Is the Masticatory Function Changed in Patients with Temporomandibular Disorder?

Abstract

Patients with temporomandibular disorders (TMD) often complain and have limitation in masticatory function, which can be affected by a complex interaction of factors. The aim of this study was analyze the masticatory function in patients with TMD using surface electromyography (EMG) and masticatory efficiency (ME). Twenty-seven patients with TMD and 25 considered control (n), aged between 18 and 60 years, paired by age and gender, were evaluated according to RDC/TMD. In both groups were performed: EMG with chewing gum, clinical evaluation of habitual chewing with stuffed cookie (CE) (number of chewing strokes and time) and analysis of ME with fuchsin beads. Nonparametric statistical analyses were used (Mann-Whitney) for comparisons between groups, with 5% significance level. For all variables, the TMD group showed higher values than the control, with statistical significance for ME (p<0.0001), number of chewing strokes (p=0.04), chewing time (p=0.009), right masseter EMG activity (p=0.05), left masseter (p=0.005), right anterior temporal (p=0.05) and left anterior temporal (p=0.001). The conclusion is that patients with TMD showed changed chewing pattern, but without impairment of masticatory function.

Association between chewing dysfunctions and temporomandibular disorders: A systematic review

“…From the 17 selected studies, fifteen of them used RDC/TMD protocol for TMD diagnosis and the other two studies used the Helkimo Protocol . The studies which used RDC/TMD protocol presented a sample with only masticatory muscles disorders, a sample with mixed TMD, a sample with the 3 subtypes of TMD (TMJ disorders, masticatory muscles disorders or mixed), samples with TMJ disorders and mixed TMD, and samples with only mixed TMD . Regarding two articles that used Helkimo Protocol, one of them presented a sample with minor, moderate, and severe TMD, and the other presented a sample with moderate and severe TMD.…”

“…Regarding two articles that used Helkimo Protocol, one of them presented a sample with minor, moderate, and severe TMD, and the other presented a sample with moderate and severe TMD. Studies which used RDC/TMD were conducted in Brazil, Chile, Italy and United States, whilst studies which used Helkimo Protocol were conducted in Mexico and Spain . A summary of the studies descriptive characteristics can be found in Table and the sEMG characteristics are available in Table .…”

“…However, there are different ways in the literature to classify and identify what is a chewing dysfunction. One method that can be used to assess the chewing process is surface electromyography (sEMG) . Surface electromyography is able to measure the electrical potential generated by the muscles fibres, through a pair of surface electrodes attached to the skin just above the masticatory muscles .…”

Atuação fonoaudiológica em disfunção temporomandibular em dois casos: análise comparativa dos efeitos da terapia tradicional e o uso da bandagem terapêutica associada

“…Fazem parte de um espectro de síndromes associadas ao estresse e são caracterizados por fatores ambientais e psicológicos 3 , incluindo fadiga, prejuízo das atividades do trabalho e escola, distúrbios do sono e do apetite/alimentação, ansiedade e depressão 4. A etiologia das disfunções da ATM é multifatorial 5 e os fatores que contribuem para o desenvolvimento das mesmas incluem má oclusão, fatores traumáticos, doenças sistêmicas, hábitos parafuncionais 6 , alterações posturais e stress e ansiedade 7 . Sabe-se que os sinais e sintomas mais observados em pacientes com DTM são limitações da amplitude de movimentos mandibulares, dor ou desconforto, ruído articular, dificuldade na mastigação e cefaleia (8)(9)(10)(11) . A DTM tem sido identificada como a primeira causa de dor não dental em região orofacial 4 .…”

Incidence of Temporomandibular Disorders Among Dental Students

“…7 For the assessment of TMD according to the applicability and researcher or clinician purposes, questionnaires, imaging tests such as x-rays, computed tomography, magnetic resonance imaging and clinical assessment has been used. 8 The research diagnostic criteria for TMD standardize the diagnosis and classification of clinical forms of TMD.…”