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ABSTRACT: To evaluate the soft profile and hard tissue changes after maxillary protraction with skeletal anchorage implant in treatment of Class III malocclusion during growth period.
18 patients with skeletal Class III malocclusion were treated with maxillary protraction for about 9 months, (3.5 +/- 0.1) N, with skeletal anchorage implant and face mask. Cephalometric records were analyzed to assess the changes of maxillo-facial structure of the hard and soft tissue before and after treatment.
All patients' Class III profiles were corrected. Maxillary growth increased, chin clockwise rotated, facial convexity angle increased, lower lip protrusion decreased. Facial vertical height ratio, nasolabial angle, upper lip protrusion and mentolabial sulcus changed unconspicuously. Upper incisors kept in sites, lower incisor upright, maxilla moved forwards. SNA, ANB significantly increased. SNB decreased and the mandible clockwise rotated.
The maxilla is effectively protracted without significant rotation by using skeletal anchorage implant. The undesired effects of conventional protraction therapies, such as labial tilt of upper anterior teeth and extrusion of the maxillary molars, are reduced or eliminated with skeletal anchorage implant. These effects can conspicuously correct profiles of the patients with skeletal Class III malocclusion, make the profile more harmonious and aesthetic.
Hua xi kou qiang yi xue za zhi = Huaxi kouqiang yixue zazhi = West China journal of stomatology 06/2012; 30(3):278-82.
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ABSTRACT: Momordica charantia L., a genus of Momordica Linn. of the family Cucurbitaceae, commonly known as bitter melon, has been widely planted in China, Southeast Asia, Turkey and other areas, and has been used as a medicine for a long time. Alpha-momorcharin (α-MMC) extracted and purified from bitter melon seeds has significant anti-tumor and anti-virus effects, and has potential toxicity as well, especially when taken overdose. However, up to date studies on its safety evaluation are still insufficient.
The immunogenicity, immunotoxicity and general toxicity of α-MMC were investigated in rats and guinea-pigs, and the potential toxic effects of the agent on the body were also examined.
The major ribosome-inactivating protein was isolated by column chromatographies from the protein extracted from bitter melon seeds, and was verified as α-MMC. After rats were immunized by α-MMC, titers of specific antibody to α-MMC in immunized rats serum were detected by indirect ELISA. Guinea-pigs and rats immunized with α-MMC were used to evaluate the active systemic anaphylaxis and passive cutaneous anaphylaxis induced by α-MMC relatively. α-MMC of 6.25 mg/kg, 2.08 mg/kg and 0.70 mg/kg was administered to rats every 2 days. Five weeks later, animals were sacrificed, and then, biochemical examination, analysis of bone marrow and peripheral blood cells, and histopathologic examination were performed.
The ribosome-inactivating protein isolated and purified from bitter melon seeds was identified as α-MMC. It induced high titer (1:46.4) of specific IgG and high positive results of the active systemic anaphylaxis and passive cutaneous anaphylaxis tests in animals. With the time of the α-MMC administration increasing, the body weights of the animals administered with α-MMC of 6.25 mg/kg decreased significantly, and point necrosis was also observed in liver cells, along with abnormal findings in serum chemistry, hematology and bone marrow histopathology test. The toxic effect lessened with the decrease of the dose of α-MMC and further reduced after the convalescence stage.
The results of the study show that α-MMC has high immunogenicity and immunotoxicity, and can cause obvious organic liver lesion.
Journal of ethnopharmacology 12/2011; 139(2):590-8. · 2.32 Impact Factor
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ABSTRACT: To investigate the magnitude and pattern of tooth movement in class II division 1 malocclusion cases treated with extraction of upper first and lower second premolars.
Thirty cases of class II division 1 malocclusion were examined with pre- and post-treatment lateral cephalometric radiographs. The movement of both front and posterior teeth, on both upper and lower jaws were measured and compared.
The crowns of the upper and lower central incisors moved distally for (3.59 +/- 2.39) mm and (2.32 +/- 1.58) mm, respectively. The root apexs moved distally for (1.19 +/- 2.44) mm and (1.56 +/- 0.98) mm. The labial inclinations of the upper and lower central incisors decreased by 9.87 degrees +/- 7.68 degrees and 2.64 +/- 3.99 degrees. The crowns of the upper and lower first molars moved mesially for (4.32 +/- 4.87) mm and (4.38 +/- 1.46) mm, respectively. The buccal root apexs moved mesially for (2.74 +/- 1.56) mm and (4.43 +/- 2.12) mm. The upper and lower first molars rotated 3.90 degrees +/- 4.55 degrees and 1.25 degrees +/- 6.06 degrees counterclockwisely. The changes were statistically significant (P<0.05).
The ratio of front and posterior teeth movement is 1 : 1.3 for maxillary teeth and 3 : 5 for mandibular teeth. Upper incisors move as controlled tipping and lower incisors exhibit bodily movement.
Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 11/2011; 42(6):838-41.
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ABSTRACT: To detect myofibroblast formation on the tension side during orthodontic tooth movement in vivo and myofibroblast expression of alpha-smooth muscle actin (alpha-SMA) induced by tension both in vivo and in vitro.
Fifty 6-week male rats were used in this in vivo study, and the right maxillary first molar was moved mesially, which served as the experimental group, and the left maxillary first molar served as the control. Rats were sacrificed at days 0, 3, 5, 7, and 14 after force loading. Myofibroblasts, identified with alpha-SMA, were examined through immunohistochemistry. For the in vitro study, human periodontal ligament (PDL) fibroblasts were obtained. Cyclic mechanical tension was applied to the fibroblasts for 0, 1, 3, 6, and 12 hours. Transmission electron microscopy was used to detect the ultrastructure of myofibroblasts. alpha-SMA mRNA gene expression was quantified by real-time quantitative PCR. The expression of alpha-SMA was detected by immunofluorescence and quantified by Western blotting.
In vivo, the myofibroblasts expressing alpha-SMA were identified both in the experimental group and in the control group. The expressions of alpha-SMA were increased in the tension areas of the experimental group over time, and reached the maximum in day 14. In vitro, fibronexus junctions and actin microfilaments in the cells could be found with transmission electron microscopy. Cyclic mechanical tension could significantly induce alpha-SMA expression at 12 hours (P < .01) than the controls.
Myofibroblasts existed in the PDL. The expressions of alpha-SMA in the myofibroblasts were significantly up regulated under tension both in vivo and in vitro.
The Angle Orthodontist 09/2010; 80(5):912-8. · 1.21 Impact Factor
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ABSTRACT: To investigate the expression of osteocalcin during rapid orthodontic tooth movement aided by alveolar surgery in beagle dogs.
Eight male beagles were used, and bilateral mandibular second premolars were extracted for distalization of the first premolars against the third premolars by orthodontic NiTi coil spring with a force of 100 gm. Right and left mandibular sides were randomly assigned to experimental and sham sides, and alveolar surgery was performed only on the experimental side to reduce the osteal resistance on the mesial side of the extraction socket. Distance of tooth movement was measured once a week during the first 4 weeks. Two beagles were sacrificed after 1, 2, 4, and 8 weeks of orthodontic force application, and expression of osteocalcin was demonstrated by immunohistochemistry and quantified with computer-aided image analysis.
The average total movement of the first premolars in 4 weeks on the experimental side (1.868 +/- 0.022 mm) was approximately double that on the sham side (1.008 +/- 0.057 mm). As regards the average total anchorage loss, no significant difference (P > .05) was revealed. Dynamic osteocalcin concentrations presented at 4 time periods (P < .05). The staining intensity of osteocalcin on the experimental sides was higher than the corresponding sham sides, and that on the compression sites higher than the corresponding tension sites (P < .05).
The results suggested that alveolar surgery might serve as an effective and safe way to accelerate orthodontic tooth movement, and promote the rate of bone remodeling as revealed by the expression of osteocalcin.
Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 01/2009; 66(12):2467-75. · 1.58 Impact Factor
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ABSTRACT: To clarify the role of cementoblast in orthodontic-related root resorption, this study was attempted to examine whether murine cementoblast-like cells are responsive to mechanical stress, and how mechanical forces regulate bone sialoprotein (BSP) and osteopontin (OPN) gene expression in these cells in vitro. In this force-loading model, defined and reproducible mechanical loadings of different magnitudes and types were applied up to 24 h. Besides a transitory and reversible change in cell proliferation, remarkable alterations in gene transcription of BSP and OPN were found. BSP mRNA was suppressed by the stresses. Three and six hours-loadings at 2,000 microstrain up-regulated the expression of OPN mRNA, while the other loadings inhibited it. The study also concluded that 4,000 microstrain was likely to exert more influence on cementoblast-like cells than 2,000 microstrain. Furthermore, no obvious evidence indicated the difference between tension and compression. These results suggested that cementoblast-like cells are sensitive to mechanical stress, and may play a role in regulating orthodontic-related root resorption/repair.
Molecular Biology Reports 11/2008; 36(7):1741-8. · 2.93 Impact Factor
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ABSTRACT: To study the microstructue of acellular dermal matrix (ADM) and the attachment and proliferation of MG63 osteoblast-like cells on the membrane.
ADM was experimental group and expanded polytetrafluoroethylene (e-PTFE) membrane was control group. Light microscope and scanning electronic microscope (SEM) were used to observe the microstructure of the two kinds of membrane. MG63 osteoblast-like cells were cultured on the two kinds of membrane and the blank group. The cell viability was checked by cell viability analyzer (CVA) and alkaline phosphatase (ALP) activity was detected by ELISA. SEM was used to observe the adhesion and proliferation of the MG63 osteoblast-like cells on the two kinds of membrane.
The ADM was composed of the tissular side and basal lamina side. The tissue side showed scale-shaped structure and the basal lamina side demonstrated many digitations and some pores of folliculus pili. The e-PTFE showed many tiny lined cracks in elliptic structure. The viability of the MG63 osteoblast-like cells on the two kinds of membranes and ALP measurement showed that there was no significant difference between each of the two membrane groups and the blank. The adhesion and proliferation of osteoblast-like cells on the two kinks of membranes were both well.
ADM has no negative effects on the growth of osteoblast-like cells. ADM is biocompatibile and its microstructure is appropriate for guided bone regeneration materials.
Hua xi kou qiang yi xue za zhi = Huaxi kouqiang yixue zazhi = West China journal of stomatology 05/2008; 26(2):129-32.
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ABSTRACT: To investigate the bending mechanical properties and provide reference for orthodontists to select the proper wires during alignment stage.
In order to analyze the load deflection rate of NiTi round wire quantitatively, some NiTi round wires of different cross-sectional dimension (0.36, 0.41, 0.46 mm) were selected. Then loading-unloading experiments were carried out with the micro-orthodontic archwire testing apparatus and double end bending test could be accomplished with the wire in a 0.56 mm x 0.71 mm standard incisor edgewise bracket slot.
Under the load of 0.03 N.m, 0.36 and 0.41 mm NiTi round wire showed excellent super-elasticity, while 0.46 mm NiTi round wire didn't. When the optimal moment produced by the archwire was between 0.01 N.m and 0.02 N.m, the bending range of 0.36, 0.41 and 0.46 mm NiTi round wires was from 21.0 degrees to 49.5 degrees , 7.2 degrees to 23.7 degrees , and 6.5 degrees to 9.5 degrees , respectively after deducting the contact angle.
On the premises of yielding effective orthodontic force, the preferable NiTi round wire for alignment was the one which could produce continuous and slowly declining force.
Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology 10/2007; 42(9):525-8.
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ABSTRACT: To examine the proliferation of myofibroblast in periodental tension side of beagle dog during experimental tooth movement in orthodontics.
By the fixed orthodontic appliance, the five beagles were treated with 100 g forces that moved medially the maxillary first premolar, and the treatment lasted for four weeks. Using transmission electron microscope and immunohistochemistry, the proliferation of myofibroblast and expression of alpha-smooth muscle actin (alpha-SMA) were evaluated at week 1, 2, 3, 4 or 8 respectively after the orthodontic treatment.
During the total of four weeks, the expression of a-SMA increased in week 1 and reached the maximum in week 2; in week 4, the expression of alpha-SMA went back to normal level. Transmission electron microscopy showed that the myofibroblast contained the dense body appearing in cytoplasm.
The myofibroblast exists in periodontium and is concerned with the orthodontic tooth movement.
Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 02/2007; 38(1):123-5, 141.
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ABSTRACT: In order to evaluate the efficiency of Nd:YAG laser-aided ceramic brackets debonding technique, both ceramic brackets and metallic brackets were bonded with orthodontic adhesive to 30 freshly extracted premolars. The specimens were divided into three groups, 10 in each, according to the brackets employed and the debonding techniques used: (1) metallic brackets with shear debonding force, (2) ceramic brackets with shear debonding force, and (3) ceramic brackets with Nd:YAG laser irradiation. The result showed that laser irradiation could diminish shear bond strength (SBS) significantly and produce the most desired ARI scores. Moreover, scanning electron microscopy investigation displayed that laser-aided technique induced little enamel scratch or loss. It was concluded that Nd:YAG laser could facilitate the debonding of ceramic brackets and diminish the amount of remnant adhesive without damaging enamel structure.
Applied Surface Science 255(2):613-615. · 2.10 Impact Factor
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ABSTRACT: This study investigated the bioactivity and biocompatibility of hydroxyapatite nanoparticles (n-HA)/Polyamide-66 (PA66) nanocomposite membrane and expanded-polytetrafluoroethylene (e-PTFE) membrane (as control) to MG63 osteoblast-like cells. The attachment and proliferation of the cells on the porous surface of nHA/PA66 membrane and the surface of e-PTFE membrane were evaluated by scanning electron microscope (SEM) observation and the MTT assay. The bioactivity of the cells on the surface of the two membranes was evaluated by testing cell viability and alkaline phosphatase (ALP) activities. The results suggested that the bioresponse of MG63 osteoblast-like cells on the porous surface of nHA/PA66 membrane was better than the bioresponse on the opposite surface of e-PTFE membrane. Because of a better cell attachment manner, there is a potential utilization of the guided bone regeneration (GBR) membrane to substitute nHA/PA66 membrane for e-PTFE membrane.
Applied Surface Science 255(2):267-269. · 2.10 Impact Factor
