Pasha S, et al. - Seventy-six individuals with right thoracic adolescent idiopathic scoliosis (AIS) with a 2-year follow-up were retrospectively incorporated in order to ascertain the difference in surgical decision making and the risk of suboptimal outcomes in each subtype according to the formerly developed 3D classification for right thoracic AIS patients. Among the five groups, the fusion length and the rate of radiographic suboptimal outcomes were statistically distinctive. Lower instrumented vertebrae (LIV) at T12 in Type 1 and upper instrumented vertebrae (UIV) at T2 in Type 2 had correlations with enhanced frontal balance (FB) and lower proximal junctional kyphosis (PJK), respectively. The greatest rate of suboptimal FB and developing PJK was noted in type 3. Type 4 had the most prolonged fusion, and suboptimal FB was seen in 42% of the patients independent from the LIV level. At 2 years, type 5 had the least rate of unsatisfactory radiographic outcomes. In conclusion, after the preoperative 3D classification of the AIS patients, it was exhibited that in each of the five subtypes, the UIV and LIV selection has a distinct influence on the surgical outcomes. Moreover, the suggested 3D classification has the potential for risk delamination after a posterior spinal surgery in the right thoracic AIS.