Reestablishment of the Smile after Hypoglossal–Facial Nerve Transfer: What Can We Learn?

Abstract

Objective: To assess the ability to smile following hypoglossal-facial nerve transfer (N12-N7). Design: Retrospective chart review. Setting: National tertiary referral center for skull base pathology. Participants: Seventeen patients Main outcome measures: The ability to smile following N12-N7 transfer was assessed by five medical doctors on photos of the whole face and frontal, orbital and oral segments. The (segmented) photos were scored: symmetrical, asymmetrical, correct or incorrect assessment of affected side. Results: Seventeen patients were analysed by 5 assessors providing 85 assessments. The whole face in rest was judged symmetrical in 26% of the cases, and mildly asymmetrical in 56%. Frontal, orbital, and oral segments were symmetrical in 63, 20 and 35% respectively. The affected side was correctly identified in 76%. When smiling, the whole face was symmetrical in 6% and mildly asymmetric in 59%. The affected side was correctly identified in 94%. The frontal, orbital, and oral segments during smiling were symmetrical in 67, 15 and 6%, respectively. The affected side of the frontal, orbital and buccal facial segments during smiling was correctly identified in 89, 89 and 96%, respectively. Interobserver variability with Fleiss Kappa analysis showed that the strength of agreement during smile of the total face was good (0.771) Conclusions: Following N12-N7 transfer a good facial symmetry in rest can be achieved. During smiling, almost all patients showed asymmetry of the face which was predominantly determined by orbital and oral segments. To improve the ability to smile after N12-N7 transfer additional procedures are needed.