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

• Grant number: 14/06368-2
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: April 01, 2014
• End date: September 30, 2014
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Sandra Kalil Bussadori
• Grantee: Sandra Kalil Bussadori
• Host Institution: Universidade Nove de Julho (UNINOVE). Campus Vergueiro. São Paulo , SP, Brazil

Abstract

Background: 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. Methods: 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 intercuspation. 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. Results: 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 intercuspation. No statistically significant differences were found between the groups with and without TMD regarding the number of occlusal contacts. Conclusion: Electromyographic activity in the masseter and temporal muscles was greater among adolescents with moderate to severe TMD. (AU)