Temporal bone findings in hemifacial microsomia.

The temporal bone findings in a case of hemifacial microsomia are described with photographs. The right facial hypoplasia was associated with anophthalmia and microtia on the same side. The right petrous bone was hypoplastic and showed total superior dehiscence of the internal acoustic meatus. Th otic capsule was deformed with an underdeveloped cochlear modiolus grossly deficient in spiral ganglion population. The spiralling cochlear shell showed partial deficiency of the interscalar septum between the middle and apical coils. The cochlear duct was shorter than that on the normal side; the organ of Corti however was normal. The vestibular system did not show any structural abnormality except for the degeneration and reduction of the Scarpa's ganglion cells and nerve fibers. An additional interesting fact was that the facial nerve was totally absent in the temporal bone except for its nervus intermedius component.