Morphometric Evaluation of Orbital Dimensions and Orbital Index in Adult Dry Human Skulls of Western India: A Descriptive Osteometric Study

Background: The orbit is a complex bony cavity essential for ocular function and protection. Variations in orbital dimensions across populations are influenced by genetic, ethnic, and regional factors. The orbital index (OI) serves as an anthropometric parameter to classify orbits and is valuable in forensic, anatomical, and surgical applications. Despite India's vast population diversity, limited region-specific morphometric data are available for the western Indian population.

Aim: To evaluate the orbital dimensions and orbital index in adult dry human skulls from Western India, and to classify orbital types based on the orbital index.

Materials and Methods: A descriptive osteometric study was conducted on 60 adult dry human skulls obtained from Anatomy departments of Medical colleges in Pune, Maharashtra. Orbital height, breadth, and perimeter were measured bilaterally using Vernier calipers and flexible thread. The orbital index was calculated as (orbital height/orbital breadth) × 100. Orbits were categorized into microseme (OI ≤ 83), mesoseme (OI 84–88.9), and megaseme (OI ≥ 89). Statistical analysis included descriptive statistics and paired t-tests.

Results: The mean orbital height was 31.37 ± 2.08 mm, and the mean orbital breadth was 38.79 ± 2.22 mm. The orbital index averaged 81.09 ± 6.81, with most orbits (63.33%) falling into the microseme category. The orbital breadth differed significantly between right and left orbits (p = 0.00), while height and perimeter showed no statistically significant side differences. The mean orbital perimeter was 128.04 ± 8.45 mm.

Conclusions: This study provides normative morphometric data for the Western Indian population, showing a predominance of microseme orbital type. The results underscore the need for region-specific orbital data for use in Anatomy, forensic identification, and clinical surgical planning