Background:To investigate the proper modifications and usefulness of side-hairline correction surgery in Korean female patients depending on different zygomatic bone structures.Methods:Different zygomatic bone structures were classified according to their maximum transverse width among 310 cases of hairline correction surgery in Korean women. The widest transverse width was located on the anterior zygomatic malar area in type 1, on the mid-zygomatic arch in type 2, and on the posterior zygomatic arch in type 3; there was no difference in the transverse width between the anterior and posterior zygomatic arch in type 4. Various modifications of side-hairline correction surgery were performed among the 310 cases according to the zygomatic bone classification.Results:Among 310 patients, 74 had a type 1 zygomatic structure, 106 had type 2, 46 had type 3, and 50 had type 4. Thirty-four patients exhibited different left and right transverse widths: type 1 + 2 (n = 26), type 2 + 3 (n = 6), type 1 + 3 (n = 1), and type 3 + 4 (n = 1). Satisfactory results were obtained in all patients without noticeable side effects. A minor touch-up procedure was performed in 14 patients to achieve density reinforcement 10 months postoperatively, and all 14 patients expressed satisfaction with the results.Conclusions:In East Asian patients, both side-hairline correction surgery and zygoma reduction can be considered eligible treatment options for the purpose of midface slimming. Especially in patients with a type 3 zygomatic bone structure, side-hairline correction surgery may be more effective than zygoma reduction surgery for midface slimming.