A comprehensive morphometric analysis of the anterior nasal spine: insights from cone beam computed tomography

The anterior nasal spine (ANS) is a critical anatomical landmark with surgical, orthodontic, and forensic significance. This study aimed to evaluate the morphometric and morphological features of the ANS using cone beam computed tomography (CBCT) and to analyze their relationship with age and gender.

A total of 979 CBCT scans (561 females, 418 males; age range 18-80 years) were retrospectively examined. Linear (length, width) and angular measurements of the ANS were performed in axial and sagittal sections. Morphological assessment was conducted based on four predefined shape categories: triangular, irregular, single rod, and double rod. Statistical analyses included nonparametric tests, correlation analysis, and reliability assessment with intraclass correlation coefficients (ICC) and Weighted Kappa.

Mean ANS dimensions were 9.19 ± 2.06 mm (axial length), 5.56 ± 1.86 mm (sagittal length), 108.94° ± 12.51 (axial angle), 70.14° ± 16.26 (sagittal angle), and 5.72 ± 1.92 mm (width). Significant gender differences were observed in all parameters except width (p > 0.05). A weak positive correlation was found between width and age (p = 0.047). The triangular shape was the most prevalent (54.5%), followed by double rod (23.1%), single rod (13.4%), and irregular (9%). Shape distribution also showed significant gender variation. Reliability analysis indicated excellent agreement (ICC: 0.932-0.998).

CBCT-based morphometric analysis revealed gender-specific differences in ANS dimensions and morphology. These findings emphasize the clinical importance of the ANS in surgical planning and orthodontics, as well as its potential value in forensic and anthropological identification.