Mandibular coronoid dislocation: a rare case report

We report a rare case of a non-traumatic mandibular dislocation irreducible by closed maneuvers due to entrapment of the coronoid process above the zygomatic arch in an elderly patient successfully treated with coronoidectomy. An 86-year-old man presented with an open-lock jaw that could not be reduced manually. Computed tomography (CT) revealed anterolateral displacement of the mandibular condyle with impaction of the coronoid process, superolaterally dislocated, against the zygomatic arch. Under general anesthesia, a coronoidectomy was performed using a piezoelectric device through an intraoral approach, which allowed spontaneous reduction of the condyle. Immediate restoration of occlusion and mandibular function was achieved after surgery, and at three months of follow-up the patient showed a maximum mouth opening (MMO) of 40 millimeters, stable occlusion, and no evidence of recurrent dislocation. This case indicates that coronoidectomy can represent an effective and safe treatment option to relieve mechanical impingement in irreducible mandibular dislocations associated with coronoid process displacement, particularly in elderly patients.