Cross-Sectional Observational Study of the Differences in Cephalometric Parameters in German Class I/II Orthodontic...

Objectives: The correct classification of orthodontic patients is essential in individualized diagnostics and treatment planning. However, due to the complexity of the craniofacial skeleton and differences related to gender, age, and ethnicity, cephalometric analysis can be prone to errors. This multicenter, cross-sectional study aimed to compare cephalometric measurements between skeletal class I and II in German orthodontic patients and analyze the effect of gender/age subgroups. Materials and Methods: In total, 556 German orthodontic patients were included and stratified into skeletal class I (n = 210) and II (n = 346), based on the individualized ANB of Panagiotidis and Witt (Calculated_ANB). Both classes presented a mean age of 13 with a range of 6.6-41 years and 5.4-53 years in classes I and II, respectively. Regarding the gender variations, most participants were females, n = 194 (56%) among class I, and n = 125 (60%) among class II. Cephalometric parameters were compared between classes and among age and gender-specific subgroups, followed by identifying correlations and performing principal component analysis (PCA). Results: Class II patients presented a more considerable sagittal discrepancy between jaw bases than class I cases (Calculated_ANB 2.8° vs. 0.025°), a more horizontal growth pattern (Gonion angle 119° vs. 123°), and compensated inclinations of the incisors in the upper (+ 1/NL 71° vs. 68°) and lower jaw (-1/ML 84° vs. 80°). Correlations were found between sagittal, vertical, and dental cephalometric parameters, which were strongest in adult class II males. Finally, ML-NSL angle, SNPg angle, PFH/AFH ratio, and SNB angle are related to the variations of the first four components. Conclusions: The differences in cephalometric parameters between skeletal class I and II demonstrate certain configurations in vertical, sagittal, and dental parameters, and identifying these marks precisely will enable accurate diagnosis. In addition, the variations concerning gender and age highlight the possible influence of these factors on orthodontic diagnostics and treatment planning. Future studies with equal sample sizes among subgroups must validate these findings. Finally, the PCA results highlighted that the mandible's vertical and sagittal position has a strong influence on the diagnosis of skeletal class I/II, which highlights the importance of identifying the corresponding reference marks.