Mandibular Condyle Dislocation Into the Middle Cranial Fossa: A Case Report and Review of Literature

Abstract

Impact to the mandible typically results in ipsilateral or contralateral condylar neck fractures. Fracture of the glenoid fossa with a mandibular condyle dislocation into the middle skull base is a rare event. Structural variance is considered to be the determinant for this kind of fracture. Steinhauser proved experimentally that the central part of the glenoid fossa is the weakest part of the skull base. Normally, the lateral and medial elevated margins of the glenoid fossa meet the articular surface, that is the medial and lateral pole, of the mandibular condyle on impact. Da Fonseca remarked that a rounded condyle without any accentuated medial or lateral poles creates a higher pressure onto the bone of the glenoid fossa compared with a scroll shape. The role of the presence of occluding posterior teeth preventing the burst of the glenoid fossa by blocking the upward mandibular thrust, however, is controversial, according to other research. Victims of high-speed accidents with their mouths open who sustain a sudden blow to the chin may possibly be predisposed to undergo these injuries. Until today, only 30 cases have been reported, upon reviewing the English literature, with the first case being reported by Dingman and Grabb in 1963. Among the various nomenclature of this type of injury the term “central dislocation” is spread. Other central dislocations might occur in the hip joint with an intrapelvic dislocation of the femoral head or in the shoulder joint with an intrathoracic dislocation of the humeral head. Clinical features can include preauricular pain, laterognathism, and a limited range of motion without specific neurological signs or symptoms. These often may be misdiagnosed because of joint edema, joint “dislocation,” or radiographically poorly defined subcondylar fractures. Missed or delayed diagnosis of this injury may, therefore, occur. In addition to that, mortality because of intracranial damage from a displaced condyle or from other concomitant cranial injuries might explain the low number of cases reported. Intracranial hematomas, facial nerve paralysis or paresis –22 combined with a unilateral and bilateral cranial base fracture, damages of the eighth cranial nerve with ipsilateral hearing loss, hematorrhoea, leakage of cerebrospinal fluid, and cerebral injuries as contusion or concussion are some of the other findings reported in literature. Because of the complexity of these injuries, a variety of treatment options has been reported in the literature. The overall aim of any treatment, however, is both to prevent additional neurological problems and to obtain a proper occlusion, thus restoring function to avoid future temporomanqibular joint disorders like, for example, ankylosis. This article presents the case of a 9-year-old girl who fell down from a climbing pole in a local playground. The impact on the chin caused a dislocation of the right mandibular condyle into the middle cranial fossa. The treatment and the follow-up of this case is reported to add to the small number of previous case reports and to hopefully be useful for future case management.