other 16/25 subjects (64%), indicating that RCW was a poor predictor of CA. Conclusion: In a developing child, DA is a better predictor of CA than SCJ-RCW together.