Evaluation of the Depth of the Curve of Spee, Overjet, and Overbite in Class I, Class II, and Class III Malocclusion among Patients at University of North Sumatera Dental Hospital

摘要

The curve of Spee is an important characteristic in the mandibular arch. An optimal occlusion must have a curve of Spee ranging from flat to mild. Therefore, an understanding of the curve of Spee is essential for both diagnosis and treatment planning in orthodontics. The aim of this study was to examine the difference in both the form and depth of the curve of Spee among class I, II, and III malocclusions and investigate the relationship between the depth of the curve of Spee with both overjet and overbite among patients at the University of North Sumatera Dental Hospital. A total of 100 dental study models with ages older than 15 years were enrolled and divided into 5 malocclusion groups: class I (n = 40), class II division 1 (n = 32), class II division 2 (n = 10), class II subdivision (n = 7), and class III (n = 11). The depth of the curve of Spee, overjet, and overbite was measured on dental study models with a digital caliper. The depth of curve of Spee was taken as the mean measurement from both sides of the arch on dental study models. The correlation coefficient between the depth of the curve of Spee and other variables were also calculated. The results showed that a maximum mean depth of the curve of Spee of 4.65 ± 1.41 mm in the class II division 2 group and a minimum depth of 2.34 ± 0.96 mm in the class III group. A statistically significant correlation was also found between the depth of the curve of Spee with both overbite and overjet. In conclusion, the curve of Spee was found to be deepest in class II division 2 followed by class II division 1, class II subdivision, class I, and class III malocclusion.