title: Double-powered free gracilis muscle transfer for smile reanimation: A longitudinal optoelectronic study.
abstract: The choice of the motor donor nerve is a crucial point in free flap transfer algorithms. In the case of unilateral facial paralysis, the contralateral healthy facial nerve can provide coordinated smile animation and spontaneous emotional expression, but with unpredictable axonal ingrowth into the recipient muscle. Otherwise, the masseteric nerve ipsilateral to the paralysis can provide a powerful neural input, without a spontaneous trigger of the smile. Harvesting a bulky muscular free flap may enhance the quantity of contraction but esthetic results are unpleasant. Therefore, the logical solution for obtaining high amplitude of smiling combined with spontaneity of movement is to couple the neural input: the contralateral facial nerve plus the ipsilateral masseteric nerve. Thirteen patients with unilateral dense facial paralysis underwent a one-stage facial reanimation with a gracilis flap powered by a double donor neural input, provided by both the ipsilateral masseteric nerve (coaptation by an end-to-end neurorrhaphy with the obturator nerve) and the contralateral facial nerve (coaptation through a cross-face nerve graft: end-to-end neurorrhaphy on the healthy side and end-to-side neurorrhaphy on the obturator nerve, distal to the masseteric/obturator neurorrhaphy). Their facial movements were evaluated with an optoelectronic motion analyzer. Before surgery, on average, the paretic side exhibited a smaller total three-dimensional mobility than the healthy side, with a 52% activation ratio and >30% of asymmetry. After surgery, the differences significantly decreased (analysis of variance (ANOVA), p < 0.05), with an activation ratio between 75% (maximum smile) and 91% (maximum smile with teeth clenching), and <20% of asymmetry. Similar modifications were seen for the performance of spontaneous smiles. The significant presurgical asymmetry of labial movements reduced after surgery. The use of a double donor neural input permitted both movements that were similar in force to that of the healthy side, and spontaneous movements elicited by emotional triggering.
authors.affiliation: Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Laboratorio di Anatomia Funzionale dell'Apparato Locomotore (LAFAL), Dipartimento di Scienze Biomediche per la Salute, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, via Mangiagalli 31, I-20133 Milan, Italy. Electronic address: chiarella.sforza@unimi.it.
authors.forename: Chiarella
authors.initials: C
authors.lastname: Sforza
authors.affiliation: Human Physiology Section, Department of Pathophysiology and Transplantation, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, Milan, Italy; Carolyn and Peter Lynch Center for Laser and Reconstructive Surgery, Division of Facial Plastic and Reconstructive Surgery, Department of Otology and Laryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA.
authors.forename: Alice
authors.initials: A
authors.lastname: Frigerio
authors.affiliation: Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Laboratorio di Anatomia Funzionale dell'Apparato Locomotore (LAFAL), Dipartimento di Scienze Biomediche per la Salute, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, via Mangiagalli 31, I-20133 Milan, Italy; Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, School of Medicine, Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mapelli
authors.affiliation: Surgical Unit of Maxillo-Facial Surgery, San Paolo Hospital, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, Milan, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Tarabbia
authors.affiliation: Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Laboratorio di Anatomia Funzionale dell'Apparato Locomotore (LAFAL), Dipartimento di Scienze Biomediche per la Salute, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, via Mangiagalli 31, I-20133 Milan, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Annoni
authors.affiliation: Surgical Unit of Maxillo-Facial Surgery, San Paolo Hospital, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, Milan, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Colombo
authors.affiliation: Surgical Unit of Maxillo-Facial Surgery, San Paolo Hospital, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, Milan, Italy.
authors.forename: Mahfuz
authors.initials: M
authors.lastname: Latiff
authors.affiliation: Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Laboratorio di Anatomia Funzionale dell'Apparato Locomotore (LAFAL), Dipartimento di Scienze Biomediche per la Salute, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, via Mangiagalli 31, I-20133 Milan, Italy; Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, School of Medicine, Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Claudia L
authors.initials: CL
authors.lastname: Pimenta Ferreira
authors.affiliation: Surgical Unit of Maxillo-Facial Surgery, San Paolo Hospital, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, Milan, Italy.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Rabbiosi
authors.affiliation: Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Laboratorio di Anatomia Funzionale dell'Apparato Locomotore (LAFAL), Dipartimento di Scienze Biomediche per la Salute, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, via Mangiagalli 31, I-20133 Milan, Italy; Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, School of Medicine, Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
authors.forename: Fernanda V
authors.initials: FV
authors.lastname: Sidequersky
authors.affiliation: Functional Anatomy Research Center (FARC), Laboratorio di Anatomia Funzionale dell'Apparato Stomatognatico (LAFAS), Laboratorio di Anatomia Funzionale dell'Apparato Locomotore (LAFAL), Dipartimento di Scienze Biomediche per la Salute, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, via Mangiagalli 31, I-20133 Milan, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Zago
authors.affiliation: Surgical Unit of Maxillo-Facial Surgery, San Paolo Hospital, Facoltà di Medicina e Chirurgia, Università degli Studi di Milano, Milan, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Biglioli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D002648:Child; D004576:Electromyography; D004954:Esthetics; D005149:Facial Expression; D005152:Facial Muscles / Q000601:surgery; D005154:Facial Nerve / Q000254:growth & development / Q000503:physiopathology; D005158:Facial Paralysis / Q000601:surgery*; D058752:Free Tissue Flaps / Q000294:innervation; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000294:innervation / Q000637:transplantation*; D016067:Nerve Transfer; D019651:Plastic Surgery Procedures / Q000379:methods; D020127:Recovery of Function / Q000502:physiology*; D012904:Smiling / Q000502:physiology*; D013848:Thigh / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult
keywords: 3D; Asymmetry; Facial nerve paresis; Mimetics; Motion analysis