Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling m...Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement,while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks,followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly,and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However,there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.展开更多
Objective． An internal fixation apparatus—— distraction reduction fixation system(DRFS) was designed to satisfy the clinical needs for spondylolisthesis. Methods. Since 1996, 53 patients were treated with DRFS. Amo...Objective． An internal fixation apparatus—— distraction reduction fixation system(DRFS) was designed to satisfy the clinical needs for spondylolisthesis. Methods. Since 1996, 53 patients were treated with DRFS. Among them, 35 had spondylolisthesis, 12 had lumbar canal stenosis accompanied with instability, 2 had vertebral tumors and 4 suffered from spinal fracture. The average age was 53.6 years old (ranged 24～ 72yrs). The mean time for follow- up was 30.6 months (16～ 44 months). Results． The slip rate was 0.15± 0.10 before operation, and decreased to 0.09± 0.07 after operation. Entire slip reposition was achieved in 19 cases (54.3％ ). The change in height of the intervertebral space within the fixation segments was 0.7± 0.17. Conclusion． DRFS achieved better results for spondylolisthesis less II degree and no other adverse effects were found. Compared with other foreign and domestic techniques, it had advantages in less implants, less operation gears required and ease to utilize in operation. It was proved to be an ideal internal fixation apparatus.展开更多
基金supported by the Traditional Chinese Medicine Research Fund of the Administration of Traditional ChineseMedicine of Shaanxi Province (jc34)
文摘Objective To investigate the histological changes of rapid tooth movement in dogs treated by resistance reduction and distraction osteogenesis,aiming to establish an animal model and further to reveal the remodeling mechanism of rapid tooth movement. Methods A total of 8 local hybrid dogs were selected as subjects for this study. The second pre-molar was extracted on both sides. The experimental side underwent alvelor surgery for resistance reduction and a home-made tooth-borne intraoral distraction device was installed for rapid tooth movement,while for the other side (control side) only tooth-borne intraoral distraction device was used for rapid tooth movement. The longest active force-delivery span was 2 weeks,followed by 6-week retention. The distance between the moved tooth and anchor unit was recorded weekly,and radiography was performed for each side before and after distraction. The surrounding tissues including periodontal ligament and alveolar bone were sectioned for histological analysis. Results The average distance of tooth movement was 3.55mm on the experimental side and 1.11mm on the control side. The rate of tooth movement was notably higher (P<0.01) and no significant apical root resorption was detected by X-ray on the experimental side. The active alvelor bone remodeling was found on the tension and pressure sides. However,there was no significant difference between the experimental side and the control side after the retention period. Conclusion The rate of orthodontic tooth movement can be accelerated through resistance reduction and periodontal distraction without any unfavorable effects but at minimal anchorage loss.
文摘Objective． An internal fixation apparatus—— distraction reduction fixation system(DRFS) was designed to satisfy the clinical needs for spondylolisthesis. Methods. Since 1996, 53 patients were treated with DRFS. Among them, 35 had spondylolisthesis, 12 had lumbar canal stenosis accompanied with instability, 2 had vertebral tumors and 4 suffered from spinal fracture. The average age was 53.6 years old (ranged 24～ 72yrs). The mean time for follow- up was 30.6 months (16～ 44 months). Results． The slip rate was 0.15± 0.10 before operation, and decreased to 0.09± 0.07 after operation. Entire slip reposition was achieved in 19 cases (54.3％ ). The change in height of the intervertebral space within the fixation segments was 0.7± 0.17. Conclusion． DRFS achieved better results for spondylolisthesis less II degree and no other adverse effects were found. Compared with other foreign and domestic techniques, it had advantages in less implants, less operation gears required and ease to utilize in operation. It was proved to be an ideal internal fixation apparatus.
