Faltin Kurt Júnior, Faltin Rolf M, Baccetti Tiziano, Franchi Lorenzo, Ghiozzi Bruno, McNamara James A
Department of Orthodontics, School of Dentistry, University Paulista, São Paulo, Brazil.
Angle Orthod. 2003 Jun;73(3):221-30. doi: 10.1043/0003-3219(2003)073<0221:LEATTF>2.0.CO;2.
The aim of the present investigation was to provide information about the long-term effects and optimal timing for class-II treatment with the Bionator appliance. Lateral cephalograms of 23 class-II patients treated with the Bionator were analyzed at three time periods: T1, start of treatment; T2, end of Bionator therapy; and T3, long-term observation (after completion of growth). T3 includes a phase with fixed appliances. The treated sample was divided into two groups according to their skeletal maturity as evaluated by the cervical vertebral maturation (CVM) method. The early-treated group (13 subjects) initiated treatment before the peak in mandibular growth, which occurred after completion of Bionator therapy. The late-treated group (10 subjects) received Bionator treatment during the peak. The T1-T2, T2-T3, and T1-T3 changes in the treated groups were compared with changes in control groups of untreated class-II subjects by nonparametric statistics (P < .05). The findings of the present study on Bionator therapy followed by fixed appliances indicate that this treatment protocol is more effective and stable when it is performed during the pubertal growth spurt. Optimal timing to start treatment with the Bionator is when a concavity appears at the lower borders of the second and the third cervical vertebrae (CVMS II). In the long-term, the amount of significant supplementary elongation of the mandible in subjects treated during the pubertal peak is 5.1 mm more than in the controls, and it is associated with a backward direction of condylar growth. Significant increments in mandibular ramus height also were recorded.
本研究的目的是提供有关使用Bionator矫治器进行II类错颌治疗的长期效果及最佳时机的信息。对23例使用Bionator矫治器治疗的II类患者的头颅侧位片在三个时间段进行分析：T1，治疗开始时；T2，Bionator治疗结束时；T3，长期观察期（生长完成后）。T3包括使用固定矫治器的阶段。根据颈椎成熟度（CVM）方法评估的骨骼成熟度，将治疗样本分为两组。早期治疗组（13名受试者）在Bionator治疗结束后出现的下颌生长高峰期之前开始治疗。晚期治疗组（10名受试者）在高峰期接受Bionator治疗。通过非参数统计（P < 0.05）将治疗组的T1-T2、T2-T3和T1-T3变化与未经治疗的II类受试者对照组的变化进行比较。本研究关于Bionator治疗后使用固定矫治器的结果表明，该治疗方案在青春期生长高峰期进行时更有效且稳定。开始使用Bionator治疗的最佳时机是第二和第三颈椎下缘出现凹陷时（CVMS II）。从长期来看，在青春期高峰期接受治疗的受试者中，下颌骨显著额外伸长的量比对照组多5.1毫米，并且与髁突向后生长方向有关。下颌升支高度也有显著增加。
