Effectiveness of combining third molar maturity index and palatal median suture maturity for age assessment in Yunnan adolescents.

Accurately determining whether an individual has reached the legal age of adulthood (e.g., 18 years old) is crucial in judicial practice. With increasing global migration flows, developing reliable biological age assessment methods has become a significant challenge in forensic anthropology. This study aims to explore the value of combined third molar maturity and palatal midline maturity in assessing adulthood among Han adolescents in Yunnan Province through cone-beam computed tomography (CBCT), This study included dental CBCT images from 300 individuals aged 16 to 21 years, comprising 140 males and 160 females. The Demirjian developmental stage of the left mandibular third molar and the Angelieri maturity stage of the midpalatal suture were assessed and subjected to statistical analysis. Both the multiple linear regression model and Fisher’s discriminant function demonstrated statistical significance (P < 0.01). Both the Demirjian stage of the third molar and the palatal midline maturation stage showed significant positive correlations with chronological age (P < 0.01). The combined model constructed using multiple linear regression exhibited a higher coefficient of determination and lower prediction error compared to single-indicator models. The discriminant function designed for the 18-year-old threshold demonstrated good discriminatory efficacy. A multimodal age estimation model based on the combined development of third molars and palatal midline maturation enhances the accuracy of age estimation for Han adolescents in Yunnan Province, and can be used as a region-specific reference for forensic age assessment of this target population.