Objective: To assess the depth of the curve of Spee in Class I, class II division 1, Class II division 2 and class III malocclusions.
Materials and methods: Casts of 120 patients were selected and divided into 4 equal groups of 30 cases each. The casts were divided according to the malocclusion into Class I, Class II division 1, Class II division 2 and Class III malocclusions as defined by the British standards of classification. The depth of the curve of Spee was measured on each model after digitizing it using 3Shape Ortho analyzer 2019 software. Statistical analysis was performed for the collected data .
Results: results showed that class II division 2 cases had the deepest curve of Spee followed by Class II division 1 then Class I cases, while class III malocclusion showed the least depth of the curve of Spee. All groups showed a statistically significant difference in between except for Class I and Class III groups where no significant difference was found in between.
Conclusion: the depth of the curve of Spee is affected by the type of malocclusion