치아 및 악궁의 크기와 총생의 관계

Abstract

This investigation was undertaken to examine the extent to which tooth size and arch dimension each contribute to dental crowding. The samples included 50 subjects with gross dental crowding(25 males, 25 females) and those of 40 subjects with well aligned dentition(20 males, 20 females). Plaster models and digital models were made from alginate impression taken at the one visit. Tooth size, arch length, arch perimeter, intercanine width and intermolar width were measured on the plaster and digital models. The findings in this study lead to the following results. 1. In maxilla, the mesiodistal diameter of lateral incisors and premolars of the crowded group were significantly larger than those of the normal occlusion group(P<0.05). 2. In mandible, the mesiodistal diameters of central incisors, canines and premolars of crowded group were significantly larger than those of the normal occlusion group(P<0.05). 3. In maxilla, arch perimeters and intermolar widths of crowded group were significantly smaller than normal occlusion group but intercanine width of crowded group were larger than normal occlusion group(P<0.05). There was no significantly difference in arch length(P>0.05). 4. In mandible, Arch perimeters of crowded group was smaller than normal occlusion group(P<0.05). There were no difference in arch length, intermolar width and intercanine width(P>0.05). 5. In the analysis of correlation coefficients of ALD with variables, Arch perimeters, intermolar widths and mesiodistal widths of 2nd premolar showed positive correlations in maxilla. 6. There was a significant difference between tooth width measurements made by the 2 methods, with all the digital model measurements larger than plaster model measurements(P<0.05) : the magnitude of the differences does not appear to be clinically relevant 7. In the analysis for reproducibility, The plaster model measurement was showed lower degree of correlation between 1st and 2nd measurement than digital model.