Effects of the cervical headgear in growing Angle Class II malocclusion patients: a prospective study

ABSTRACT Objective: Evaluate dental and skeletal changes resulting from the exclusive use of the cervical headgear for 15 ± 4 months in the treatment of patients with Class II division 1 malocclusion. Methods: Differences between the beginning (T1) and immediately after the end of the therapy (T2) with the cervical headgear in growing patients (Experimental Group, EG, n = 23) were examined and compared, during compatible periods, with those presented by a group of untreated individuals (Control Group, CG, n =22) with similar malocclusions and chronological age. The cephalometric variables evaluated were: ANB, GoGn.SN, AO-BO, S'-ANS, S'-A, S'-B, S'-Pog and S'-U6 (maxillary first molar). The Shapiro-Wilk and Levene tests were used to evaluate the results. Results: Significant differences were found relative to the ANB, S'-U6, AO-BO, S'-ANS, S'-A, S'-B and S'-Pog variables between T1 and T2 when comparing both groups. No statistically significant variation was found regarding the GoGn.SN angle. Conclusions: The use of cervical headgear promoted distal movement of the maxillary first molars and restricted the anterior displacement of the maxilla, without significantly affecting the GoGn.SN angle.

摘要
研究目的：评估仅采用颈牵引头帽（cervical headgear）治疗安氏II类1分类错𬌗（Class II division 1 malocclusion）患者15±4个月时所引发的牙列与骨骼变化。
研究方法：纳入处于生长发育期的安氏II类1分类错𬌗患者作为实验组（EG，n=23），对其接受颈牵引头帽治疗的初始时刻（T1）与治疗即刻结束后（T2）的头影测量指标差异进行检测，并在匹配周期内，与另一组错𬌗类型、实足年龄均匹配的未治疗个体组成的对照组（CG，n=22）的相关指标进行对比。本次评估的头影测量变量包括：ANB角、GoGn.SN、AO-BO、S'-ANS、S'-A、S'-B、S'-Pog及S'-U6（上颌第一磨牙）。采用夏皮罗-威尔克（Shapiro-Wilk）检验与莱文（Levene）检验对研究结果进行统计学评估。
研究结果：对比两组在T1与T2时点的相关指标，发现ANB、S'-U6、AO-BO、S'-ANS、S'-A、S'-B及S'-Pog变量存在显著统计学差异；而GoGn.SN角未观察到具有统计学意义的变化。
研究结论：颈牵引头帽的单独使用可促进上颌第一磨牙远移，并限制上颌骨的向前移位，且未对GoGn.SN角产生显著影响。