Abstract
OBJECTIVE: To study the effects of mouth-breathing on maxillary arch development by comparing the palatal morphology of mouth- and nose-breathing children in mixed dentition. METHODS: Children in mixed dentition were enrolled and categorized into mouth-breathing (test group) and nose-breathing groups (control group) according to their breathing patterns. Children's plaster models were scanned with 3D laser scanner, and the 3D data were reconstructed and measured using Minics 15.0 and Geomagic 12.0 software. Measurement data (inter-molar width, palatal height, palatal volume, and palatal surface area) of the two groups were compared, and the correlation among the four measurement items was analyzed. RESULTS: The participants were 73 children (37 in test group and 36 in control group) with a mean age of (8.63±0.78) years old. The test group had significantly smaller inter-molar width, palatal volume, and palatal surface area but significantly higher palatal height than the control group (P<0.05). Inter-molar width and palatal volume were positively correlated with the palatal surface area in the test group (P<0.05). Inter-molar width and palatal height were positively correlated with the palatal surface area in the control group (P<0.01). CONCLUSIONS: Mouth-breathing children have significantly reduced inter-molar width, palatal volume, and surface, and substantially increased palatal height, leading to different developmental patterns of the palatal morphology.