Wendl B, Muchitsch A P, Winsauer H, Walter A, Droschl H, Jakse N, Wendl M, Wendl T
Clinical Department of Oral Surgery and Orthodontics, Medical University Graz, Billrothgasse 4, 8036, Graz, Austria.
Private Practice, Bregenz, Austria.
J Orofac Orthop. 2017 May;78(3):201-210. doi: 10.1007/s00056-016-0076-7.
To assess early versus late treatment of Class III syndrome for skeletal and dental differences.
Thirty-eight Class III patients treated with a chincup were retrospectively analyzed. Baseline data were obtained by reviewing pretreatment (T0) anamnestic records, cephalograms, and casts. The cases were assigned to an early or a late treatment group based on age at T0 (up to 9 years or older than 9 years but before the pubertal growth spurt). Both groups were further compared based on posttreatment data (T1) and long-term follow-up data collected approximately 25 years after treatment (T2).
Early treatment was successful in 74% and late treatment in 67% of cases. More failures were noted among male patients. The late treatment group was characterized post therapeutically by significantly more pronounced skeletal parameters of jaw size relative to normal Class I values; in addition, a greater skeletal discrepancy between maxilla and mandible, higher values for mandibular length, Cond-Pog, ramus height, overjet, anterior posterior dysplasia indicator (APDI), lower anterior face height, and gonial angle were measured at T1. The angle between the AB line and mandibular plane was found to be larger at T0, T1, and T2, as well as more pronounced camouflage positions of the lower anterior teeth at T0. The early treatment group was found to exhibit greater amounts of negative overjet at T0 but more effective correction at T1.
Early treatment of Class III syndrome resulted in greater skeletal changes with less dental compensation.
评估Ⅲ类综合征早期治疗与晚期治疗在骨骼和牙齿差异方面的情况。
对38例使用颏兜治疗的Ⅲ类患者进行回顾性分析。通过回顾治疗前（T0）的问诊记录、头颅侧位片和模型获得基线数据。根据T0时的年龄（9岁及以下或9岁以上但青春期生长突增前）将病例分为早期治疗组或晚期治疗组。两组进一步根据治疗后数据（T1）以及治疗后约25年收集的长期随访数据（T2）进行比较。
74%的早期治疗病例成功，67%的晚期治疗病例成功。男性患者中失败病例更多。晚期治疗组治疗后相对于正常Ⅰ类值，颌骨大小的骨骼参数明显更显著；此外，在T1时测量到上颌骨与下颌骨之间更大的骨骼差异、下颌长度、髁突-颏点距离、升支高度、覆盖、前后发育异常指标（APDI）、较低的前面部高度和下颌角值。发现在T0、T1和T2时AB线与下颌平面之间的角度更大，以及在T0时下前牙更明显的掩饰性位置。早期治疗组在T0时表现出更大的负覆盖，但在T1时矫正更有效。
Ⅲ类综合征的早期治疗导致更大的骨骼变化且牙齿代偿较少。
