Facial nerve reconstruction and its prognosis.

Abstract

This study of the functional end results of successful surgical repair of the traumatized facial nerve trunk shows more or less homogenous results, whether the procedure was end-to-end suture or grafting, and independent of the site of the lesion. The expected results are: 1) excellent tonus at rest; 2) the ability to close the affected eye to a useful degree when the other eye is closed; 3) some ability to close the affected eye in association with some mass action of the affected face; 4) in a small proportion of patients, the ability to produce a faint smile, but not to move the corner of the mouth, to smile fully or to whistle; and 5) though all patients seemed to be able to move their faces “en masse,” none could move isolated groups of muscles as a healthy person can. Thus, though appreciable results are obtained, important limitations of movements are inevitable. The reason for these uniformly deficient results stems from the fact that in the facial nerve the peripheral axons are not arranged in a separate specific compartmental fashion. Instead, they intermingle and are distributed among the various bundles which constitute together the main nerve trunk; each bundle will therefore represent the whole face and not one specific region of the face. The result of this intermingling is that when axons regrow after traumatic repair, they have scarcely any chance to be redirected to their original regional muscular plate, due to inevitable crossover phenomena during regeneration.