Relationship between handedness and toothbrush-related cervical dental abrasion in left- and right-handed individuals

Background/purpose: Cervical tooth abrasion is the loss of tooth material at the cementoenamel junction, and is usually related to faulty brushing habits. In this study, we attempted to evaluate the effects of handedness on tooth-brushing abrasion in terms of brushing habits in left- and right-handed adults. Materials and methods: In total, 488 subjects participating in the study were divided into 2 groups according to hand preference (group I; left-handed and group II; right-handed), and were interviewed about their brushing habits, and their clinical oral conditions such as the plaque index (PI), gingival index (GI), and tooth wear index (TWI) were determined. Handedness was determined by a questionnaire that focused on handedness using the Turkish version of the Edinburgh Handedness Inventory. Results: This study showed that there were no statistically significant differences between groups I and II according to daily tooth-brushing habits, PI, or GI. Statistically significant differences were found between men and women according to the clinical oral scores and brushing habits (P<0.01). However, there were no statistically significant differences between the mean TWI scores of left- and right-handed groups (P = 0.12). It was found that an increased frequency and longer duration of tooth-brushing significantly increased the TWI scores in both groups (P<0.01). It was also found that TWI scores were statistically higher in subjects who brushed horizontally rather than vertically (P<0.01). Correlations between clinical oral scores (TWI, PI, and GI) and brushing habits were statistically significant (P<0.01). Conclusion: The oral-hygiene performance of females was better than males. Brushing habits of patients were related to the severity of cervical wear. But no statistically significant relationship was found between hand preference and tooth-brushing abrasion in this study. Copyright (C) 2010, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.