Comparison of the Orbitozygomatic and Transmandibular Approaches to the Infratemporal Fossa.

Abstract

The infratemporal fossa (ITF) represents a complex anatomical region of critical relevance in skull base surgery, particularly due to its involvement in the extension of neoplastic lesions. Surgical access to this region remains technically demanding. The orbitozygomatic (OZ) and transmandibular (TM) approaches offer distinct anatomical perspectives and operative corridors. This study aimed to anatomically compare these two techniques to delineate their microsurgical fields, advantages, and limitations in accessing the ITF. A total of five silicone-injected, formalin-fixed cadaveric heads (10 sides) were dissected using surgical microscopes at magnifications ranging from ×6 to ×40. A standard OZ craniotomy was performed, followed by progressive drilling of the middle cranial fossa and resection of the greater sphenoid wing to expose the ITF. Subsequently, the TM approach was performed on the same cadavers to evaluate its added exposure. Anatomical landmarks, neurovascular structures, and spatial relationships were meticulously documented and compared across approaches. The OZ approach enabled wide exposure of the anterior and middle ITF, particularly through the anterolateral triangle and foramina of the middle fossa with minimal brain retraction. However, access to the posterior ITF, maxillary artery, and lower cranial nerves was limited. The TM approach, conversely, provided extended visualization of the middle and posterior ITF, superior control of the maxillary artery, and exposure of deep neurovascular structures, including the internal carotid artery and cranial nerves IX-XII. Integration of both approaches offered a complementary panoramic view of the ITF. The OZ approach is optimal for anterior and middle ITF lesions with orbital or cavernous sinus extension, while the TM approach is more effective for posterior ITF pathologies requiring wider vascular and neural access. Combining both strategies may offer a tailored approach for complex skull base surgeries involving the ITF.