Abstract Objective: Investigate the influence of posterior crossbite on masticatory and swallowing functions by videofluoroscopy examination and to analyze the effects of Rapid Maxillary Expansion (RME) on the same functions. Methods: A prospective longitudinal study was conducted on 32 children, 21 of them with posterior crossbite (10 girls and 11 boys, mean age 9.2 years, study group) and 11 children with no occlusal changes (6 girls and 5 boys, mean age 9.3 years, control group). The children were evaluated by an orthodontist for diagnosis, group characterization and occlusal treatment, by the otorhinolaryngology team for the assessment of respiratory symptoms, and by a speech therapist for videofluoroscopic evaluation of masticatory and swallowing parameters. The children with posterior crossbite were treated orthodontic ally using the Haas disjunctor for approximately six months and re-evaluated 5-months after removal of the appliance. Data were analyzed statistically by the Studentt-test for independent samples for comparison of the crossbite and control groups before and after treatment. Results: There was no significant difference in oral preparatory and oral transit times, nor in cycles and masticatory frequency, between the pre and post orthodontic treatment groups and the control group. Conclusion: Rapid maxillary expansion did not influence the masticatory and swallowing variables studied by videofluoroscopy. However, the data require caution in interpretation.

OBJETIVO: A amamentação promove vários benefícios na criança, entre eles o favorecimento da respiração nasal. Neste estudo verificou-se a relação do padrão respiratório com o histórico de aleitamento e hábitos orais deletérios. FORMA DE ESTUDO: clínico com coorte transversal. MATERIAL E MÉTODO: A população foi constituída por 62 crianças, de 3 anos e 3 meses a 6 anos e 11 meses, as quais foram submetidas à avaliação otorrinolaringológica, para definição dos grupos respiradores nasais e orais e entrevista fonoaudiológica. A avaliação otorrinolaringológica constituiu-se dos seguintes exames: rinoscopia anterior, oroscopia e exame radiológico. Os pais das crianças foram questionados em relação à forma (natural e/ou artificial), e ao período de aleitamento, além da presença de hábitos orais deletérios (sucção e mordida). O teste Exato de Fisher foi utilizado para comparar os grupos em relação à presença ou ausência de hábitos e diferentes períodos de aleitamento. RESULTADOS: O período de aleitamento materno foi maior nos respiradores nasais concentrando-se no período de 3 a 6 meses de idade. Quanto ao uso de mamadeira, os resultados mostraram que a maioria das crianças de ambos os grupos utilizou-se deste tipo de aleitamento nos primeiros anos de vida, não apresentando diferença estatística entre os grupos (p=0.58). A presença de hábitos orais deletérios ocorreu de maneira marcante nos respiradores orais, evidenciando diferença estatisticamente significativa, entre os grupos, para os hábitos de sucção (p=0.004) e hábitos de mordida (p=0.0002). CONCLUSÃO: As crianças respiradoras orais apresentaram um menor período de aleitamento materno e um histórico de hábitos orais presentes comparadas às crianças respiradoras nasais.

AIM: Breast-feeding promotes several benefits in childhood, among them favoring the nasal breathing. In the present study, the relationship between breathing pattern and the history of breast-feeding and of deleterious oral habits was determined. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: The study population consisted of 62 children ranging in age from 3 years and 3 months to 6 years and 11 months who were submitted to otorhinolaryngologic evaluation to determine nasal and mouth breathers and to a speech language pathologic interview. The otorhinolaryngologic evaluation involved the following exams: anterior rhinoscopy, oroscopy and radiologic examination. The parents of the children were questioned about the form of feeding (natural and/or artificial), the duration of breast-feeding and the presence of deleterious oral habits (suction and biting). The Fisher exact test was used to compare groups regarding the presence and absence of habits and the different periods of breast-feeding. RESULTS: The breast-feeding period was longer among nasal breathers and was concentrated in the period between 3 and 6 months of age. Regarding the use of bottle, the results showed that most of the children in both groups used this type of feeding during the first years of life, with no significant difference between groups (p=0.58). There was a marked presence of deleterious oral habits among mouth breathers, with a statistically significant difference between groups regarding suction (p=0.004) and biting habits (p=0.0002). CONCLUSION: Mouth breathing children were breast-fed for a shorter period of time and had a history of deleterious oral habits compared to nose breathers.