Occlusal force has the main role in determining the teeth health in general and determining the chewing, muscle and TMJ function. The objective of this study was to find if there was any relation between the preferred chewing side and the force, measured by T-scan III system. The total number of 90 (46 female and 44 male) dental students was included in this study. They were asked whether their preferred chewing side was right, left or both. Afterwards, the occlusal forces in habitual occlusion, using T-Scan III Electronic device (IP-CO position mode, MA-mode, MA sensitivity setting) were measured. The data were presented as Mean ± SD. Spearman correlation was used to find the correlation between the occlusal force and chewing side. Differences in P < 0.05 were considered significant. There were 90 subjects (46 female and 44 male) mean age 23.3 (SD ± 2.2 years) included in the study. The preferred chewing side of 42 subjects was the right side, 24 of them preferred the left side and the other 24 preferred both sides as the chewing side. Occlusal force was higher in the preferred chewing side (P < 0.05) but using Spearman correlation, there was no statistical significance of occlusal force between the groups, the left side (r = −0.143, P > 0.05) and the right side (r = 0.143, P > 0.05) according to the preferred chewing side. In this study, the relation between the preferred chewing side and occlusal force was found.

The maxillary second molar contains three roots and three canals. Variations of the maxillary second molar are reported in numerous studies in vitro and in vivo. Dentists are required to have adequate knowledge related to root canal morphology and their possible variations. The aim of this study was to present a case report about a diagnosis and treatment in maxillary second molar with single root and single canal. It is concluded that the diagnosing of these unusual cases is of high importance for successful endodontic treatment of these teeth.

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