Abstract The aim of the present study was to investigate predictors of malocclusion in Brazilian schoolchildren eight to ten years of age based on a causal directed acyclic graph model. A cross-sectional study was conducted with 739 schoolchildren eight to ten years of age. Parents/guardians provided information on sleep disorders of the child (Sleep Disturbance Scale for Children) and family characteristics (Family Adaptability and Cohesion Evaluation Scale). The diagnosis of malocclusion was performed by four trained examiners using the Dental Aesthetic Index. Control variables were selected using a directed acyclic graph. Descriptive analysis was performed, followed by robust logistic regression analysis for complex samples (α = 5%). The following variables were associated with malocclusion in the final model: sleep disorders (OR = 2.61; 95%CI: 2.43–2.86), mouth breathing (OR = 1.04; 95%CI: 1.02–1.99), non-nutritive sucking habits (OR = 2.45; 95%CI: 2.37–4.85), and obesity (OR = 1.54; 95%CI: 1.02–2.33). Sociodemographic characteristics, family functioning, and premature tooth loss did not remain associated with malocclusion. Sleep disorders, mouth breathing, sucking habits, and obesity are predictors of malocclusion in schoolchildren eight to ten years of age.

ABSTRACT Background Sleep bruxism (BS) is defined as involuntary jaw movements characterized by grinding and clenching teeth. Objective To verify the association between chronotype, sleep quality, and self-reporting of BS in dental students. Method A cross-sectional study was conducted with 214 undergraduate dental students at a public university in northeast Brazil. The participants answered the Munich Chronotype Questionnaire for the identification of chronotype and another questionnaire regarding daily aspects to collect information about sleep quality, self-reported sleep bruxism, the use of sleeping pills, snoring, concentration during daily activities and energy upon waking. Results The prevalence of self-reported sleep bruxism was 11.0%. In the final model, the eveningness chronotype (OR = 23.00; 95% CI: 2.36-223.84, p = 0.007), habitual snoring (OR = 3.12; 95% CI: 1.31-7.39, p = 0.01) and low energy upon waking in the morning (OR = 2.37; 95% CI: 1.96-5.58, p = 0.040) were associated with self-reported sleep bruxism. Conclusion The evening chronotype, presence of snoring, and low energy when waking up in the morning influenced self-reporting of sleep bruxism among undergraduate dental students.

RESUMO Introdução O bruxismo do sono (BS) é definido como movimentos involuntários da mandíbula caracterizados por ranger e apertar os dentes. Objetivo Verificar se o cronotipo e a qualidade do sono estão associados ao autorrelato de BS em graduandos de Odontologia. Método Um estudo transversal com 214 estudantes de uma universidade pública do Nordeste do Brasil. Os participantes responderam ao Morningness-Eveningness Questionnaire para identificar os cronotipos e outro questionário sobre aspectos diários em que foram coletadas informações sobre qualidade do sono, autorrelato de bruxismo do sono, uso de pílulas para dormir, ronco, concentração nas atividades diárias, energia ao acordar. Resultados A prevalência de autorrelato do bruxismo do sono foi de 11,0%. No modelo final, o cronotipo noturno (OR = 23,00; 95% IC: 2.36-223.84, p = 0,007), o hábito de roncar (OR = 3,12; 95% IC: 1.31-7.39, p = 0,01) e o baixo nível de energia ao acordar pela manhã (OR = 2,37; 95% IC: 1.96-5.58, p = 0,04) estiveram associados com o autorrelato de BS. Conclusão O cronotipo noturno, a presença do ronco e a baixa energia ao se levantar pela manhã influenciaram o autorrelato de bruxismo do sono entre os estudantes de graduação em Odontologia.

Resumo Objetivo Esta pesquisa investigou a presença de reabsorção radicular externa (RRE) em segundos molares ocasionada pelos terceiros molares impactados em radiografias panorâmicas, relacionando com a posição dos terceiros de acordo com a classificação de Winter e de Pell e Gregory. Material e método Um estudo transversal, retrospectivo, por meio de radiografias panorâmicas obtidas no período de janeiro de 2014 a dezembro de 2015. Adotou-se como critério de inclusão, a presença um segundo molar adjacente a um terceiro molar impactado. Os dados foram analisados por meio de estatística descritiva e inferencial. Foram realizados o Teste Qui-Quadrado de Pearson e Teste Exato de Fisher (p≤0,05). Resultado A amostra foi composta por 584 radiografias panorâmicas, sendo 356 (60,95%) do gênero feminino e 228 (39,05%) do masculino, a média de idade foi de 25,31 anos. A prevalência de RRE foi de 12,5%, e a faixa etária de 14-24 anos foi mais acometida (p=0,46). A presença de RRE foi estatisticamente maior na mandíbula (42,1%) com p=0,01. As RRE localizadas nos terços cervical (57,1%) e médio (58,8%) foram proporcionalmente maiores nos dentes nas posições B2 (p=0,02), e mesioangular (p=0,26). Conclusão A prevalência de RRE em segundos molares causada por terceiros impactados se mostrou estar de acordo com a média existente na literatura mundial, sem predileção por gênero, acometendo mais pacientes jovens, frequentemente ocorre nos dentes da mandíbula e apresenta um maior grau de severidade no terço cervical e médio. As posições B2 e mesioangular apresentaram maior propensão à RRE.

Abstract Objective This research investigate the presence of external root resorption (ERR) in second molars caused by impacted third molars in panoramic radiographs, relating to the position of third molars according to classification of Winter, Pell and Gregory. Material and method A cross-sectional, retrospective study using panoramic radiographs obtained from January 2014 to December 2015. The inclusion criterion was the presence of a second molar adjacent to an impacted third molar. Data were analyzed using descriptive and inferential statistics. Pearson's Chi-Square Test and Fisher's Exact Test (p≤0.05) were performed. Result The sample consisted of 584 panoramic radiographs, 356 (60.95%) of women, and 228 (39.05%) of men, the mean age was 25.31 years. The prevalence of ERR was 12.5%, and the group of 14-24 year olds was the most affected (p = 0.46). The presence of ERR was statistically higher in the mandible (42.1%) with p=0.01. The ERR located in the cervical (57.1%) and medium (58.8%) thirds was proportionally higher in the teeth with B2 (p=0.02) and mesio-angular positions (p=0.26). Conclusion The prevalence of ERR in second molars, caused by impacted third molars, was shown to be similar to results found in the literature, with no gender preference, this affects young patients, occurring frequently in mandible teeth, and presents greater severity in the cervical and middle thirds. The B2 and mesio-angular positions were more prone to ERR.