Pterygomandibular ankylosis : a report on two cases

Abstract

Pseudo-ankylosis of the temporo-mandibular joint (TMJ) refers to a persistent restricted mandibular hypomobility resulting from a pathologic condition outside the TMJ. Ankyloses may be acquired or congenital. Most congenital ankyloses are extracapsular (pseudo- ankyloses), while most of the acquired ankyloses (true ankyloses) are intracapsular. An extremely rare form of extracapsular ankylosis is bony pterygomandibular fusion, few cases having been reported in the literature. To our knowledge, a case with two separate ipsilateral extracapsular ankylosis sites together with bilateral intracapsular ankylosis has never been reported. This paper considers the case of a 24 year-old patient who had been unable to open his mouth for six years. There was neither a history of trauma nor one of recurrent infection. The patient presented with a slight facial asymmetry with deviation of the mandible towards the right. CT scans confirmed the diagnosis of a complex pseudoankylosis, characterised by unilateral bony fusions between the lateral pterygoid plate and the medial aspect of the ramus, coronoid process and zygoma together with bilateral intracapsular ankyloses. The patient underwent surgery for ostectomy of the pterygomandibular fusion and a bilateral coronoidectomy. Comments on a paediatric case with bilateral bony pterygomandibular fusions are also included.