Abstract There are divergences among studies regarding features associated to increased risk of osteoradionecrosis (ORN). Our objective was to identify factors that predispose to the development of ORN of the jaw. This was a retrospective, hospital-based, case-control study involving patients with head and neck cancer who had been treated with ≥ 60 Gy external radiotherapy (RT) to the jaw. A total of 19 cases of ORN and 43 controls were included. The patients’ demographic data, tumor type, staging, treatment and outcome information, and pre-treatment oral status were collected. Univariate analysis showed that the oral cavity/oropharynx sites were associated with 9.77-fold increased risk of ORN development compared to other sites (p = 0.005). Being an active smoker was associated with 3.95-fold increased risk of ORN development (p = 0.01). A tendency towards increased risk of ORN was observed particularly when tooth extraction occurred after RT (odds ratio (OR): 3.04; p = 0.08). Multivariable analysis showed that tumor site was the only significant risk factor (OR: 21.03, p = 0.01). The oral and oropharyngeal primary site is an important risk factor for ORN. Dental extraction, which did not occur in 28% of the sample, was not an essential event for ORN development.

Resumo Objetivo: Descrever os fatores associados à cárie dentária em escolares de Santa Cruz do Sul, Rio Grande do Sul, Brasil. Métodos: Um estudo transversal foi feito em uma amostra aleatória de 623 estudantes de ambos os sexos, entre 10 e 17 anos. A cárie dentária foi avaliada com o índice da Organização Mundial de Saúde (1997) CPO-D (dentição permanente), que constitui a soma de dentes cariados, perdidos e obturados por pessoa. A escolaridade materna foi avaliada com os critérios da Associação Brasileira de Empresas de Pesquisa. As demais variáveis foram obtidas com um questionário estruturado. A análise de regressão de Poisson foi usada para testar a associação entre as variáveis, com modelos consistentes e um modelo ajustado posteriormente. Os dados foram expressos como razão de prevalência (RP). Resultados: A análise multivariada identificou os seguintes fatores relacionados à experiência de cárie dentária: residência em municípios rurais (RP: 1,15; IC95%: 1,0-1,3), frequentar uma escola municipal (RP: 3,30; IC95%: 1,1-9,4) ou estadual (RP: 3,40; IC95%: 1,1-9,6); e ter uma mãe analfabeta ou uma mãe que só estudou até a 4ª série do Ensino Fundamental (RP: 1,67; IC95%: 1,1-2,4) ou o ensino médio (RP: 1,54; IC95%: 1,1-2,2). Conclusões: A presença de cárie em alunos no sul do Brasil foi associada com residência em áreas rurais, mãe com baixo nível educacional e frequentar escola pública.

Abstract Objective: To describe the factors associated with dental caries among students from Santa Cruz do Sul, Rio Grande do Sul, Brazil. Methods: A cross-sectional study was conducted in a random sample of 623 students of both genders, aged 10-17 years old. Tooth decay was performed using the index of the World Health Organization (1997), DMFT (permanent dentition) that expresses the sum of decayed, missing and filled teeth per person. The maternal educational level was rated using criteria of the Brazilian Association of Market Research Companies. The remaining variables were obtained by a structured questionnaire. Poisson regression analysis was used to test the association between variables using robust models and a subsequently adjusted model. Data were expressed as prevalence ratio (PR). Results: Multivariate analysis identified the following factors related to the experience of dental caries: residence in rural municipalities (PR: 1.15; 95%CI: 1.0-1.3), attending a city school (PR: 3.30; 95%CI: 1.1-9.4) or a state school (PR: 3.40; 95%CI: 1.1-9.6); and having an illiterate mother or a mother that only attended up to the 4th year of school (PR: 1.67; 95%CI: 1.1-2.4) or high school (PR: 1.54; 95%CI: 1.1-2.2). Conclusions: The presence of caries in students in southern Brazil was associated with residence in rural areas, mother with little education and attendance to a public school.