[Frequency of rhinitis and orofacial disorders in patients with dental malocclusion]

To describe the frequency and etiology of rhinitis, oral breathing, types of malocclusion and orofacial disorders in patients treated for dental malocclusion.

Patients with poor dental occlusion (n=89, 8-15 years) undergoing orthodontic treatment at the Postgraduate Orthodontics Center (Sao Paulo, Brazil) participated in the study. Rhinitis and oral breathing were diagnosed by anamnesis, clinical assessment and allergic etiology of rhinitis through immediate hypersensitivity skin prick test (SPT) with airborne allergens. The association between types of breathing (oral or nasal), rhinitis and types of dental malocclusion, bruxism and cephalometric alterations (increased Y axis of facial growth) compared to standard cephalometric tracing (Escola de Odontologia da Universidade de São Paulo) were assessed.

The frequency of rhinitis in patients with dental malocclusion was 76.4% (68), and, of these, 81.7% were allergic (49/60 positive skin prick test), whereas the frequency of oral breathing was 62.9%. There was a significant association between an increased Y axis of facial growth and oral breathing (p<0.001), as well as between oral breathing and rhinitis (p=0.009). There was no association between rhinitis and bruxism.

The frequency of rhinitis in children with dental malocclusion is higher than that in the general population, which is approximately 30%. Patients with oral breathing have a tendency to a dolichofacial growth pattern (increased Y axis of facial growth). In patients with rhinitis, regardless of the presence of oral breathing, the dolichofacial growth tendency was not observed.