[Regeneration of the severed facial nerve]

Twenty-four specimens from distal end of the human facial nerve obtained at reinnervation surgery (nerve grafting) were studied by light and electron microscopies. In 21 specimens, with complete severance of the facial nerve but continuous neurilemma confirmed during surgery, regeneration phenomenon was observed. Histological examination of the auricular branches of vagus nerve (2 cases) and auriculotemporal nerve (1 case) with their communication portion showed regeneration of axons into the facial nerve below the level of sectioning. This phenomenon points to the possibility that surgically interrupted communication branches may provide new endoneural tubes following inevitable degeneration of communication branches. These tubes facilitate motor axons growing through nerve graft.