Impact of tooth loss related to number and position on oral health quality of life among adults

BACKGROUND: The objective of this study was to evaluate the impact of tooth loss on oral health-related quality of life (OHRQoL) in adults with emphasis on the number of teeth lost and their relative position in the mouth. METHODS: The study population was a cross-sectional household probability sample of 248, representing 149,635 20–64 year-old residents in Piracicaba-SP, Brazil. OHRQoL was measured using the OHIP-14. Socioeconomic, demographic, health literacy, dental services use data and clinical variables were collected. Oral examinations were performed using WHO criteria for caries diagnosis, using the DMFT index; that is, the sum of decayed, missing and filled teeth (DMFT). An ordinal scale for tooth loss, based on position and number of missing teeth, was the main explanatory variable. The total OHIP score was the outcome for negative binomial regression and OHIP prevalence was the outcome for logistic regression at 5% level. A hierarchical modeling approach was adopted according to conceptual model. RESULTS: OHIP score was 10.21 (SE 1.16) with 48.1% (n=115) reporting one or more impacts fairly/very often (OHIP prevalence). Significant prevalence rate ratios (PRRs) for OHIP severity were observed for those who had lost up to 12 teeth, including one or more anterior teeth (PRR=1.63, 95%CI 1.06–2.51), those who had lost 13–31 teeth (PRR=2.33, 95%CI 1.49–3.63), and the edentulous (PRR=2.66, 95%CI 1.55–4.57) compared with fully dentate adults. Other significant indicators included those who only sought dental care because of dental pain (PRR=1.67, 95%CI 1.11–2.51) or dental needs (PRR=1.84, 95%CI 1.24–2.71) and having untreated caries (PRR=1.57 95%CI 1.09–2.26). Tooth loss was not significantly associated with OHIP prevalence; instead using dental services due to dental pain (PR=2.43, 95%CI 1.01–5.82), having untreated caries (PR=3.96, 95%CI 1.85–8.51) and low income (PR=2.80, 95%CI 1.26–6.42) were significant risk indicators for reporting OHIP prevalence. CONCLUSION: Our analyses showed OHRQoL gradients consistent with the number and position of teeth missing due to oral disease. These findings suggest that the quantity of teeth lost does not necessarily reflect the impact of tooth mortality on OHRQoL and that future studies should take this into consideration.