Morphometric Analysis of the Sphenoid Sinus in Sex Determination, Pneumatization Patterns, and Variant Neurovascular Relations among Nigerian Citizens in Port Harcourt

Abstract

Background: The sphenoid sinus, a highly variable and anatomically protected paranasal sinus, has important clinical and forensic applications due to its morphological variations and demonstrated sexual dimorphism, yet limited morphometric data exist for the Port Harcourt population. This study examined the morphometric characteristics of the sphenoid sinus amongst Nigerians living in Port Harcourt using computed tomography (CT) imaging, focusing on gender and age-related variations. A total of 200 retrospective CT scans of adults aged 18 - 70 years (100 males and 100 females) were reviewed. Participants were grouped into four age ranges: 18-25, 26-40, 41-55, and 56-70 years. Measurements of sinus height, width, depth, and volume were obtained using standard radiological software. Pneumatization patterns and neurovascular relations were also evaluated. Continuous variables that followed a normal distribution were expressed as mean ± standard deviation, while non-normally distributed data were summarized as median and interquartile range. Categorical variables were presented as frequencies and percentages. Independent t-tests were used to assess gender differences, one-way ANOVA to determine age-related variations, and chi-square tests for associations between categorical variables. Statistical significance was set at p < 0.05. The values of height, width, depth, and volume in males were 24.6 ± 3.8 mm, 23.9 ± 4.1 mm, 18.0 mm, and 10.2 ± 3.4 cm³, respectively, while in females, 22.1 ± 3.4 mm, 22.1 ± 3.7 mm, 16.0 mm, and 8.6 ± 2.1 cm³, respectively. These results showed that males exhibited significantly larger sphenoidal sinus dimensions and volumes compared to females. It also showed significant variations in sinus volume and depth across age groups, peaking in the 41-55 age group before slightly decreasing in the oldest group. The sellar pneumatization type was the most common (54%), followed by postsellar (22%), presellar (18%), and conchal (6%). Internal carotid artery protrusion was seen in 14% of subjects, while optic nerve protrusion occurred in 9%, and both protrusions were more common in males. These findings highlight that sphenoid sinus morphology varies significantly with gender and age among Nigerians. The study emphasizes the clinical importance of preoperative CT evaluation to prevent neurovascular injury and provides reference data valuable to radiologists, surgeons, and forensic anatomists.