| Summary: | 碩士 === 長庚大學 === 顱顏口腔醫學研究所 === 102 === INTERDENTAL OSTEOTOMIES INDUCE REGIONAL ACCELERATORY PHENOMENON AND ACCELERATE ORTHODONTI TOOTH MOVEMENT
BACKGROUND AND PURPOSE：Although it has been revealed clinically that double-jaw orthognathic surgery induces systemic increase of baseline bone turnover and subsequently accelerates the postoperative orthodontic tooth alignment, it is not clear whether a smaller extent jaw bone osteotomy, such as an interdental osteotomy, is intensive enough to accelerate the postoperative orthodontic tooth alignment.
METHODS：Twelve adult male beagle dogs were randomly assigned into 2 groups. The sham control group (N=6) received orthodontic tooth alignment of the maxillary incisors, and the experimental group (N=6) received orthodontic tooth alignment of the maxillary incisors and interdental osteotomies between the maxillary 3rd incisor and canine on both sides at the same time when the orthodontic tooth alignment was commenced. The orthodontic tooth alignment was 3 months in both groups. Records of cone beam CT of the maxilla, dental casts, blood samples, and gingival crevicular fluid (GCF) of the maxillary incisors were taken right before the orthodontic tooth alignment (T0), 1 week (T1), and 1 (T2), 2 (T3), &; 3 (T4) months after commencing the orthodontic tooth alignment. They were analyzed respectively for the changes of interdental alveolar bone gray scale (osteoporosity) of maxillary incisors, irregularity index (rate of orthodontic tooth alignment), and the bone specific alkaline phosphatase (bALP, a biomarker for osteoblastic activity) and C-terminal telopeptide of type I collagen (ICTP, a biomarker for osteoclastic activity) in the serum and GCF samples from T0 to T4. The data were analyzed statistically for the inter- and intra-group differences.
RESULTS：The rate of orthodontic tooth alignment of the experimental group was significantly greater and 2-fold of that of the sham control group at T1, T2, T3, and T4. The serum-bALP, serum-ICTP, GCF-bALP, GCF-ICTP, and osteoporosity remained similarly from T0 to T4 in the sham control group. Whereas the GCF-bALP increased 2- to 3-folded from T1 to T4, the GCF-ICTP increased 5-folded at T1 then gradually decreased from T2 to T4, and the interdental osteoporosity significantly increased from T1 to T4, but the serum-bALP and serum-ICTP remained similar without significant changes in the experimental group.
CONCLUSIONS：The interdental osteotomy induces regional but not systemic acceleratory phenomenon, and is intensive enough to accelerate postoperative orthodontic tooth alignment 2 folds. The intensity of increase of bone turnover rate and osteoporosity might depend on the extent of osteotomy.
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