To describe a novel transvestibular endoscopic approach for the exposure, exploration, and resection of lesions in the infratemporal fossa （ITF） and parapharyngeal space （PPS）.

Surgical technique and clinical feasibilty of a novel approach to the middle cranial base.

The transvestibular endoscopic approach was applied to four patients with lesions involving the ITF and PPS. Through a vertical oral mucosal incision along the ascending ramus of the mandible, an optical corridor to the ITF and PPS was created and maintained with the aid of a Hardy speculum. The contents of the ITF and PPS were explored with the aid of a 0-degree 4-mm rigid endoscope.

Four patients underwent exploration of their right-sided ITF and PPS. The approach provided exposure and access from the middle cranial base at the level of the foramen ovale to the mid-PPS. Branches of the trigeminal nerve in the ITF were safely explored and preserved. Exposure and visualization of the internal maxillary artery and branches were achieved. Of the four patients, two underwent resection of a primary and a recurrent pleomorphic adenoma, one had chronic pain relief from a large synovial chondromatosis, and one had debulking of a recurrent mucoepidermoid carcinoma. The only complications were self-limiting hypoesthesia of the lip in one patient and transient dysphagia in another patient.

The transvestibular endoscopic approach to the ITF and PPS offers direct and minimally invasive access to select lesions within this region. Further use of this approach will allow us to determine its potential and limitations.