Distúrbios respiratórios do sono e dimensões dos arcos dentários em crianças respiradoras orais antes e após adenotonsilectomia

Abstract

Introduction: Upper airway obstruction due to tonsil and adenoid hypertrophy can lead to changes in the craniofacial and dentoalveolar growth and development, being the most common cause of obstructive sleep apnea and snoring in children. Objectives: Evaluate the size of dental arches in mouth breathing children (MB) before and after AT and to compare them to nasal breathers (NB) paired by age and gender in T0. Additionally, evaluate the prevalence of sleep apnea, its severity by apnea and hypopnea index (AHI), snoring, and risk factors such as obesity and allergic rhinitis for SBD. Material and methods: Observational, prospective and cross-sectional study in mouth breathing children evaluated at the Outpatient Clinic for Mouth Breathing Children at Hospital das Clínicas of UFMG between September 2013 and September 2014. One hundred and twelve children were evaluated. Thirty-seven had severe lymphoid tissue hypertrophy (adenoid 75% and / or grade 3 or 4 tonsils). Twenty children (mean 5.5 years) met the inclusion and exclusion criteria, 15 were submitted to AT, composing the adenotonsillectomy group (ATG). The five children, who did not receive surgical intervention during 1-year observation period, composed the obstructed comparison group (OCG). All MB children were submitted to baseline clinical examination, polysomnography, allergic test, fibronasolaryngoscopy and orthodontic cast models at T0, and also after a mean of 1.7 years later (T1). Results: Out of the 20 children included in the sample, 65% had obstructive sleep apnea: 10 from the ATG (mean of the AHI = 2.4 ev/hour) and three from the OCG (mean IAH = 1.1 ev/hour). Snoring was diagnosed in 90% of the MB children at the polysomnography exam. Regarding nutritional status, body mass index (BMI / gender / age), 10% were overweight, 30% obese and 15% were underweight. Allergic rhinitis was diagnosed in 55% of children and septum deviation in 30%. Out of 10 apneic children from the ATG at T0, 7 children maintained obstructive sleep apnea and one presented apnea in T1 (mean AHI of 1.9 ev/hour). Out of the three apneic children from GCO, one maintained apnea in T1 (mean of 0.9 ev/hour). After surgery, the children gained an average of 9 Kg, presenting 40% of obesity. Low-weight children achieved adequate weight and those who were overweight became obese. There was a statistically significant difference in BMI and cervical circumference, demonstrating weight gain after AT. There was no statistically significant difference between the dental dimensions of MB and NB children at T0 (independent t-test). In the ATG group, after a mean follow-up of 1.4 years after AT, and in the OCG group, the measurements of the dental arches between T0 and T1 did not change significantly (paired t-test). Conclusion: There was no significant difference in the dimensions of the dental arches between oral and nasal breathers even after clearing the upper airway. Obstructive sleep apnea and snoring were diagnosed in most children. However, AT did not cause a significant reduction in AHI. Mouth breathers with indication of AT had an increased prevalence of risk factors for SBD.