Qualitative and Quantitative Analysis of Smile Excursion in Facial Reanimation: A Systematic Review and Meta-analysis of 1- versus 2-stage Procedures

Abstract

Background:Free functional muscle transfer has become a common treatment modality for smile restoration in long-lasting facial paralysis, but the selection of surgical strategy between a 1-stage and a 2-stage procedure has remained a matter of debate. The aim of this study was to compare the quantitative and qualitative outcomes of smile excursion between 1-stage and 2-stage free muscle transfers in the literature.Methods:A comprehensive review of the published literature between 1975 and end of January 2017 was conducted.Results:The abstracts or titles of 2,743 articles were screened. A total of 24 articles met our inclusion criteria of performing a quantitative or qualitative evaluation of a free-functioning muscle transfer for smile restoration. For the purpose of meta-analysis, 7 articles providing quantitative data on a total of 254 patients were included. When comparing muscle excursion between 1-stage and 2-stage procedures, the average range of smile excursion was 11.5 mm versus 6.6 mm, respectively. For the purpose of systematic review, 17 articles were included. The result of the systematic review suggested a tendency toward superior functional results for the 1-stage procedure when comparing the quality of smile.Conclusions:The results of this review must be interpreted with great caution. Quantitative analysis suggests that 1-stage procedures produce better excursion than 2-stage procedures. Qualitative analysis suggests that 1-stage procedures might also produce superior results when based on excursion and symmetry alone, but these comparisons do not include one important variable dictating the quality of a smile—the spontaneity of the smile. The difficulty in comparing published results calls for a consensus classification system for facial palsy.

Novel Method of Dual-innervated Free Gracilis Muscle Transfer for Facial Reanimation: A Case Series

“…Our findings of 7.6 mm of excursion are comparable and slightly improved to previously reported excursion values of 6.6 mm for CFNG. 7,42 Our excursions during biting are slightly lower than the reported value of around 11 mm for masseteric only innervation 42 likely due to our additional nerve graft, or by chance given the low patient numbers. An interesting future animal model would be to perform a dual-innervated muscle transfer, then eliminate one innervation source and see if the previously dualinnervated muscle maintained stronger force than the single innervated muscle just due to muscle mass preservation.…”

Acute Peripheral Facial Palsy: Recent Guidelines and a Systematic Review of the Literature

“…The candidates for muscle transfer include the pectoralis minor, latissimus dorsi, serratus anterior, external digitorium brevis, rectus abdominis, and the gracilis. 33 In accordance with the donor nerve, a single-stage (using an ipsilateral non-facial cranial nerve, such as the masseter nerve, spinal accessory nerve, or hypoglossal nerve), or a two-stage surgery, which consists of a first-stage cross-facial nerve grafting and a second-stage free muscle transfer, are employed for facial reanimation. 33 When comparing single-stage with two-staged operations, single-stage operations have tended to yield better smile reanimations.…”

“… 33 When comparing single-stage with two-staged operations, single-stage operations have tended to yield better smile reanimations. 33 …”

Evaluation of the Patient with Facial Palsy: A Multidisciplinary Approach

“…65,66 Free muscle transfers can be either a single innervation 64 (ipsilateral motor nerve use, such as the masseteric nerve) or a dual innervation 67 (contralateral cross over graft, such as the contralateral facial nerve). Combination muscle flaps have also been described with promising results and may be performed as single-or dual-stage procedures.58, 68 Surgical outcomes are enhanced by ongoing rehabilitation and results may take up to 2 years to achieve. 58 The choice of surgical technique in any center is likely to be influenced by local training, subspeciality and expertise.…”