Anatomical variation of infraorbital foramen position according to sex, side and cranium size

Abstract

Anaesthetic procedures focusing on the infraorbital nerve play an important role in dentist- ry and plastic surgery, as well as for treatment of pharmacologically resistant forms of trigemi- nal neuralgia; therefore, the anatomical localization of the infraorbital foramen (IOF) has been widely analysed by literature in relation with sex and side [1,2]. However, no study has so far considered the possible effect of general cranium size on the sexual dimorphism of measure- ments used for pinpointing the position of infraorbital foramen. This study aims at providing additional data concerning the position of infraorbital foramen assessing the possible influ- ence of cranium size on sexual dimorphism. Three measurements (distances from anterior nasal spine and inferior orbital rim, and angle at the intersection between the line from ante- rior nasal spine and the transversal plane parallel to the Frankfurt plane) were assessed on 100 skulls belonging to a contemporary skeletal collection with known sex and age (50 males and 50 females, mean age 68.4±19.1 years). Maximum cranial length, maximum cranial breadth, cra- nial heigth and bizygomatic breadth were measured as well, together with horizontal cephal- ic index and Giardina Y-index. Possible differences according to sex and side were assessed through two-way ANOVA test (p<0.05). Measurements showing statistically significant differ- ences according to sex were further assessed through one-way ANCOVA test including cranial measurements and indices as covariates (p<0.05). Statistically significant differences according to sex and side were found respectively for the distance from the anterior nasal spine and the angle at infraorbital foramen (p<0.05). One-way ANCOVA test verified that the sexual dimor- phism of the distance from the anterior nasal spine distance was independent from the all the assessed measurements and indices of cranium. The present study proved that sexually dimor- phic parameters useful for the localization of IOF do not depend upon the cranium size.