LAUSR

BACKGROUND AND AIM We investigated whether oral-dental conditions may be associated with the prevalence of irritable bowel syndrome (IBS) in a cross-sectional study in Japan. METHODS Information on lifestyle and abdominal symptoms was collected, and oral-dental examinations were performed from 2013 to 2017. To investigate the association between oral-dental conditions and IBS, this study used logistic regression analyses adjusted for relevant confounding factors, such as age, sex, BMI, stress, and eating between meals. RESULTS The prevalence of IBS was 484 (13.4%) among 3626 participants. The mean maximum occlusal force in the IBS group was significantly lower than that in the non-IBS group (0.306±0.192 kN vs. 0.329±0.205 kN, p =0.014). The maximum occlusal force of the constipation-type IBS was significantly lower than that of other types of IBS without constipation type (0.269±0.164 kN vs. 0.317±0.198 kN, p =0.010). Compared with those who had high values of maximum occlusal force (≧0.265 kN), those with a low value of maximum occlusal force (<0.265 kN) had a significantly greater risk for IBS (OR, 1.426; 95%CI, 1.135-1.792; p=0.002), by multivariate analyses, across different categories of oral-dental condition in women, not in men. Women who had lowest third occlusal force (<0.206 kN) had approximately 35% significanlty greater odds of having IBS compared with those who had highest third occlusal force (≧0.386 kN). CONCLUSIONS Results suggest that a reduction in the maximum occlusal force increases the risk of IBS in Japanese women.