Revista Dental Press de Ortodontia e Ortopedia Facial
Print version ISSN 1415-5419
PIGNATARO NETO, Godofredo; BERZIN, Fausto and RONTANI, Regina Maria Puppin. Masticatory preference side detection using electromyography exam compared to the visual analysis. Rev. Dent. Press Ortodon. Ortop. Facial [online]. 2004, vol.9, n.4, pp. 77-85. ISSN 1415-5419. http://dx.doi.org/10.1590/S1415-54192004000400008.
The objective of this study was to verify the frequency of masticatory preferential side using electromyography exam compared to the visual inspection. The sample was comprised by 29 healthy students aged 18 to 25 years, of both sexes, from Araras School of Dentistry-UNIARARAS, Brazil, selected following approach: complete permanent dentition, except third molars, with no clinical signs of the temporomandibular dysfunction or periodontal disease. The electromyography analysis was accomplished in the right and left masseter muscles during habitual mastication of carrot and Parafilm. It was considered as presence on a masticatory preferential side and unilateral mastication when the muscular contraction width values obtained in RMS (Root Mean Square) has had at least 20% as a difference between the right and left masseter muscles. The visual inspection was carried out during the electromyography data acquisitions by only one observer. He determined the masticatory preferential side taking account the number of masticatory cycles developed by each side. The masticatory preferential side was considered when 30% of the cycles were developed in only one side after the registration of 20 consecutive masticatory cycles. Of the total sample, 82.8% (24/29) and 72.4% (21/29) exhibited a preferential masticatory side during habitual carrot and Parafilm mastication, respectively. The concordance level between the electromyography and visual inspection exams was 83% of the total observations. It could be concluded that most of the subjects examined in this study exhibited a masticatory preferential side and that the electromyography can be used as a parameter for the masticatory side detection.
Keywords : Mastication; Masticatory preference side; Unilateral mastication; Electromyography.