The effect of two different extraction protocols in the treatment of Class II, Division 1 malocclusion on the angulation of developing mandibular third molars
Introduction: The extraction of premolars is a common therapeutic approach in the treatment of Class II, Division 1 malocclusion. Aim: This study aimed to test the null hypothesis that there is no statistically significant difference in the change in angulation of developing mandibular third molars between patients with Class II, Division 1 malocclusion treated with the extraction of maxillary first and mandibular second premolars and those treated with the extraction of maxillary second premolars. Materials and Methods: The study included orthopantomographic radiographs taken before and after orthodontic treatment in 28 patients aged 15-22 years with Class II, Division 1 malocclusion. The patients were divided into Group I (n = 14), treated with the extraction of maxillary second premolars only, and Group II (n = 14), treated with extraction of maxillary first and mandibular second premolars. Statistical analysis was performed using descriptive statistics and appropriate inferential tests (Student's t-test, Pearson's χ² test, and Mann-Whitney test), with the level of statistical significance set at p < 0.05. Results: The mean change in angulation of developing mandibular third molars in group II were positive and significantly different from that observed in Group I (p < 0.01). No statistically significant differences were found between the left and right sides within either group. The percentage of lower third molars showing an increase in angulation was 32.14% in Group I and 71.43% in Group II. Conclusion: The null hypothesis was rejected. Orthodontic treatment of Class II, Division 1 malocclusion involving the extraction of maxillary first and mandibular second premolars increase the likelihood of mandibular third molar eruption by producing a significantly greater change in their angulation.