Department of Orthodontics, University of Oslo, Norway.
Eur J Orthod. 2020 Sep 11;42(4):426-433. doi: 10.1093/ejo/cjz055.
High-angle skeletal Class II malocclusion is one of the most challenging dentofacial deviations to treat and, in adults, a combination of orthodontic treatment and bimaxillary orthognathic surgery is often indicated. This study examines the rate of clinically significant relapse and whether a genioplasty affects the treatment outcome of high-angle Class II malocclusions.
Cephalometric tracings of 36 consecutively treated high-angle Class II patients were evaluated from pre-surgery to 3 years post-surgery. All patients had undergone bimaxillary surgery (Le Fort I and BSSO), 13 of them had in addition a genioplasty.
The maxilla remained stable, whereas relapse (greater than or equal to 2 mm) of the mandibular advancement was seen in 40 per cent of the patients. Advancement greater than 10 mm increased the risk for horizontal relapse. The overjet was normalized and remained stable despite mandibular relapse. Half of the patients had an anterior open bite 3 years post-surgery. A supplemental genioplasty did not affect the relapse rate.
Overjet was normalized and remained stable long term; there was an open bite in half of the patients. Combined orthodontic and bimaxillary surgical treatment of high-angle Class II patients showed skeletal relapse (greater than or equal to 2 mm) of the mandible in 40 per cent of patients. Mandibular advancement greater than 10 mm increased the risk for relapse. There was no increased risk for dental or skeletal instability associated with a genioplasty in combination with maxillary and mandibular surgery in the treatment of high-angle skeletal Class II malocclusion.
高角型骨性 II 类错[牙合]是最具挑战性的牙颌面畸形之一，对于成人患者，常需要正畸治疗联合双颌正颌手术。本研究旨在探讨高角型骨性 II 类错[牙合]患者术后是否存在临床意义上的复发，以及颏成形术对高角型 II 类错[牙合]治疗结果的影响。
回顾性分析 36 例连续治疗的高角型骨性 II 类错[牙合]患者的头颅侧位片，术前至术后 3 年进行随访。所有患者均接受双颌手术（Le Fort I 截骨术+下颌骨矢状劈开截骨术），其中 13 例患者同期行颏成形术。
上颌骨保持稳定，而下颌骨的前移发生了 40%的复发（大于等于 2mm）。下颌骨前移大于 10mm 增加了水平复发的风险。尽管下颌骨发生了复发，但是覆[牙合]仍得到了纠正并保持稳定。术后 3 年，有一半的患者存在前牙开[牙合]。补充颏成形术并没有影响复发率。
覆[牙合]得到了纠正并长期保持稳定；术后有一半的患者存在前牙开[牙合]。正畸联合双颌正颌手术治疗高角型骨性 II 类错[牙合]患者，40%的患者出现了下颌骨的复发（大于等于 2mm）。下颌骨前移大于 10mm 增加了复发的风险。在治疗高角型骨性 II 类错[牙合]时，同期行颏成形术联合上颌骨和下颌骨手术并不会增加牙颌稳定性的风险。
