Sex estimation accuracy through metric evaluation of dental root: a cone-beam computed tomography-based study

The degree of sexual dimorphism exhibited by teeth plays a crucial role in sex estimation, particularly as they are frequently found well-preserved. This study aimed to assess the presence of sexual dimorphism in the roots of upper lateral incisors, upper canines, and lower canines using cone-beam computed tomography (CBCT), and to develop and validate a formula for sex estimation. Linear measurements, surface area, and volumetric measurements were conducted on a total of 140 CBCT volumes (100 for evaluation and 40 for validation) from a Brazilian population, with an equal distribution of sexes, aged between 18 and 50. Statistical analysis involved the Kolmogorov-Smirnov test, unpaired t-test with Welch correction, Pearson's correlation test, logistic regression using the Backward Stepwise method, sieve test, Kappa test, intraclass correlation coefficient, and statistical power calculation (α=0.05). The three teeth showed sexual dimorphism, with measurements from males being statistically larger. Notably, only the formulas for the lower canine met the Mohan and Daubert admissibility criteria. The formula for assessing a sound root used included the mesiodistal diameter, axial cross-section volume, and two-thirds of the coronal cross-section volume. For evaluating reduced root length, the formula incorporated the mesiodistal diameter and axial cross-section volume. The accuracy of the lower canine formulas for sound and reduced root length were 89% and 87%, respectively. After validation, both formulas achieved an accuracy of 85%. In conclusion, the models combining measurements from the lower canine can be applied as a complementary method for sex estimation.