Workhorse Free Functional Muscle Transfer Techniques for Smile Reanimation in Children with Congenital Facial Palsy: Case Report and Systematic Review of the Literature

Abstract

Background: Pediatric facial palsy represents a rare multifactorial entity. Facial reanimation restores smiling, thus boosting self-confidence and social integration of the affected children. The purpose of this paper is to present a systematic review of microsurgical workhorse free functional muscle transfer procedures with emphasis on the long-term functional, aesthetic, and psychosocial outcomes.

Materials and methods: We performed a literature search of the PubMed database from 1995 to 2019 using the following search strategy: "facial paralysis"[Title/Abstract] OR "facial palsy"[Title]. We used as limits: full text, English language, age younger than 18 years, and humans. Two independent reviewers performed the online screening process using Covidence. Forty articles met the inclusion criteria. The protocol was aligned with the PRISMA statement (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and was registered at the International Prospective Register of Systematic Reviews (PROSPERO, CRD42019150112) of the National Institute for Health Research.

Results: Free functional muscle transfer procedures include mainly segmental gracilis, latissimus dorsi, and pectoralis minor muscle transfer. Facial reanimation procedures with the use of the cross-face nerve graft (CFNG) or masseteric nerve result in almost symmetric smiles. The transplanted muscle grows harmoniously along with the craniofacial skeleton. Muscle function and aesthetic outcomes improve over time. All children presented improved self-esteem, oral commissure opening, facial animation, and speech.

Conclusions: A two-stage CFNG plus an FFMT may restore a spontaneous emotive smile in pediatric facial palsy patients. Superior results of children FFMT compared to adults FFMT are probably attributed to greater brain plasticity.

Keywords: Moebius syndrome; Smile reanimation; facial paralysis; free functional muscle transfer; long-term outcomes; pediatric.