Transpterygoid Approach to Mandiblar Nerve

Background: One of the most important landmarks for the endonasal endoscopic location of the poststyloid parapharyngeal space, hence the internal carotid artery (ICA),are the third division of the trigeminal nerve at the level of foramen ovale and the medial pterygoid plate.

Objective: To study the anatomical relations of the mandibular nerve through the endoscopic endonasal transpterygoid approach.

Methods: A cadaveric study was performed on five adult specimens.Endoscopic medial maxillectomy and the complete resection of the posterior wall of the maxillary antrum was performed. To dissect the most lateral aspect of the infratemporal fossa, extension of the medial maxillectomy anteriorly was done. Endoscopic Denker's or Strurman-Canfield approach was done. Dissection of the pterygopalatine fossa was done with identification of maxillary artery branches, V2 (maxillary nerve) and mastication muscles. Resection of the lateral pterygoid muscle and drilling the lateral pterygoid plate improve exposure of the infratemporal fossa, including V3 (mandibular nerve), which lies posterior to the lateral pterygoid plate.

Results: A total of ten infratemporal and pterygopalatine fossae (five cadaveric specimens) were dissected endoscopically using a transpterygoid approach. Dissection of V3 and other contents of infratemporal fossa was done.

Conclusions: Endoscopic transpterygoid approach becomes the standard surgical solution for most of benign and some malignant tumors that involve the infratemporal fossa and middle cranial fossa. Good understanding of the V3 anatomy allows safe resection of tumors extending to the infratemporal fossa and poststyloid parapharyngeal space.

• LPM (lateral pterygoid muscle)

• ICA (internal carotid artery)

• IMA (internal maxillary artery)

• TMJ (tempromandibular joint)

• ITF (infratemporal fossa).

Keywords

Transpterygoid approach - V2 - V3 - internal carotid artery (ICA) - infratemporal fossa (ITF).