Andrea Mapelli1, Bárbara Cristina Zanandréa Machado1, Lucia Dantas Giglio1, Chiarella Sforza2, Cláudia Maria De Felício3. 1. 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. 2. 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. 3. 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: cfelicio@fmrp.usp.br.
Abstract
OBJECTIVE: To investigate whether reorganization of muscle activity occurs in patients with chronic temporomandibular disorders (TMD) and, if so, how it is affected by symptomatology severity. METHODS: Surface electromyography (sEMG) of masticatory muscles was made in 30 chronic TMD patients, diagnosed with disc displacement with reduction (DDR) and pain. Two 15-patient subgroups, with moderate (TMDmo) and severe (TMDse) signs and symptoms, were compared with a control group of 15 healthy subjects matched by age. The experimental tasks were: a 5s inter-arch maximum voluntary clench (MVC); right and left 15s unilateral gum chewing tests. Standardized sEMG indices characterizing masseter and temporalis muscles activity were calculated, and a comprehensive functional index (FI) was introduced to quantitatively summarize subjects' overall performance. Mastication was also clinically evaluated. RESULTS: During MVC, TMDse patients had a significantly larger asymmetry of temporalis muscles contraction. Both TMD groups showed reduced coordination between masseter and temporalis muscles' maximal contraction, and their muscular activity distribution shifted significantly from masseter to temporalis muscles. During chewing, TMDse patients recruited the balancing side muscles proportionally more than controls, specifically the masseter muscle. When comparing right and left side chewing, the muscles' recruitment pattern resulted less symmetric in TMD patients, especially in TMDse. Overall, the functional index of both TMDmo and TMDse patients was significantly lower than that obtained by controls. CONCLUSIONS: Chronic TMD patients, specifically those with severe symptomatology, showed a reorganized activity, mainly resulting in worse functional performances.
OBJECTIVE: To investigate whether reorganization of muscle activity occurs in patients with chronic temporomandibular disorders (TMD) and, if so, how it is affected by symptomatology severity. METHODS: Surface electromyography (sEMG) of masticatory muscles was made in 30 chronic TMDpatients, diagnosed with disc displacement with reduction (DDR) and pain. Two 15-patient subgroups, with moderate (TMDmo) and severe (TMDse) signs and symptoms, were compared with a control group of 15 healthy subjects matched by age. The experimental tasks were: a 5s inter-arch maximum voluntary clench (MVC); right and left 15s unilateral gum chewing tests. Standardized sEMG indices characterizing masseter and temporalis muscles activity were calculated, and a comprehensive functional index (FI) was introduced to quantitatively summarize subjects' overall performance. Mastication was also clinically evaluated. RESULTS: During MVC, TMDse patients had a significantly larger asymmetry of temporalis muscles contraction. Both TMD groups showed reduced coordination between masseter and temporalis muscles' maximal contraction, and their muscular activity distribution shifted significantly from masseter to temporalis muscles. During chewing, TMDse patients recruited the balancing side muscles proportionally more than controls, specifically the masseter muscle. When comparing right and left side chewing, the muscles' recruitment pattern resulted less symmetric in TMDpatients, especially in TMDse. Overall, the functional index of both TMDmo and TMDse patients was significantly lower than that obtained by controls. CONCLUSIONS: Chronic TMDpatients, specifically those with severe symptomatology, showed a reorganized activity, mainly resulting in worse functional performances.
Authors: Michał Ginszt; Jacek Szkutnik; Grzegorz Zieliński; Magdalena Bakalczuk; Małgorzata Stodółkiewicz; Monika Litko-Rola; Apolinary Ginszt; Mansur Rahnama; Piotr Majcher Journal: Int J Environ Res Public Health Date: 2022-01-29 Impact factor: 3.390
Authors: Michał Ginszt; Grzegorz Zieliński; Jacek Szkutnik; Marcin Wójcicki; Michał Baszczowski; Monika Litko-Rola; Ingrid Rózyło-Kalinowska; Piotr Majcher Journal: J Clin Med Date: 2022-01-07 Impact factor: 4.241