Background <p>To determine the apical root resorption (ARR) associated with three different orthodontic treatment methods for Class II malocclusion.</p> Methods <p>ARR of the upper and lower incisors was evaluated in patients treated with Forsus (FG; <i>n</i> = 20), headgear (CHG; <i>n</i> = 20), and fixed orthodontic appliances involving extraction of the upper first premolars (EG; <i>n</i> = 20). A total of 480 teeth were evaluated using panoramic radiographs obtained at T1 (after active treatment) and T2 (during retention). ARR was assessed using a scoring system ranging from 0 to 4. ANOVA, the Kruskal–Wallis test, and the chi-square test were used for statistical analysis.</p> Results <p>ARR of the lower right lateral incisors in the FG was greater than that in the CHG at T1 (<i>P</i> = 0.031). In the EG, greater ARR was observed in the upper right lateral incisors at T1 <i>(P</i> = 0.037) and in the upper left central incisors at T2 (<i>P</i> = 0.038) compared with the FG. The resorption scores of the incisors did not change between T1 and T2 in any group, except for the lower left central incisors.</p> Conclusions <p>Correction of Class II malocclusions using Forsus, headgear, or extraction of the maxillary first premolars followed by fixed appliance treatment results in varying degrees of ARR after active treatment.</p> Trial registration <p>Retrospective observational study. This study evaluated data from the years 2015 to 2024.</p>