Open Access Research article

Influence of temporomandibular disorder on temporal and masseter muscles and occlusal contacts in adolescents: an electromyographic study

Leandro Lauriti1, Lara Jansiski Motta2, Camila Haddad Leal de Godoy3, Daniela Aparecida Biasotto-Gonzalez3, Fabiano Politti3, Raquel Agnelli Mesquita-Ferrari4, Kristianne Porta Santos Fernandes4 and Sandra Kalil Bussadori4*

Author Affiliations

1 Oral Surgery, University Nove de Julho (UNINOVE), São Paulo, SP, Brazil

2 Paediatric Dentistry, University Nove de Julho (UNINOVE), São Paulo, SP, Brazil

3 Rehabilitation Sciences, University Nove de Julho (UNINOVE), Av. Divino Salvador, 638 - Moema, CEP: 04078-012 São Paulo, SP, Brazil

4 Master’s Course in Rehabilitation Sciences, University Nove de Julho (UNINOVE), São Paulo, SP, Brazil

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BMC Musculoskeletal Disorders 2014, 15:123  doi:10.1186/1471-2474-15-123

Published: 10 April 2014



The aim of the present study was to analyse the influence of temporomandibular disorder (TMD) on electromyographic activity in the masseter and temporal muscles of adolescents and investigate a possible association with the number of occlusal contacts.


The Helkimo Index was administered for the diagnosis of TMD and classification of the adolescents into three groups: without TMD; with mild TMD; and with moderate/severe TMD. Carbon paper was used for the determination of occlusal contact points. A standardised electromyographic evaluation was performed on the masticatory muscles at rest, during habitual chewing and during maximum voluntary clenching. The readings were normalised to maximum voluntary clenching. Statistical analysis involved the chi-squared test and Fisher’s exact test. The Kruskal-Wallis test and one-way analysis of variance with Dunn’s post hoc test were used to compare differences between groups. Pearson’s correlation coefficients (r) were calculated for the determination of correlations between the number of occlusal contacts and RMS values.


Electromyography revealed significant differences in the right and left masseter and temporal muscles at rest and during chewing among the three groups. These differences were not observed during maximum voluntary clenching. No statistically significant differences were found between the groups with and without TMD regarding the number of occlusal contacts.


Electromyographic activity in the masseter and temporal muscles was greater among adolescents with moderate to severe TMD.

Temporomandibular joint; Occlusion; Occlusal contacts; Electromyography