Abstract
Most studies dealing with the connection between dentition/occlusion and mouth breathing in children were done on hospital-based patients. The purpose of this study was to make a dentitional analysis of primary school children utilizing the raising of children with normal occlusion project conducted in Yamanashi Prefecture in 2002〜2003.
The following results were obtained :
1. The incidence of breathing through the mouth was 29.0% in all children, and that of the lip incompetence was 50.5%.
2. The incidence of abnormal swallowing was 29.9% in all children, and that of the tongue thrust habit was 18.9%. Each of which incidence decreased with age.
3. The mean of lip force increased with age. The mean of lip force of children with incompetent lips was significantly smaller than that of children who constantly closed their lips.
4. Otorhinolaryngological evaluation revealed that the most prevalent conditions present in children were rhinitis, which was found in 18.5% of subjects, and allergic rhinitis, 10.0%.
5. The appearance of maxillary protrusion comparing normal occlusion correlated to the "mouth breathing,""abnormal swallowing,""rhinitis,"of the dental and otorhinolaryngological evaluation ; and "lip biting,""bruxism,""runny nose,""mouth breathing,""swimming school"of the questionnaire survey.
6. The"mouth breathing"of the dental evaluation correlated to the factor of "oral habits",while that of the questionnaire survey correlated to the factor of "nasal airway".
