Validity of Maxillary Intra-incisor–Canine Width as a Novel Indicator for Sex Determination

Biological sex determination is challenging in forensic sciences, especially if the traditional dental measures are not present due to loss of teeth or damage. Intercanine and intermolar measurements have been widely used, but are limited in such a context. This cross-sectional study was aimed at evaluating the validity of intra-incisor-canine width as a sex identifying instrument, as well as to test its reliability in association with intercanine and intermolar width. Sixty adults (30 men, 30 women; mean age 21.5 ± 2.1 years) with Angle Class I occlusion were included in the sample. Maxillary dental impressions and bite marks were obtained. Traditional intercanine and intermolar widths, along with those of the new bilateral incisor-to-canine distances, were measured using standard odontometric measures. Statistical tests involving Student’s t -tests, Pearson correlations, and logistic regression were used. There was significant sexual dimorphism in intermolar width, both in dental casts ( p = .009). Maxillary incisors to canines showed a significant difference between sexes bilaterally in dental casts and in bite marks ( p < .001). Binary logistic regression analysis showed that the odds of being male increased by 2.67 times (95% CI: 1.41–5.05) for every 1 mm increase in incisor-to-canine width, with a classification accuracy of 91.7% for sex determination. The incisor-to-canine width of the maxillary arch can be an adjunctive method to sex identification in forensic dentistry when the traditional dental parametric measurements are not available.