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Objective To observe the maxillary alveolar cortical bone and cancellous bone mineral density of patients with different degree of dental fluorosis.Methods According to the diagnostic criteria of dental fluorosis (WS/T 208-2011),from March 2015 to March 2017,30 orthodontic dental fluorosis patients were selected in Guiyang Stomatological Hospital.According to the degree of tooth damage,patients were divided into mild,moderate and severe fluorosis groups,10 cases per group;10 normal orthodontic patients were selected as control group.A cone beam computed tomography (CBCT) was taken preoperatively to measure the CT values (the attenuation value after absorption of X-rays through the tissue,HU) of buccal alveolar cortical bone and cancellous bone density in incisor,canine,premolar,and molar areas.Results The buccal alveolar cortical bone densities of incisor [(1 155.6 ± 80.7),(1 048.8 ± 106.7),(885.1 ± 118.1),(589.7 ± 104.6) HU],canine [(1 221.0 ± 76.l),(1 054.6 ± 95.3),(913.3 ± 109.4),(608.5 ± 131.4) HU],premolar [(1 173.5 ± 91.2),(1 020.9 ± 113.3),(894.5 ± 107.9),(593.5 ± 119.7) HU],and molar [(1 113.6 ± 89.5),(1 017.2 ± 101.3),(877.2 ± 102.9),(609.1 ± 113.5) HU] areas in control,mild,moderate and severe fluorosis groups,were significantly different statistically (F =45.557,51.411,61.200,56.845,P ＜ 0.01),CT values of dental fluorosis group were significant lower than that of control group (P ＜ 0.05).The cancellous bone mineral density of the incisor [(633.4 ± 67.7),(556.8 ± 80.1),(473.1 ± 71.7),(358.8 ± 98.7) HU],canine [(644.9 ± 70.1),(570.6 ± 73.3),(490.0 ± 85.2),(361.1 ± 93.8) HU],premolar [(630.5 ± 72.5),(554.5 ± 70.7),(477.7 ± 84.0),(353.6 ± 101.4) HU],and molar [(637.6 ± 79.8),(558.5 ± 84.3),(471.7 ± 72.8),(367.7 ± 88.7) HU] areas in control,mild,moderate and severe fluorosis groups,were significantly different statistically (F =20.183,20.245,22.751,21.268,P ＜ 0.01),CT values of dental fluorosis group were significant lower than that of control group (P ＜ 0.05).Conclusion The bone density of maxillary alveolar cortical bone and cancellous bone is reduced in dental fluorosis patients.
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Objective:To evaluate facial soft tissue 3-deminsion changes of skeletal Class Ⅲmalocclu-sion patients after orthognathic surgery using structure light scanning technique .Methods:Eight patients [3 males and 5 females, aged ( 27.08 ±4.42 ) years ] with Class Ⅲ dentoskeletal relationship who underwent a bimaxillary orthognathic surgical procedure involving advancement of the maxilla by Le FortⅠosteotomy and mandibular setback by bilateral sagittal split ramus osteotomy (BSSO) and genioplasty to correct deformity were included .3D facial images were obtained by structure light scanner for all the patients 2 weeks preoperatively and 6 months postoperatively .The facial soft tissue changes were evalua-ted in 3-dimension.The linear distances and angulation changes for facial soft tissue landmarks were ana-lyzed.The soft tissue volumetric changes were assessed too .Results: There were significant differences in the sagittal and vertical changes of soft tissue landmarks .The greatest amount of soft tissue change was close to lips.There were more volumetric changes in the chin than in the maxilla , and fewer in the forehead .Conclusion: After biomaxillary surgery , there were significant facial soft tissue differences mainly in the sagittal and vertical dimension for skeletal Class Ⅲ patients .The structure light 3 D scan-ning technique can be accurately used to estimate the soft tissue changes in patients who undergo orthog-nathic surgery .
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<p><b>OBJECTIVE</b>To investigate the synergistic effect of transforming growth factor-beta1 (TGF-beta1) and platelet-derived growth factor-BB (PDGF-BB) on the expression of integrin beta3, in periodontal membrane of rat orthodontic tooth.</p><p><b>METHODS</b>An orthodontic tooth movement model was established. Up to 32 experimental rats were randomly divided into four groups according to a random number table. The four groups were injected with 1% PBS, TGF-beta1 (5 ng), PDGF-BB (10 ng), and combined TGF-beta1 (5 ng) and PDGF-BB (10 ng) in the buccal submucosal, respectively. The volume injected in each group was 0.1 mL. The animals were then sacrificed on the 10th day. The left maxillary first molar and periodontal tissue were taken. Different expressions of integrin beta3 were detected in periodontal tissues through immunohistochemistry. Mean optical density (OD) values of the positive fields were examined. The data obtained were analyzed through ANOVA. The data followed normal distribution, and were compared via t-test.</p><p><b>RESULTS</b>Compared with the control groups, the expression of integrin beta3 was higher in the experimental groupin tension sides (P < 0.01). Significant differences in tension sides between the single-injection groups and the combined group were observed (P < 0.01). Compared with the control groups, the expression of integrin beta3 was higher in the experimental group in compression sides (P < 0.05). In addition, there was no significant differences in compression sides between the single-injection groups and the combined group (P > 0.05).</p><p><b>CONCLUSION</b>In terms of local regulatory factors, TGF-beta1 combined with PDGF-BB enhance the expression of integrin beta3 in the periodontal membrane and accelerate periodontal remodeling. The synergistic effect of the two growth factors is better than the single growth factor.</p>
Subject(s)
Animals , Rats , Integrin beta3 , Molar , Periodontal Ligament , Platelet-Derived Growth Factor , Proto-Oncogene Proteins c-sis , Tooth Movement Techniques , Transforming Growth Factor beta1ABSTRACT
<p><b>OBJECTIVE</b>To investigate the combined effects of platelet-derived growth factor-BB (PDGF-BB) and insulin-like growth factor-I (IGF-I) on the expression of integrin (beta3 protein in the periodontal tissues of the compressing side of orthodontic tooth in rats.</p><p><b>METHODS</b>Establishing orthodontic movement model in Sprague-Dawley rats, which were injected with 10 ng PDGF-BB, 200 ng IGF-I alone or in combination in the buccal submucosal area of the orthodontic tooth. The injection was applied every other day. The experiment continued for ten days and then the rats were sacrificed. The expression of integrin (beta3 protein in periodontal ligament tissues of the compressing side was detected by immunohistochemical techniques.</p><p><b>RESULTS</b>The expression of integrin (beta3 protein in periodontal ligament tissues of the compressing side of each experimental group was significantly increased compared with that of the control group (P<0.01). Meanwhile the maximum mean optical density value of integrin (beta3 protein expression was attained in the combination group which showed a significant increase compared with the PDGF-BB group (P<0.05) and the IGF-I group (P<0.01).</p><p><b>CONCLUSION</b>The combination of exogenous PDGF-BB and IGF- I in orthodontic tooth movement may enhance the expression of integrin (beta3 protein in periodontal ligament cells and PDGF-BB and IGF-I may have a synergistic effect during orthodontic tooth movement.</p>