December 2021

Objective: To test periodontal status as a mediator between socioeconomic status (SES) and oral health-related quality of life (OHRQoL) in pregnant women. Basic research design: Secondary cross-sectional analysis of baseline data from a randomised clinical trial with 303 pregnant women. Main outcome measures: Demographic variables, SES, smoking, interproximal hygiene, and self-reported gingival bleeding were collected as independent variables. The Oral Health Impact Profile-14 was used to assess OHRQoL. The relationship between SES, periodontal status and OHRQoL was investigated in structural equation modelling. Results: There was a moderate association of SES with periodontal status (standardised coefficient SC = -0.26, p<0.01) and number of teeth (SC = 0.24, p<0.01). Periodontal status and the number of teeth were also associated with OHRQoL (respectively, SC = 0.25, p<0.01 and SC = -0.31, p<0.01), but SES was only indirectly related to OHRQoL (SC = -0.17, p<0.01). Socioeconomic inequalities in quality of life were mainly explained by the remaining number of teeth, contributing to about 47%, and periodontal status, contributing to about 41%. Conclusions: There was no direct effect of SES on OHRQoL in pregnant women. Periodontal status and missing teeth each explained almost half of the total indirect association. Keywords: Quality of life, periodontal diseases, oral health, socioeconomic status