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
Background Animal models are needed for the study of rapid tooth movement into the extraction socket through distraction osteogenesis of the periodontal ligament. Methods Modified distraction devices were placed on ei...Background Animal models are needed for the study of rapid tooth movement into the extraction socket through distraction osteogenesis of the periodontal ligament. Methods Modified distraction devices were placed on eight dogs between the first and third mandibular premolars on the left sides; similar placement of traditional straight wise appliances on the right sides served as the control. The experimental distractors were activated （0.25 mm/d） twice a day and the control devices were activated （100 g） for two weeks with consolidation periods at weeks two, three, six, and ten. Two dogs were sacrificed at each consolidation time point; rates and patterns of tooth movement, loss of anchorage, and periapical films were evaluated, and the affected premolars and surrounding periodontal tissues were decalcified and examined histologically. General observations, X-ray periapical filming and histology examination were performed. Results Distal movement （（3.66±0.14） mm） measured two weeks after modified distraction exceeded that achieved using the traditional device （（1.15±0.21） mm; P 〈0.05）. Loss of anchorage was minimally averaged （0.34±0.06） mm and （0.32±0.07） mm in the experimental and control sides, respectively. By radiography, apical and lateral surface root resorptions on both sides were minimal. Alveolar bone lesions were never evident. Fibroblasts were enriched in periodontal ligaments and bone spicules formed actively along directions of distraction. Conclusions The canine model is suitable for the study of rapid tooth movement through distraction osteogenesis of the periodontal ligament. The technique accelerates tooth movement, periodontal remodeling, alveolar bone absorption, and may induce fibroblast formation, as compared to the traditional orthodontic method, without adversely affecting root absorption, bone loss, tooth mobility and anchorage loss.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Background Animal models are needed for the study of rapid tooth movement into the extraction socket through distraction osteogenesis of the periodontal ligament. Methods Modified distraction devices were placed on eight dogs between the first and third mandibular premolars on the left sides; similar placement of traditional straight wise appliances on the right sides served as the control. The experimental distractors were activated （0.25 mm/d） twice a day and the control devices were activated （100 g） for two weeks with consolidation periods at weeks two, three, six, and ten. Two dogs were sacrificed at each consolidation time point; rates and patterns of tooth movement, loss of anchorage, and periapical films were evaluated, and the affected premolars and surrounding periodontal tissues were decalcified and examined histologically. General observations, X-ray periapical filming and histology examination were performed. Results Distal movement （（3.66±0.14） mm） measured two weeks after modified distraction exceeded that achieved using the traditional device （（1.15±0.21） mm; P 〈0.05）. Loss of anchorage was minimally averaged （0.34±0.06） mm and （0.32±0.07） mm in the experimental and control sides, respectively. By radiography, apical and lateral surface root resorptions on both sides were minimal. Alveolar bone lesions were never evident. Fibroblasts were enriched in periodontal ligaments and bone spicules formed actively along directions of distraction. Conclusions The canine model is suitable for the study of rapid tooth movement through distraction osteogenesis of the periodontal ligament. The technique accelerates tooth movement, periodontal remodeling, alveolar bone absorption, and may induce fibroblast formation, as compared to the traditional orthodontic method, without adversely affecting root absorption, bone loss, tooth mobility and anchorage loss.
