A 12-year-old woman reported having suffered a left facial abscess of dental origin. The predominant clinical manifestations at the time of our assessment were inability to open her mouth. The most significant finding in the CT scan and in the Nuclear Magnetic Resonance Imaging (NMR) was the absence of the left parotid gland and the mandibular deformity with fusion of its posterior wall to the maxilla and left pterygoid process, with the consequent anterior displacement of the mandibular condyles due to severe dysplasia of the temporomandibular joint.
Given the clinical situation described, tracheotomy was required to proceed with the extrarticular release of the maxillomandibular ankylosis, extraction of the affected teeth and coverage with a standard mucosal flap. In the immediate postoperative period the buccal opening was fixed by 2 cm using a retromolar wedge.

At the present time the patient maintains a 2.4 cm buccomandibular opening, which allows solid oral feeding. Confirmation of this entity was made by anatomopathological study which reported changes compatible with chronic osteomyelitis.