el-Bialy Tarek H, el-Moneim Zaki Abd, Evans Carla A
Department of Orthodontics, Tanta University, Egypt.
Am J Orthod Dentofacial Orthop. 2003 Oct;124(4):427-34. doi: 10.1016/s0889-5406(03)00408-6.
Therapeutic ultrasound is known to enhance bone-fracture healing. The purpose of this article was to study the effect of therapeutic ultrasound on mandibular incisor development and eruption in 15 skeletally mature male New Zealand white rabbits undergoing mandibular osteodistraction. The surgical cuts were made anterior to the molars and consequently transected the mandibular incisors. The animals were divided into 3 groups of 5 rabbits each. Group I received ultrasound on both sides of the mandible every other day. Group II received ultrasound on the left side of the mandible every day. Group III did not receive ultrasound. Ultrasound was given for 20 minutes per application. Mandibular incisor eruption was measured directly on the rabbits and on lateral head radiographs. The animals were killed 4 weeks after surgery, and dissected mandibular specimens that contained the incisor segments were evaluated histologically. The lengths of the tooth segments increased in the ultrasound-treated animals, compared with the controls (group III). However, the rabbits in group II had greater increases in length of the mandibular incisor segments than those in group I. Histologic examination showed that the newly formed tissues at the distraction site and at the cut ends of the incisor segments consisted of osteodentin-like tissue and cementum. Thus, therapeutic ultrasound combined with distraction enhanced mandibular incisor growth and eruption.
已知治疗性超声可促进骨折愈合。本文旨在研究治疗性超声对15只骨骼成熟的雄性新西兰白兔下颌骨牵张成骨过程中下颌切牙发育和萌出的影响。手术切口位于磨牙前方，因此切断了下颌切牙。将动物分为3组，每组5只。第一组每隔一天在下颌两侧接受超声治疗。第二组每天在下颌左侧接受超声治疗。第三组不接受超声治疗。每次超声治疗20分钟。直接在兔子身上和头部侧位X线片上测量下颌切牙的萌出情况。术后4周处死动物，对包含切牙段的下颌骨标本进行组织学评估。与对照组（第三组）相比，接受超声治疗的动物切牙段长度增加。然而，第二组兔子下颌切牙段长度的增加幅度大于第一组。组织学检查显示，牵张部位和切牙段断端新形成的组织由类骨牙本质组织和牙骨质组成。因此，治疗性超声联合牵张可促进下颌切牙的生长和萌出。
