Abstract
Pseudoankylosis is an uncommon condition characterized by painless restriction of jaw mobility. It is a pathological condition outside the temporomandibular joint (TMJ) articular structure, with myogenic, osteologic, neurogenic, and psychogenic etiologies. The authors present a case of pseudoankylosis arising as an isolated complication of reanimation with neuro-vascular anastomosed gracilis muscle.
1
Introduction
Pseudoankylosis is a painless condition, the predominant symptom being limited jaw mobility. It is a pathological condition outside the TMJ articular structure that may be of myogenic, osteologic, neurogenic, or psychogenic etiology [ , ]. It can arise as a result of trauma in the region of the muscular process, the mastoid process, or the jaw bone, as a result of surgery (transcoronal surgery, temporoparietal craniotomy), oncological lesions, or radiotherapy. Other causes include idiopathic hyperplasia of the coronoid process and congenital fusion of the maxilla and mandible [ ]. The authors present a case of pseudoankylosis arising as an isolated complication of reanimation with neuro-vascular anastomosed gracilis muscle.
2
Case presentation
A 27-year-old female patient presented to our clinic with several years of restricted, painless jaw mobility. The maximum interincisal opening (MIO) was 4 mm. Protrusion and laterotrusion were not possible. Clinical examination revealed a pathological mass retromaxillary on the right side. A CT scan showed a bony connection between the zygoma and the mandibular ramus ( Figs. 1 and 2 ). The patient’s history revealed that in 2012, at age 17, she suffered a hemorrhage from a brainstem cavernoma, with subsequent right-sided facial and abducens nerve paresis and mild left-sided hemiparesis. In 2014, she underwent microsurgical reanimation of the right facial nerve using a neuro-vascular anastomosed gracilis muscle flap. Post-operatively, a significant hematoma required surgical wound revision during the first week. In 2016, a revision of the right cheek was performed via an intraoral approach due to progressive restricted jaw mobility. This was followed by repeated rehabilitation, with no effect. The patient presented to our department in 2022. Based on the clinical symptoms and CT scan, a diagnosis of pseudoankylosis resulting from gracilis muscle flap facial nerve reanimation was made. The condition was resolved via an intraoral approach by removing the bony connection. The space was filled with a pedicled buccal fat pad. The patient was hospitalized for five days post-operatively for intensive rehabilitation. Rehabilitation to improve mouth opening began on the first post-operative day. In the first week, mouth opening improved to 20 mm (interincisally). Three months post-operatively, MIO was 35 mm; six months, 37 mm; and one year, 41 mm.
