Study on the difference of curative effect between orthodontic priority mode and surgical priority modeon skeletal class Ⅲ patients
正畸优先模式与手术优先模式对骨性Ⅲ类患者疗效的差异性研究

摘要

安氏Ⅲ类错牙合畸形的患病率有较明显的种族差异。欧美国家患病率为0.8%～2.0%,亚洲国家为4%～20%。我国安氏Ⅲ类错牙合畸形的总患病率为4.76%（95%CI：3.85%～6.54%）。安氏Ⅲ类错牙合畸形常表现为单纯上颌后缩、单纯下颌前突，或两者兼有。安氏Ⅲ类错牙合的病例多伴有骨性Ⅲ类错牙合畸形，部分病例可以通过单纯正畸的方式进行掩饰性治疗。而对于严重的骨性Ⅲ类错牙合畸形的成年患者，通常采用正畸-正颌联合治疗，此类患者常已出现较明显的牙齿代偿现象。有学者认为如果Ⅲ类患者具备以下6种情况中的4种（覆盖≤-4.73 mm； Wits≤-11.18 mm； IMPA≤80.8°；Mx/Mn≤65.9%；覆牙合≤-0.18 mm；下颌角≥120.8°），那么患者将被建议手术治疗。传统的正颌手术时机取决于9～18个月术前正畸排齐整平、去代偿的程度，这个过程有助于产生一个可预测的精确结果。

Abstract

There are obvious racial differences in the prevalence of Angle Class Ⅲ malocclusion. The prevalence rate is 0.8% ~ 2.0% in Europe and America, and 4% ~ 20% in Asian countries. The total prevalence of Class Ⅲ malocclusion in China is 4.76% (95% CI: 3.85% ~ 6.54%). Angle class Ⅲ malocclusion often manifests as simple maxillary retraction, simple mandibular protrusion, or both. Most cases of Angle's Class Ⅲ malocclusion are accompanied by skeletal Class Ⅲ malocclusion, and some cases can be treated by simple orthodontics. For adult patients with severe skeletal class Ⅲ malocclusion, orthodontics-orthognathic treatment is usually used, and such patients often have obvious tooth compensation. Some scholars believe that if class Ⅲ patients have four of the following six conditions (coverage ≤-4.73 mm; Wits≤-11.18 mm; IMPA≤80.8°; Mx/Mn≤65.9%; Overbite ≤-0.18 mm; Mandibular angle ≥ 120.8), then the patient will be recommended for surgical treatment. The timing of traditional orthognathic surgery depends on the degree of orthodontic alignment and decompensation 9 ~ 18 months before operation, which is helpful to produce a predictable and accurate result.