Foramen Rotundum Dimensions and Landmarks in Indian Adults: Anatomical Insight for Skull Base Surgery

The foramen rotundum (FR) is a critical skull base aperture transmitting the maxillary division of the trigeminal nerve. Its anatomical variations have significant implications for diagnosis and surgical approaches to skull base lesions. However, population-specific morphometric data for the Indian population remain limited.

This study aims to evaluate the morphometric characteristics and anatomical features of the FR in Indian adults using both dry skulls and computed tomography (CT) scans, with emphasis on establishing surgical landmarks for safe skull base surgery.

Thirty dry adult human skulls and thirty high-resolution CT scans of adult patients (≥18 years) without skull pathology were examined. Morphometric measurements of the FR, including breadth, height and distance from the anterior clinoid process, were recorded using digital Vernier calipers (dry skulls) and specialized CT analysis software. Statistical comparison between left and right sides was performed using paired t-tests (p≤0.05).

The FR was bilaterally present in all specimens with predominantly round shape and regular margins. No accessory foramina, septations, or confluence were observed. In dry skulls, mean breadth and height measured 3.82±0.99 mm and 3.59±0.65 mm (left) and 3.82±0.91 mm and 3.54±0.77 mm (right), respectively. Corresponding CT scan measurements were 2.94±0.53 mm and 2.54±0.44 mm (left) and 2.85±0.45 mm and 2.40±0.44 mm (right). No statistically significant asymmetry was observed between sides. The mean distance from the anterior clinoid process to FR was 10.50±1.19 mm (dry skulls) and 14.06±1.86 mm (CT scans), with no significant lateralization.

The present study establishes population-specific morphometric data for FR in Indian adults and validates the anterior clinoid process as a reliable surgical landmark. These findings provide essential reference points for endoscopic and lateral skull base approaches, enhancing diagnostic accuracy and surgical safety while highlighting the need for population-tailored anatomical references in clinical practice.