Association between upper airway obstruction and malocclusion in mouth-breathing children.

Objectives: To evaluate the association between upper airway obstruction and occlusal anomalies in mouth-breathing children.

Methods: 356 mouth-breathing children were evaluated by ENT physicians and specialists in orthodontics. ENT examination included nasal endoscopy to assess the adenoidal hypertrophy, tonsillar grading and presence of nasal septum deviation. Clinical orthodontic examination was performed to record occlusal variables. Univariate and multivariable logistic regression were performed to study the association between registered variables.

Results: 221 patients (mean age ± sd = 6.2 ± 2.5 years) met inclusion criteria. 81.4% of children presented malocclusion. A significant association between tonsillar grade 2 and the presence of malocclusion, Class II relation and increased overjet was shown. Tonsillar grade 4 showed a significant association with the presence of malocclusion and increased overjet. Adenoidal hypertrophy and nasal septum deviation did not show any association with occlusal findings.

Conclusions: A high frequency of orthodontic problems was seen in mouth-breathing children. Our results suggested that severe tonsillar hypertrophy may determine presence of malocclusion and increased overjet. On the other hand, the association between mild tonsillar hypertrophy and many occlusal anomalies in mouth-breathers suggest an important role of malocclusion in the onset of oral breathing in children.