Determinants of anterior tooth loss in Chilean adults: data from the Chilean National Health Survey 2016-2017.

Objective: To describe prevalence of anterior tooth loss and its determinants among Chilean people aged over 15 years. Methods: Crosssectional study, using the sampling frame of the Chilean National Health Survey 2016-2017 (n=5473 participants). Multivariate logistic regressions were performed to obtain the prevalence and odds ratio (OR) for anterior tooth loss using a complex sampling method. We described anterior tooth loss affecting each jaw according to sex, age, educational level, urban/rural residence and having health insurance. Results: The odds of anterior tooth loss were 7.11 (95%CI: 4.57 - 10.78) and 4.84 (95%CI: 3.02 - 7.72) times higher for low-educated subjects compared to those with more educational, for the upper and lower jaw respectively. Also, the odds of anterior tooth loss for the upper jaw was 1.34 (CI 95%: 1.07 - 1.66) times higher in women, whereas for the lower jaw, no significant differences by sex were found (p-value 0.14). Adults having only the National Health Fund B insurance (FONASA B) had odds of losing one or more anterior teeth 2.43 (CI 95%: 1.34 - 4.39) times higher in the upper jaw and 2.08 (CI 95%: 1.03 - 4.20) in the lower jaw compared with those having Health Insurance Institutions (ISAPREs). Conclusion: Our study showed for the first time that anterior tooth loss is a widespread condition in Chile, with marked inequities by sex, age, educational level, and geographical area. People in the public health insurance system have a higher odds of anterior tooth loss.