Tooth size discrepancies and arch parameters among different malocclusions in a Jordanian sample

The objectives of this study were to determine the mean mesiodistal tooth width of the dentition, Bolton anterior and overall ratios, arch length, and arch width in the different malocclusions in a Jordanian sample. The mesiodistal tooth width, arch width, and length were measured on a total of 140 orthodontic models of school students aged 13-15 years of different occlusal relationships (Class I, Class II division 1, Class II division 2, and Class III malocclusions). Anterior and overall Bolton ratios were calculated. The mean and standard deviation were calculated. Student's t-test and analysis of variance were used for the statistical analysis. The results show that (1) females have smaller teeth than males; (2) Class III malocclusion showed larger teeth than the rest of the other occlusal categories; (3) no statistically significant differences were found in Bolton ratios between the different malocclusions; (4) Class II division 1 showed the narrowest maxillary arch compared with the other types of malocclusion; (5) the mandibular intercanine width was significantly larger in Class III group than in Class II division 1 and Class II division 2 groups; (6) the maxillary arch was significantly longer in Class II division 1 than in Class II division 2; and (7) the mandibular arch of both Class II categories was significantly shorter than Class III malocclusion group. In conclusion, tooth size differences were found between right and left sides, between females and males, and between the different malocclusions. Arch width and length also showed differences among the different malocclusions.