Curve of Spee and Second Mandibular Premolar Agenesis—Present Knowledge and Future Perspectives

Background: We investigated the relationship between mandibular Curve of Spee (COS) and a persisting primary second molar (ppM2) due to an agenesis premolar, using digital software technique. Methods: Digital dental casts were obtained from 200 patients at Department Orthodontics in Innsbruck Vienna, Austria. Patients (age-, gender-, malocclusion-matched) equally divided into two groups (n = 100) according existence ppM2. COS depth, overjet, overbite, angle-classification measured digitally OnyxCeph3TM (version 3.2.147) software. ANOVA Kruskal–Wallis tests used analyze relationships. For statistical analyses, p < 0.05 was considered as statistically significant, 0.01 highly significant. Results visualized with box plots bar charts. Results: The deepest present Furthermore, positive correlation shown depth angle-class II, age, well overbite. No gender differences could be observed. Conclusions: In our study population dependent on whether there is ppM2 premolar or not, malocclusion sagittal direction.