Ding Yuxiang, Li Guoquan, Zhang Xiaoyong, Ao Jianhua, Liu Wei, Ma Qin, Liu Yanpu, Liu Baolin
Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China.
J Oral Maxillofac Surg. 2009 Nov;67(11):2431-9. doi: 10.1016/j.joms.2009.05.441.
To make a preliminary study of the effect of low-intensity pulsed ultrasound on new bone formation during mandible distraction osteogenesis in dogs.
Bilateral surgical cuts were made in mandibles of 7 dogs between the first and second premolar regions. Anterior mandibles were lengthened by 20 mm at the rate of 1 mm/day twice a day. During the distraction period 1 lateral distraction gap was irradiated by low-intensity pulsed ultrasound for 10 minutes twice a day and the other side was sham irradiated as control. After distraction was completed, the dogs were sacrificed at 0, 1, 2, 4, 6, 8, and 12 weeks. Before sacrifice, dynamic bone imaging with technetium (99)m-methylene diphosphonate ((99)mTc-MDP) single-photon emission computed tomography was performed. Mandible samples were harvested. Then plain x-ray, dual-energy x-ray bone mineral density measurement, 3-dimensional computed tomography, and regular histologic examination were performed.
The (99)mTc-MDP bone imaging showed that uptake of (99)mTc-MDP in the experimental side was higher than in the control side at the early period of the consolidation time, but the outcome was later reversed. Plain x-ray showed that new bone of the experimental side was mature sooner than that of the control side. Bone mineral density in the experimental side was higher than that of the control side. Volume of new bone of the 2 sides had no significant difference. Histologic examination showed that trabeculae of the experimental side were more numerous and thicker than those of the control side at the early period of the consolidation time. Endochondral bone formation was observed in the experimental side.
Low-intensity pulsed ultrasound could accelerate bone formation during mandibular distraction osteogenesis and increase bone mineral density but had no effect on the volume of new bone.
初步研究低强度脉冲超声对犬下颌骨牵张成骨过程中新骨形成的影响。
在7只犬的下颌骨第一和第二前磨牙区域之间进行双侧手术切口。下颌前部以每天1毫米、每天两次的速度延长20毫米。在牵张期，一侧牵张间隙每天接受两次低强度脉冲超声照射，每次10分钟，另一侧作为对照进行假照射。牵张完成后，在0、1、2、4、6、8和12周处死犬。处死前，用锝（99）m-亚甲基二膦酸盐（（99）mTc-MDP）单光子发射计算机断层扫描进行动态骨成像。采集下颌骨样本。然后进行普通X线检查、双能X线骨密度测量、三维计算机断层扫描和常规组织学检查。
（99）mTc-MDP骨成像显示，在愈合早期，实验组（99）mTc-MDP摄取高于对照组，但结果后来逆转。普通X线显示，实验组新骨比对照组成熟得更快。实验组骨密度高于对照组。两侧新骨体积无显著差异。组织学检查显示，在愈合早期，实验组小梁比对照组更多、更厚。实验组观察到软骨内成骨。
低强度脉冲超声可加速下颌骨牵张成骨过程中的骨形成并增加骨密度，但对新骨体积无影响。
