Lau Eden Y, Sampson Wayne J, Townsend Grant C, Hughes Toby
School of Dentistry, The University of Adelaide, South Australia, Australia.
Aust Orthod J. 2009 May;25(1):48-58.
To evaluate the dentofacial changes and growth rotational responses of Angle Class II division 1 patients treated with the Clark twin block functional appliance.
This retrospective study comprised 13 boys (8.77 +/- 0.86 years) and 13 girls (8.75 +/- 0.70 years) treated by one orthodontist with the Clark twin block appliance. Selection was not biased by outcome and sample size power estimates exceeded 90 per cent. Tracings made on the pretreatment (T1), post-treatment (T2) and observation (T3) radiographs were superimposed on anatomically stable landmarks and the dentofacial changes and growth rotational responses compared. The data were tested for normal distribution and sexual dimorphism. Pearson correlation analyses of the treatment and observation phases were performed.
In light of the few sex differences and lack of any consistent trends, the data for the boys and girls were combined. Treatment reduced the overbite, overjet and achieved Class II correction through combinations of maxillary incisor uprighting (U1-SN: -5.3 +/- 5.30), lower incisor proclination (L1-MP: 6.6 +/- 6.80), facial height increase (AFH: 5.1 +/- 4.6 mm), ramal lengthening (Co-Go: 3.3 +/- 2.4 mm) and mandibular length increase (Co-Pog: 5.9 +/- 4.6 mm). During the observation period, similar growth changes were recorded, but the overbite (2.9 +/- 1.9 mm) and overjet (3.6 +/- 2.0 mm) increased due to some reversal of the treatment-induced incisor angulation changes. Over the treatment period (T1 to T2), the angles between the cranial base and maxillary (maxillary rotation) and mandibular stable structures (mandibular internal rotation) reduced by -0.1 +/- 1.2 degrees and -0.3 +/- 2.5 degrees, respectively. The angles between mandibular stable structures and Go-Me (mandibular external rotation) and SN-GoMe (mandibular total rotation) increased by 0.6 +/- 1.7 degrees and 0.9 +/- 2.1 degrees, respectively. Between T2 and T3, maxillary rotation, mandibular internal rotation and total mandibular rotation reduced -1.4 +/- 2.0 degrees, -2.4 +/- 2.5 degrees and -0.7 +/- 1.7 degrees, respectively. Mandibular external rotation increased -1.8 +/- 2.0 degrees. Mandibular total and internal rotation angles were significantly (p < 0.5) reduced at T2, but there were no significant associations between the rotations and dentofacial parameters during or following treatment.
On average, the maxillary and mandibular internal rotations were near zero during treatment, but the small and individually variable changes were not clearly associated with the Class II correction.
评估使用克拉克双阻板功能矫治器治疗的安氏II类1分类患者的牙颌面变化及生长旋转反应。
这项回顾性研究纳入了13名男孩（8.77±0.86岁）和13名女孩（8.75±0.70岁），均由一名正畸医生使用克拉克双阻板矫治器进行治疗。选择不受结果影响，样本量效能估计超过90%。将治疗前（T1）、治疗后（T2）和观察期（T3）的X线片描图叠加在解剖学稳定标志点上，比较牙颌面变化及生长旋转反应。对数据进行正态分布和性别差异检验。对治疗期和观察期进行Pearson相关性分析。
鉴于性别差异较少且无一致趋势，将男孩和女孩的数据合并。治疗通过上颌切牙直立（U1-SN：-5.3±5.30）、下颌切牙前倾（L1-MP：6.6±6.80）、面高增加（AFH：5.1±4.6mm）、升支延长（Co-Go：3.3±2.4mm）和下颌长度增加（Co-Pog：5.9±4.6mm）的组合，减少了覆合、覆盖并实现了II类错合的矫正。在观察期内，记录到了类似的生长变化，但由于治疗引起的切牙角度变化出现了一些逆转，覆合（2.9±1.9mm）和覆盖（3.6±2.0mm）增加。在治疗期（T1至T2），颅底与上颌（上颌旋转）和下颌稳定结构（下颌内旋转）之间的角度分别减少了-0.1±1.2度和-0.3±2.5度。下颌稳定结构与Go-Me（下颌外旋转）和SN-GoMe（下颌总旋转）之间的角度分别增加了0.6±1.7度和0.9±2.1度。在T2和T3之间，上颌旋转、下颌内旋转和下颌总旋转分别减少了-1.4±2.0度、-2.4±2.5度和-0.7±1.7度。下颌外旋转增加了-1.8±2.0度。下颌总旋转和内旋转角度在T2时显著减小（p<0.5），但在治疗期间或治疗后，旋转与牙颌面参数之间无显著相关性。
平均而言，治疗期间上颌和下颌内旋转接近零，但微小且个体差异的变化与II类错合矫正无明显关联。
