ANATOMICAL VARIATIONS OF THE INFRAORBITAL NERVE ON COMPUTED TOMOGRAPHY
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Abstract
Objectives: To investigate the anatomical variations of the infraorbital nerve (ION) using computed tomography (CT) scans.
Materials and Methods: A cross-sectional descriptive study was conducted on 210 patients who underwent sinonasal CT scans at the University Medical Center Ho Chi Minh City from January 2025 to May 2025.
Results: The infraorbital nerves were classified according to the Ference classification system. The prevalence of ION type 1, type 2, and type 3 was 65.2%, 21.7%, and 13.1%, respectively. The angulation rate of the ION within the infraorbital canal was 64.8%, with statistically significant differences observed between types (p < 0.05). The mean angles between the anterior segment of the ION and the planes parallel to the hard palate and nasal septum were 58.9 ± 10.3° and 19.4 ± 7.5°, respectively. The mean distances from the infraorbital foramen (IOF) to the infraorbital rim (IOR) and the piriform aperture (PA) were 8.1 ± 1.8 mm and 12.5 ± 2.2 mm, respectively.
ION protrusion into the maxillary sinus was positively correlated with the IOF-IOR distance. The exit point of the nerve demonstrated a medial shift toward the lateral nasal wall. Haller cells were present in 28.8% of cases. Among these, the ION shared a wall with Haller cells in 28.9%, coursed within the maxillary sinus wall in 24.3%, and was associated with an accessory maxillary ostium in 15.0% of cases.
Conclusions: The morphology of the infraorbital nerve is highly diverse and correlates significantly with surrounding anatomical variations in the region.
Keywords
Infraorbital nerve (ION), infraorbital foramen (IOF), piriform aperture (PA), Haller cells, accessory maxillary ostium
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References
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