Effect of different dental articulating papers on SEMG activity during maximum clenching

This study evaluated the influence of two different occlusal indicators (articulating papers of 40μm and 200μm) on muscular activity of the temporalis anterior (TA) and superficial masseter (MS) during maximum voluntary clenches (MVC), using surface electromyography (SEMG). It was hypothesized that an articulating paper positioned between dental arches during MVC elicits a different muscular activity compared with the occlusion on natural dentition (without the occlusal indicator). 30 healthy adult subjects with a complete, natural dentition were recruited; SEMG activity was recorded in the following experimental conditions: MVC with cotton rolls for standardization purposes; MVC on natural dentition; MVC onto the 40 μm or 200μm paper indicator positioned on right or left side of the dental arch. Percentage Overlapping Coefficient (POC; separate values obtained for TA and MS), antero-posterior coefficient (APC) and total muscle activities (IMP) were the analyzed SEMG parameters. The use of an occlusal indicator statistically changed POC_TA, POC_MS and IMP median values (p < 0.05). Both 40μm and 200μm occlusal papers did not significantly affect APC values (P=0.86). A pronounced asymmetric muscular activity has been recorded with the introduction of an interocclusal media. All indices of muscular activity did not differ between sexes (Kruskal Wallis test, P > 0.05). In conclusion, the examined articulating papers affected two specific SEMG parameters (POC and IMP); the recorded muscular activity with the occlusal indicator varied regardless left or right side positioning, and independently from tested paper thicknesses.