Pseudoankylosis Between Lateral Pterygoid Plates and Mandible: Report of One Case.

Temporomandibular joint (TMJ) ankylosis is the abnormal fusion of TMJ anatomic components that impedes free jaw movements. This restriction in motion ranges from minimal to a complete inability to open the jaw. This condition can be categorized as true ankylosis, which is attributed to pathologic conditions of the TMJ, or false ankylosis (pseudoankylosis), which describes restrictions of movement resulting from extracapsular abnormalities outside the TMJ. The literature shows that trauma is the leading cause of TMJ disorders and appears to be the most common cause of pseudoankylosis. Pseudoankylosis caused by pterygomandibular bony impingement has rarely been reported in the literature. This case report adds a new case of pseudoankylosis to the existing scanty literature, which was characterized by bilateral mechanical impingement between abnormally elongated lateral pterygoid plates and the coronoid processes of the mandible.