Endoscopic resection of the pterygoid plates following incomplete transoral resection of an odontogenic myxoma

Odontogenic myxoma is a rare, benign, odontogenic tumour of mesenchymal origin with variable clinical behaviour and rates of recurrence. It has an incidence of about 0.07/million, and accounts for 0.5% – 20% of odontogenic tumours. 1,2–4 Maxillary and mandibular lesions occur in similar proportions. 5 Maxillary lesions are of particular concern because they are close to vital structures, are difficult to follow up, and access is difficult and transcutaneous procedures may be required. We describe the case of a 41-year-old man who presented to the Royal Melbourne Hospital with an incidentally-found cystic lesion that was associated with teeth 27 and 28. Biopsy examination showed that it was an odontogenic myxoma. Initial computed tomography (CT) showed a 10 × 10 × 20 mm, expansile lesion in the left posterior maxilla, with no perforation through the pterygoid plates. We attempted transoral resection twice with immediate reconstruction utilising buccal fat pad however the margins showed odontogenic myxoma within the bone at the posteriorsuperior aspect (Fig. 1). After discussion with the multidisciplinary tumour board, we decided to undertake an endoscopic resection of the residual pterygoid plates transnasally. The head and neck and neurosurgical units completed this as an alternative to a lateral “Obwegeser” approach. 6 Under a general anaesthetic, with the aid of Brainlab software (Brainlab AG, Munich, Germany), we used stereotactic instruments to do a left