Cozza Paola, Baccetti Tiziano, Franchi Lorenzo, McNamara James A
Department of Orthodontics, University of Rome Tor Vergata, Rome, Italy.
Am J Orthod Dentofacial Orthop. 2006 Jun;129(6):734-9. doi: 10.1016/j.ajodo.2006.02.004.
The aim of this study was to investigate the effectiveness of a quad-helix/crib (Q-H/C) appliance in a group of growing subjects with thumb-sucking habits and both dental and skeletal open bites.
The records of 23 subjects treated with Q-H/C appliances were compared with a control group of 23 untreated subjects with similar vertical relationships. Lateral cephalograms were analyzed before treatment (T1; mean age, 8.4 +/- 1.4 years) and immediately after treatment (T2; mean age, 9.9 +/- 1.5 years). Mean duration of treatment was 1.5 +/- 7 months. The T2-T1 changes in the 2 groups were compared with a nonparametric test for independent samples (Mann-Whitney U test).
The average increase in overbite during Q-H/C therapy (3.6 mm more than the control group) overcorrected the amount of anterior open bite at T2. However, 4 of 23 subjects did not show positive overbites at T2. Both the maxillary and mandibular incisors had significantly greater lingual inclinations (about 4.0 degrees) associated with greater extrusion (1.4 and 1.0 mm, respectively) in the Q-H/C group than in the control group. In addition, the treated group showed a greater downward rotation (1.2 degrees) of the palatal plane than did the control group. This change was associated with a greater increase in upper anterior facial height (0.7 mm) and a clinically significant reduction in the palatal plane-mandibular plane angle (-1.7 degrees) in the Q-H/C group with respect to the controls. The upper and lower lips showed significant tendencies toward retraction relative to the E-plane in the treated group (2.6 and 2.9 mm, respectively) compared with the controls.
The Q-H/C appliance was effective in correcting the dental open bite in 90% of growing subjects with thumb-sucking habits and dentoskeletal open bites. The Q-H/C protocol produced a clinically significant improvement in the vertical skeletal relationships because of downward rotation of the palatal plane.
本研究的目的是调查四螺旋/矫治器（Q-H/C）对一组有吮拇指习惯且存在牙性和骨性开牙合的生长发育期受试者的疗效。
将23例接受Q-H/C矫治器治疗的受试者记录与23例未经治疗、垂直关系相似的对照组受试者记录进行比较。在治疗前（T1；平均年龄8.4±1.4岁）和治疗后即刻（T2；平均年龄9.9±1.5岁）分析头颅侧位片。平均治疗持续时间为1.5±7个月。采用独立样本非参数检验（曼-惠特尼U检验）比较两组T2-T1的变化。
Q-H/C治疗期间覆盖平均增加量（比对照组多3.6 mm）对T2时的前牙开牙合量进行了过度矫正。然而，23例受试者中有4例在T2时未显示出正覆盖。与对照组相比，Q-H/C组上颌和下颌切牙舌倾度明显更大（约4.0度），伴有更大的伸长（分别为1.4和1.0 mm）。此外，治疗组腭平面向下旋转（1.2度）比对照组更大。这种变化与Q-H/C组相对于对照组上前部面部高度更大增加（0.7 mm）以及腭平面-下颌平面角临床上显著减小（-1.7度）相关。与对照组相比，治疗组上、下唇相对于E平面有明显的后缩趋势（分别为2.6和2.9 mm）。
Q-H/C矫治器对90%有吮拇指习惯且存在牙颌面开牙合的生长发育期受试者的牙性开牙合有效。由于腭平面向下旋转，Q-H/C方案在垂直骨骼关系方面产生了临床上显著的改善。
