Rapid tooth movement through distraction osteogenesis of the periodontal ligament in dogs.
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.
Ai
Hong
H
Department of Stomatology, Sun Yat-sen University, Third Affiliated Hospital, Guangzhou, Guangdong 510630, China. aih_5@hotmail.com
Xu
Qing-feng
QF
Lu
Hong-fei
HF
Mai
Zhi-hui
ZH
An
Ai-qun
AQ
Liu
Guo-ping
GP
D000818:Animals; D004285:Dogs; D008297:Male; D019857:Osteogenesis, Distraction / Q000379:methods*; D010513:Periodontal Ligament / Q000502:physiology / Q000601:surgery*; D012391:Root Resorption / Q000209:etiology; D014087:Tooth Movement Techniques / Q000379:methods*