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


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 voluntary clenching. No statistically significant differences were found between the groups with and without TMD regarding the number of occlusal contacts.


CONCLUSIONS
Electromyographic activity in the masseter and temporal muscles was greater among adolescents with moderate to severe TMD.
Leandro
L
Lauriti
Lara Jansiski
LJ
Motta
Camila Haddad Leal
CH
de Godoy
Daniela Aparecida
DA
Biasotto-Gonzalez
Fabiano
F
Politti
Raquel Agnelli
RA
Mesquita-Ferrari
Kristianne Porta Santos
KP
Fernandes
Master's Course in Rehabilitation Sciences, University Nove de Julho (UNINOVE), São Paulo, SP, Brazil. sandra.skb@gmail.com.
Sandra Kalil
SK
Bussadori
D000293:Adolescent; D000367:Age Factors; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D003766:Dental Occlusion; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008406:Masseter Muscle / Q000503:physiopathology*; D008409:Mastication; D011237:Predictive Value of Tests; D015995:Prevalence; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013703:Temporal Muscle / Q000503:physiopathology*; D013705:Temporomandibular Joint Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology