Effect of facial vertical pattern on mastication and its parameters / Influencia do padrão facial vertical sobre a mastigação e seus parametros

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

Craniofacial vertical morphology may influence the disposition of masticatory muscles, affecting some functions of stomatognathic system. Thus, the aims of this study were to evaluate, in subjects with different facial vertical pattern, the quality of mastication and the following masticatory parameters: occlusal contact area, muscles activities, muscle effort, mandibular movement, lateral asymmetries and chewing side preference. Seventy-eight healthy and dentate individuals were selected according to facial vertical pattern, which was determined using VERT index: (1) mesofacial, (2) brachyfacial, (3) dolichofacial. Quality of mastication was determined by masticatory efficiency and masticatory performance indexes, using a silicon based test material and a system composed by 10 sieves. Masticatory efficiency was calculated by the percentage of comminuted material up to 2 mm, and masticatory performance was given by the X50 value, which was obtained by the Rosin-Rammler equation. Occlusal contact area was evaluated bilaterally using silicon casting of occlusal surfaces and analysis of scanned image with appropriate software. Electromyographic activity of masseter and anterior temporal muscles was carried out at rest, during maximal vertical clenching and during mastication. Muscles effort of masticatory muscles was determined by the percentage of activity used for mastication in relation to the maximal muscle activity. Mandibular movements and chewing side preference were evaluated using a jaw-tracking device. For determination of lateral asymmetries, maximal bite force and occlusal contact area were analysed unilaterally by means of sensors positioned in first molar region and silicon cast, respectively. Data were analyzed using carefully selected statistics methods at a 5% significant level. Dolichofacial subjects presented lower values of masticatory efficiency, masticatory performance, bilateral occlusal contact area, muscle activity at rest and during maximal vertical clenching followed by mesofacial and brachyfacial subjects. Dolichofacials also presented maximal bite force asymmetry, as well as accomplished larger muscle effort and mandibular posterior movement, both during chewing. No significant difference was found among groups for muscle activity during mastication and chewing side preference. All groups presented occlusal contact area asymmetry, with larger area at left side. In the terms in which this study was performed, it can be concluded that craniofacial morphology influences masticatory function and its parameters.

ASSUNTO(S)

movement mandibula movimento mandible masticatory muscles musculos mastigatorios

ACESSO AO ARTIGO

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