title: Impaired orofacial motor functions on chronic temporomandibular disorders.
abstract: Because temporomandibular disorders (TMDs) rehabilitation continues to be a challenge, a more comprehensive picture of the orofacial functions in patients with chronic pain is required. This study assessed the orofacial functions, including surface electromyography (EMG) of dynamic rhythmic activities, in patients with moderate-severe signs and symptoms of chronic TMD. It was hypothesized that orofacial motor control differs between patients with moderate-severe chronic TMD and healthy subjects. Seventy-six subjects (46 with TMD and 30 control) answered questionnaires of severity of TMD and chewing difficulties. Orofacial functions and EMG during chewing were assessed. Standardized EMG indices were obtained by quantitative analysis of the differential EMG signals of the paired masseter and temporal muscles, and used to describe muscular action during chewing. TMD patients showed significant greater difficulty in chewing; worse orofacial scores; longer time for free mastication; a less accurate recruitment of the muscles on the working and balancing sides, reduced symmetrical mastication index (SMI) and increased standardized activity during EMG test than healthy subjects. SMI, TMD severity and orofacial myofunctional scores were correlated (P<0.01). Impaired orofacial functions and increased activity of the muscles of balancing sides during unilateral chewing characterized the altered orofacial motor control in patients with moderate-severe chronic TMD. Implications for rehabilitation are discussed.
authors.affiliation: Department of Otorhinolaryngology, Ophthalmology, and Head and Neck Surgery, School of Medicine, Ribeirão Preto, University of São Paulo, Brazil; Craniofacial Research Support Centre, University of São Paulo, Brazil.
authors.forename: Cláudia Lúcia Pimenta
authors.initials: CL
authors.lastname: Ferreira
authors.affiliation: Department of Otorhinolaryngology, Ophthalmology, and Head and Neck Surgery, School of Medicine, Ribeirão Preto, University of São Paulo, Brazil; Craniofacial Research Support Centre, University of São Paulo, Brazil.
authors.forename: Bárbara Cristina Zanandréa
authors.initials: BC
authors.lastname: Machado
authors.affiliation: Department of Otorhinolaryngology, Ophthalmology, and Head and Neck Surgery, School of Medicine, Ribeirão Preto, University of São Paulo, Brazil; Craniofacial Research Support Centre, University of São Paulo, Brazil.
authors.forename: Carina Giovana Pissinatti
authors.initials: CG
authors.lastname: Borges
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo, Brazil; Craniofacial Research Support Centre, University of São Paulo, Brazil.
authors.forename: Marco Antonio M
authors.initials: MA
authors.lastname: Rodrigues Da Silva
authors.affiliation: Functional Anatomy Research Center (FARC), Laboratory of Functional Anatomy of the Stomatognathic Apparatus, Dipartimento di Scienze Biomediche per la Salute, Faculty of Medicine, Università degli Studi di Milano, Italy.
authors.forename: Chiarella
authors.initials: C
authors.lastname: Sforza
authors.affiliation: Department of Otorhinolaryngology, Ophthalmology, and Head and Neck Surgery, School of Medicine, Ribeirão Preto, University of São Paulo, Brazil; Craniofacial Research Support Centre, University of São Paulo, Brazil. Electronic address: claudiafelicio@gmail.com.br.
authors.forename: Cláudia Maria
authors.initials: CM
authors.lastname: De Felício
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D011795:Surveys and Questionnaires; D013703:Temporal Muscle / Q000503:physiopathology*; D013705:Temporomandibular Joint Disorders / Q000503:physiopathology*
keywords: Electromyography; Mastication; Orofacial myofunctional evaluation; Temporomandibular disorders