Hard palate dimensions in nasal and mouth breathers from different etiologies.

PURPOSE To compare the hard palate dimensions of nasal-breathing children, mouth breathers from obstructive etiology, and habitual mouth breathers. METHODS The sample comprised 76 children, 37 boys and 39 girls, with mean age of 9.32±1.16 years, distributed according to the diagnosis of breathing mode and to the etiology of mouth breathing. Plaster cast models of the subjects' superior dental arch were obtained in order to measure the hard palate with a digital caliper. Measurements of transverse, vertical and anteroposterior palatal length were taken. The hard palate measures were compared among the groups through statistical analysis. RESULTS The comparison of hard palate dimensions observed in nasal and mouth breathers showed differences regarding the distance and depth of second premolars, and the distance of first molars. Differences were also found between the groups of mouth breathers regarding the hard palate depth at the level of canines. CONCLUSION Mouth breathers showed narrower hard palate at the level of second premolars and first molars, and deeper palate in the level of second premolars, when compared to nasal breathers. It is evidenced that habitual mouth breathers presented deeper hard palate at the level of canines, when compared to mouth breathers from obstructive etiology.