Association of antegonial notch size with craniofacial morphology and masticatory muscle dimensions

The antegonial notch (AGN) is a structure that has been variably described across studies, with diverse findings regarding its role and association with craniofacial morphology, which is attributed to differing methodologies and the lack of control for sex and size. This study aimed to elucidate the variability of the AGN and examine its association with facial types, skeletal and muscular parameters. This study was carried out using the CT scans of 311 individuals aged 18-95 years. Facial type, skeletal and muscular measurements were recorded. Mann-Whitney and Kruskal-Wallis tests were conducted to examine AGN area differences between the sexes and facial types. Spearman correlation was used to explore the relationships between AGN and the skeletal and muscular parameters. AGN was found to be sex dependent: it was absent in 22.7% of males and 35.1% of females; its size was larger in males than in females (55 mm² vs. 31 mm²) (p < 0.001). The AGN area did not vary between the facial types (p > 0.073). Its size showed weak correlations with skeletal parameters and no associations with masticatory muscles (p > 0.375). Our findings indicate that the AGN is more prevalent and pronounced in males, and that there was no evidence of a functional relationship.