[Accident-induced lesions of the facial nerve in relation to the extent of pyramidal pneumatization].

Perilabyrinthine pneumatisation of the petrous pyramid constitutes a risk factor for the facial nerve in its labyrinthine part in a fracture of the temporal bone because serious splintering of bone is possible. Splinters dislocated into the Fallopian canal may damage the nerve seriously. On the other hand a perineural haematoma can flow out of the canal into the neighbouring cells through dehiscences or through the fractured canal walls and a compression of the nerve may be avoided. The decision to undertake early surgical intervention must take into account the degree of pneumatisation of the pyramid in posttraumatic lesions of the facial nerve. The timing and extent of recovery cannot be predicted.