不同型号记忆合金牵张器对牙槽嵴增高高度的影响

Effects of Different TiNi-SMA Distractor on the Height of Alveolar Ridge Augmentation

目的 探讨不同牵张力、不同固定脚间距的钛镍记忆合金牵张器对牙槽嵴增高高度的影响。方法 用钛 镍记忆合金丝加工成A、B、C3种不同型号的牵张器,其固定脚间距和最大复形力分别为20mm、700g,15mm、 1000g,20mm、1000g。选用成年杂种犬15只,按使用牵张器型号随机分为A、B、C组,拔除两侧下颌全部前磨牙和 第一磨牙,1个月后用不同的全埋置的钛镍记忆合金牵张器完成牵张手术。在术前及术后5周连续测量术区颌骨 高度,拍摄X线片。结果 A、B、C组在术后1周牙槽嵴增高的高度分别为(7.55±1.02)mm、(4.97±0.34)mm、(8.54 ±0.82)mm,5周时为(7.20±1.05)mm、(4.93±0.21)mm、(8.04±0.78)mm。A、C组增高的高度间差异无统计学意 义,B组与其他两组间的差异有统计学意义,组内术后不同时期的高度差异无统计学意义。X线片可见术后有明显 的牵张间隙,5周时牵张区骨密度增高,有新骨生成。结论 在允许的牵张力范围内,牙槽嵴增高的高度与钛镍记 忆合金牵张器的大小即固定脚间距有关。

Objective To discuss the effects of titanium nickel shape memory alloy (TiNi-SMA) distractor with different stretching force and different distance between two fixed ends on the height of alveolar ridge augmentation.Methods The mini distractors were all made of TiNi-SMA wire. The maximum stretching force and the distance between two fixed ends according to different distractors (A, B and C) were 20 mm, 700 g; 15 mm, 1 000 g; 20 mm, 1 000 g. 15 adult mongrel canines were divided into three groups randomly and extracted the mandibular premolars and first molar. One month later, box-shaped osteotomies of the alveolar bone were carried out in the left mandible and the TiNi-SMA distractors were buried. The bone height was measured and the radiographs were taken before and five weeks post operation continuously.Results One week post operation, the vertical ridge augmentation of group A, B and C averaged (7.55±1.02)mm, (4.97±0.34)mm, (8.54±0.82)mm and the height remained (7.20±1.05)mm, (4.93±0.21)mm, (8.04±0.78)mm five weeks post operation. There was no statistic difference in the height of alveolar ridge augmentation between Group A and C, but Group B showed significant difference with the other two groups. In each group, the height did not changed significantly with the time. The radiographs showed obvious distraction gap post operation, and the new bone regenerated five weeks later.Conclusion It suggests that in the scope of suitable stretching force, the height of alveolar ridge augmentation was determined by the size of TiNi-SMA distractor, that is to say, determined by the distance between the two fixed ends.