Association between tooth loss and depression mediated by lifestyle and Inflammation- a cross-sectional investigation

Depression and tooth loss are associated with the occurrence of systemic disease or the progression of multi-factorial disease, and both are considered important public health issues by World Health Organization (WHO). Previous research just suggested that tooth loss can generate psychological stress, low self-esteem, anxiety and other emotional disturbances. However, the precise correlation and underlying mechanisms between depression and tooth loss remains poorly understood. ​Consequently, we aim to explore the association between depression and tooth loss through a cross-sectional study, as well as investigate potential pathways of influence.

We analyzed data from the National Health and Nutrition Examination Survey (NHANES). Logistic regression models were employed to examine the relationship between depression and tooth loss, as well as the associations among healthy lifestyle, systemic immune-inflammation index (SII), depression and tooth loss. Through the mediating effect analysis by bootstrapping analysis, we evaluated the mediating effects of healthy lifestyle and SII between depression and tooth loss.

Depressed patients were more likely to be toothless, and at the same time showed a tendency to have more missing teeth, with odds ratio (OR) = 1.305 (1.098, 1.551), p = 0.003 for 1-7 missing teeth, OR = 1.557 (1.166, 2.079), p = 0.003 for 8-14 missing teeth, and OR = 1.960 (1.476, 2.603), p<0.001 for 15-28 missing teeth. Lower healthy lifestyle scores and higher SII were both associated with more tooth loss. Healthy lifestyle and SII played a partial mediating role in this relationship, with a mediating effect ratio of 41.691% and 3.289%, respectively.

​Depression was positively associated with more severe tooth loss, which was partly mediated by lifestyle and SII. Therefore, attention should also be paid to the effects of depression as a mental disorder on physical health, such as depression and tooth loss. Adopting a healthier lifestyle and controlling systemic inflammation may be potential ways to reduce the impact of depression and tooth loss.