Evaluation of arch morphology and intermaxillary tooth size ratios in patients with different sagittal and vertical direction anomalies

Objective: The aim of this study is to investigate the intermaxillary tooth size ratios and arch morphology in individuals with different sagittal and vertical direction anomalies who have completed their growth and development using 3D study models. Method: In this study, 3D study models of 103 skeletal Class I, 102 skeletal Class II, 91 skeletal Class III, 92 hyperdivergent, 104 hypodivergent, 100 normodivergent individuals were used. The plaster models of the individuals were scanned with a model scanning device (3Shape R700 Copenhagen, Denmark) and the groups were compared between classes after the measurements were made on the arch with the Orthoanalyzer program. In variables that did not show normal distribution, Kruskal- Wallis H test was used when there were more than two independent group comparisons, and One-way ANOVA test was applied for variables that showed normal distribution. Results: The Bolton overall ratio was found to be higher in Class III hypodivergent individuals than in normodivergent individuals (p=0,013), and in the hypodivergent Class III group compared to Class II and Class I individuals (p<0,05). The anterior ratio was found to be higher in Class III individuals than in Class I individuals (p=0,005). Interpremolar distance was found to be higher in normodivergent Class III individuals than in Class II individuals (p=0,009). Intermolar distance was found to be higher in Class III individuals than in Class II individuals in different vertical direction groups (p=0,001). Maxillary molar and canine depth were found to be higher in hyperdivergent Class II individuals than in Class III individuals (p=0,001, p=0,016, respectively). Arch perimetry showed significant differences according to the vertical direction in Class III patients (p=0,04). Palatal height was found to be higher in normodivergent Class III patients than in Class II individuals (p=0,04). The square arch shape was seen more frequently in Class II patients than in Class III patients. Conclusion: It was found that sagittal and vertical direction anomalies had no significant effect on arch morphology and Bolton values. Key words: Skeletal malocclusion, digital models, Bolton Analysis