Differences between sexes in dissociation and spontaneity of smile in facial paralysis reanimation with the masseteric nerve.

BACKGROUND A patient's sex is likely to play an important role in facial paralysis reanimation, with women being superior in terms of development of brain plasticity after reanimation. The purpose of this study was to compare the rate of movement dissociation and spontaneity of men versus women reanimated with gracilis transfer neurotized to the masseteric nerve. METHODS We conducted a retrospective chart review of 27 patients who underwent facial paralysis reanimation with microvascular gracilis transplants neurotized to the ipsilateral masseteric nerve. Patients were classified by sex, comparing age at surgery, denervation time, and follow-up, as well as the rates of movement dissociation and smile spontaneity. RESULTS After reanimation with gracilis to masseteric nerve, movement dissociation and spontaneity were higher in women during the first year after onset of facial movement (p=.02 and p=.01, respectively). CONCLUSION After reanimation with masseteric nerve, women seem to be able to smile spontaneously and independently from teeth clenching earlier than men.