The morphometric and cephalometric study of anterior cranial landmarks for surgery

The aim of this work was to determine reliable bony landmarks for the anterior skull base and to standardize some specific dimensions among the frontal sinus and neighboring structures for safe anterior cranial surgery.

The study consisted of a topographical anatomic examination and cephalometric analysis of the skull. Thirty adult skulls (60 sides) were studied regarding the localization and dimensions of the supraorbital foramen (SOF), frontal sinus (FS), frontozygomatic fissure, infraorbital foramen, anterior nasal spine, and nasion. Differences between the measurement of skulls and cephalograms were analyzed by Student's t test. The Pearson correlation test was used for statistical analysis of the cephalogram.

Examination of the 60 sides of the bony heads revealed that the shape of the SOF was a foramen in 25 sides (41%), a notch in 29 sides (49%), and a groove in 6 sides (10%). A total of 20 (33%) SOFs were inside the FS and the mean distance was 6.3+1.34 mm from the lateral border of the sinus, 27 (45%) of SOFs were outside of the FS and the mean distance was 8.8+2.01 mm, and 13 (22%) of SOFs were at the border of the FS. According to our measurements the medial border of the craniotomy should be placed approximately 43 mm lateral to the nasion to avoid entering into the frontal sinus.

To plan and to decide the convenient and safe anterior midline skull base approach and to avoid postoperative complications, bony landmarks and anatomic measurements around the SOF and FS will be helpful for the surgeon to constitute a simplification of topographic anatomy.