Purpose: Overtime work is associated with a risk of developing various diseases, including oral diseases. Oral Health-Related Quality of Life (OHRQoL) is a more comprehensive assessment than those of individual diseases and can be affected by longer working hours.

Methods: This cross-sectional study examined the association of overtime work duration with OHRQoL. Data were obtained from an online survey of Japanese workers in February 2016. OHRQoL was assessed using the Oral Health Impact Profile-49 (OHIP-49). Poisson regression with robust variance was used to estimate the ratio of means and 95% confidence intervals (CI) of overtime work duration for OHIP-49 scores after adjusting for sociodemographic and health behavior covariates.

Results: Of 2,764 (2,178 male and 586 female) workers (mean age, 44.6 ± 10.0 years), those with longer duration of overtime work tended to exhibit poorer OHRQoL. The mean OHIP-49 scores of those who did not work overtime and worked for ≥5 h overtime were 27.93 ± 28.53 and 40.97 ± 38.86, respectively. After adjusting for covariates, compared to those who did not work overtime, the mean OHIP-49 score was 1.41 times higher (95% CI 1.38-1.44) for those who worked for ≥5 h overtime.

Conclusion: Longer overtime work duration was associated with poor OHRQoL.