APS 1995 Presidential address

Abstract

In this study, facial symmetry was compared between the masseter-innervated and dual-innervated free multivector serratus anterior muscle transfer (FMSAMT).Sixteen patients with unilateral complete facial paralysis underwent facial reanimation surgery from April 2006 to July 2019. The masseter-innervated FMSAMT group (Group M, n=6) underwent end-to-end coaptation with the ipsilateral masseter nerve in one-stage. The dual-innervated FMSAMT group (Group D, n=10) underwent end-to-end coaptation with the masseter nerve and end-to-side coaptation with the contralateral facial nerve via cross-facial nerve graft. They were further divided into one-stage subgroup (Group D1, n=5) and two-stage subgroup (Group D2, n=5). The period until the first visible muscle contraction with clenching, the first spontaneous smile, and completion of resting tone were evaluated. The possibility of spontaneous smile and symmetry of the midline and horizontal deviation at rest and during voluntary smiling were compared between each group.Group M and Group D differed significantly in the possibility of spontaneous smile and in the improvement rate of midline deviation and horizontal deviation at rest (p<0.001, p<0.001, and p=0.001, respectively), but not in the improvement rate of midline and horizontal deviation during voluntary smiling. The period until the completion of resting tone occurred significantly earlier in Group D1 than in Group D2 (p = 0.048); however, the possibility of spontaneous smile and the improvement rate of midline and horizontal deviation were not significantly different.One-stage dual-innervated FMSAMT was effective in guaranteeing a symmetrical resting tone, voluntary smiling, and in reproducing a spontaneous smile.