Endoscopic Endonasal Approach to the Medial Aspect of the Temporomandibular Joint Region

BACKGROUND: The temporomandibular joint (TMJ) region is the most superolateral aspect of exposure via an endonasal corridor, while studies regarding the endonasal approach to this specific region are lacking. This study aimed to provide a detailed step-by-step surgical technique to reveal the medial aspect of the TMJ region on cadaveric dissection, and to retrospectively review endonasal removal of tumors in this specific region. METHODS: Cadaveric dissection was performed on 4 specimens to illustrate the surgical technique of endonasal access to the medial aspect of the TMJ region. Radiological measurement of distances from anterior nasal spine (D1), lateral pterygoid plate (D2), and foramen ovale (D3) to medial TMJ of bilateral sides on 100 continuous CT scans was performed. Five patients harbored tumors at the medial aspect of the TMJ region who underwent endonasal tumor removal were included in the study. The feasibility, perioperative morbidities, and clinical outcomes were assessed. RESULTS: The contents at the medial aspect of TMJ region could be adequately exposed via an endonasal corridor on all 8 cadaveric sides. The average distances of D1, D2, and D3 were 88.20 ± 8.2 mm, 22.80 ± 3.4 mm, and 19.93 ± 1.73 mm, respectively. The pathologies were osteoblastoma (n = 2) and chemotherapeutic malignancies (one with osteosarcoma and two with rhabdomyosarcoma). Gross total resection was achieved in all five patients. A comprehensive treatment strategy was performed for 3 patients with malignancies. Postoperative trismus was encountered, while it gradually improved with minimal impact on quality of life. With an average follow up of 24.4 ± 9.84 months, no recurrence was detected. CONCLUSION: It is feasible to perform an endonasal approach to the medial aspect of the TMJ region. For select tumors, an endonasal approach can serve as a viable option for tumor removal with few complications in experienced hands.