Introduction: Surgical approach to the infratemporal fossa is challenging due to its location; it is located beneath the middle cranial fossa and surrounded by the maxilla, mandible, and eloquent anatomical structures such as nasopharynx and carotid artery. Most cadaveric and clinical studies published so far have focused on the anatomical overview of the surgical approach to the infratemporal fossa, which can be difficult to understand for the skull base surgery trainees. This study aims to provide an educational guide for learning the anatomy of the infratemporal fossa especially for the trainees.
Methods: Two formalin-perfused adult cadaveric heads, whose arteries and veins were injected with red and blue colored silicone were dissected under an operating microscope. Bone dissection was done using a high-speed drill. For anatomically-oriented dissection, one specimen was dissected from below and towards the skull base to demonstrate the three-dimensional anatomical relationships of the infratemporal fossa. In addition, the postauricular transtemporal approach, which is one of the extensive surgical approach to the infratemporal fossa, was performed following the standard steps of the surgical procedures.
Results: The neural, muscular, and arterial relationships of the infratemporal fossa were demonstrated by performing stepwise cadaveric dissection from below and towards the skull base and the operative, postauricular transtemporal approach. The key steps described included skin flap elevation, fronto-temporal and suboccipital craniotomy, middle cranial fossa drilling, mandibulotomy, mastoidectomy, and high cervical dissection.
Conclusion: Surgical approach to the infratemporal fossa is complex and technically challenging. Anatomically-oriented and operative-style dissections are essential for trainees to understand the three-dimensional anatomy of the infratemporal fossa. This study will serve as a guide for skull base surgery trainees to improve the understanding of the surgical anatomy of the infratemporal fossa.
Figure 1. Anatomically oriented dissection of the infratemporal fossa (A-H)
Figure 6. Postauricular transtemporal approach (Middle fossa dissection) (A-N)
