Anterior segmental osteomy versus orthodontic camouflage treatment decision: The importance of incisor mandibular plane angle

Objectives Temporary anchorage devices (TADs) have reduced the need for anterior segmental ostomy (ASO) in Class I patients; however, ASO remains relevant in Class II patients. As previous studies were conducted before the usage of TADs, updated guidelines are required to determine the relationship between surgery and orthodontic treatment. This study aimed to evaluate the hard tissue changes following ASO versus non-ASO (NASO) orthodontic treatment utilizing TADs with premolar extraction. Materials and Methods This retrospective clinical study involved 67 patients (18 male, 49 female; mean age: 33.9 years) diagnosed with skeletal Class II malocclusion. The patients were categorized into the ASO (n = 31) and NASO (n = 36) groups. Cephalometric analyses were conducted to compare initial and final records to assess the treatment effects Results Pre-and post-treatment changes in the ASO and NASO groups exhibited significant differences in ΔSNA, ΔSNB, ΔANB, ΔA to N-perp, ΔB to N-perp, ΔPog to N-perp, and ΔA to FH ( P  < 0.05). While the reduction in ANB in the ASO group compared with that in the NASO group was clinically significant at 1.77, both groups demonstrated normalized ANB, indicating significant skeletal improvement in Class II malocclusion. Specifically, the change in FMIA (ΔL1 to FH [°]) was 4.98° greater in the NASO group than in the ASO group ( P  < 0.05). Conclusions Our findings revealed the importance of the incisor mandibular plane angle (IMPA) in treatment decision-making between ASO and NASO treatment. Clinical Relevance: This study highlights IMPA's importance in treatment planning and aids in selecting ASO and NASO treatments.