Morphometric Evaluation of Frontal and Maxillary Sinuses and Bizygomatic Distance of Igbos In South-East and Ogonis in South-South Nigeria Using Computerized Tomography Scan

Background: Radiological identification is important in clinical, surgical and forensic medicine particularly in the absence of comparative deoxyribonucleic Acid (DNA) samples and fingerprints. Aim is to establish the morphometry of frontal sinus (FS), maxillary sinus (MS) and bizygomatic distance (BZD) and their relationship with age and gender in Igbos and Ogonis of Nigeria using computed tomography (CT).

Methods: Head CT scans of 625 subjects (477 Igbos and 148 Ogonis) between 18 and 85 years, showing normal FS, MS and BZD, were measured using DICOM viewer software. The Igbos and Ogonis were 247 males and 230 females; 84 males and 64 females respectively. The height, width and depth of the sinuses, intermaxillary sinus distances (IMD) and BZD were measured in centimeters (cm). The data were analyzed using SPSS version 20 and difference between groups was obtained using one way ANOVA. P-value less than 0.05 was considered as statistically significant.

Results: Mean values for the right and left MS volume for the Igbos are 13.79 ±10.91 and 13.81±11.03 and for the Ogonis 20.84±5.83 and 20.19±5.59 cm respectively. All FS dimensions are higher in the Igbos (P<0.001) except right FS depth. Mean IMD are 3.64±0.50 and 3.39±0.45 cm in the Igbos and Ogonis respectively (P<0.001). Ogonis have higher BZD (P>0.05). In both groups, males had larger values in both FS depth, MS dimensions and BZD (P<0.001). Age correlated positively with left FS height and IMD. Prevalence of unilateral FS aplasia was 3.35% on the right and 1.47% on the left among the Igbos while the Ogonis have 2.03% on the right and 2.70% on the left. Bilateral FS aplasia was 2.94% among the Igbos but not observed among the Ogonis.

Conclusion: Normative values is established. Ethnic differences exists with Igbos significantly having higher values of FS and IMD while in the Ogonis, the MS dimensions are higher. These findings would act as a guide for facial reconstructive surgeries, forensic experts and classification of fossil remains in anthropology.