[Facial nerve paralysis and mandibular fracture]

The authors describe three cases of peripheral facial nerve paralysis in patients with a mandibular fracture. In two cases, in which the onset of palsy was uncertain, the facial nerve injury was contralateral to the fractured side. Topodiagnostic tests showed neural damage at the third intrapetrosal portion and at the genicular ganglion. In one of the two patients tomography revealed a fracture line through the anterio-superior wall of the external auditory canal homolateral to the facial palsy. In the third subject palsy set in immediately after the trauma and was ipsilateral to the mandibular fracture; the facial lesion was localized at the genicular ganglion. In the first two cases, functional recovery was spontaneous (40 and 0 days after the trauma respectively). In the third subject, the nerve was decompressed surgically with a complete functional recovery two months later. The functional and clinical findings of these three cases show that a contralateral facial palsy secondary to a mandibular fracture resolves spontaneously while the traumatic displacement of the mandibular condyle may determine a temporal bone fracture sometimes followed by a lesion in the intratemporal portion of the facial nerve. An event such as the latter may delay functional recovery and thus warrant surgery such as in cases of Bell's palsy.