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Objective To explore a method of modified technique of sagittal split ramus osteotomy (SSRO) and to study the possibly more appropriate and effective methods for correction of mandibular de-formity. Methods 195 patients suffering from mandibular anomaly or accompanied by other deformities have been operated on by the modified or classical technique of SSRO. Results In the group of 105 cases treated by modified SSRO and the group of 90 classical SSRO, all the patients acheived excellent results. There was no statistic significance between the two groups. No complications occured, such as postopera-tive relapse, significant bleeding, postoperative infection, and others. Conclusion Since modified tech-nique of SSRO has more advantages than conventional classical technique, such as more area of bony con-tact, shorter-time operation, easier process: it is the preferred method for the correction of mandibular deformity. Accompanied by regularity and in time pre- and post-operational orthodontic therapy, it will be more widely used in the future.
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AIM:Titanium-Nickel shape memory alloy(TiNi-SMA) has memory,abradability and good biocompatibility. It has different osteotomy methods and biomechanics from routine distraction osteogenesis. In this study,the dog models of mandibular defects were established to explore the effect of TiNi-SMA distractor with different osteotomy methods on mandibular distraction osteogenesis. METHODS:The experiment was performed at the animal experimental center of Sun Yat-sen University from October to December 2005. ①Eight male adult Beagle canines of 12-14 kg were selected. A 1.5 cm?1.0 cm bone defect was made in bilateral mandible of each dog. The same size transport bone disc was created mesially by osteotomy on left side and corticotomy on right side. TiNi-SMA distractor was implanted to repair defect. ②One,four,and seven days,and nine weeks after operation,the canines were radiographed for histological analysis and bone formation was observed. RESULTS:Eight dogs were all included in the final analysis. ①Gross observation found the wounds healed well without infection in all experiment dogs. ②X-ray examination showed the bone transport disc on the right side of corticotomy moved to defect area gradually after operation and filled defect area on the whole on the 7th day after operation;The bone transport disc dislocated 1 day after operation and separated from defect area totally on the 7th day after operation on the side of osteotomy(left side). ③ Histological examination demonstrated bone formed in accordance with intramembranous ossification in distraction zone and bony connection between the transport disc and mesial mandible on right side;On the left side,there was a big defect at the area of both distraction and defect zone because of dislocated bone transport disc,and no obvious new bone regeneration was found. CONCLUSION:Corticotomy can be used to establish a successfully canine model of mandibular distraction osteogenesis.
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<p><b>OBJECTIVE</b>To seek for the appropriate concentration, at which IGF-II can exerts its strong effects on postirradiation proliferation, physiological function and differentiation of the rat's osteoblast-like cells (ROB).</p><p><b>METHODS</b>The osteoblast-like cells used were isolated from the calvariae of neonatal (one-day-old) SD rats by sequential enzymatic digestion. The third passages of the cells were irradiated with gamma-ray from a (60)Co source at the doses of 100, 400, 600, and 900 cGy. The medium was changed immediately after irradiation and 5 concentrations of IGF-II, i.e., 0, 0.1, 1.0, 10.0, and 100.0 microgram/L were added. 6 days after radiation (9 days in culture), the examination, or the measurement of relative cell number, was carried out.</p><p><b>RESULTS</b>Radiation inhibited the ROB, even lethally. IGF-II completely counteracted the inhibitory effects when the cells were exposed to the radiation at lower dose (100 cGy), and partially when at higher dose (400 cGy). But after the radiation at much higher dose as 900 cGy, the damages were irreversible, even with the existence of this growth factor.</p><p><b>CONCLUSIONS</b>At least a portion of effective recovery of postirradiation damages may be due to IGF-II-induced radioresistance. Incubation with IGF-II can increase radioresistance or repair of radiation-induced cells damages. However, this effect depends on the dose of radiation.</p>
Subject(s)
Animals , Rats , Cell Division , Radiation Effects , Cells, Cultured , Dose-Response Relationship, Drug , Dose-Response Relationship, Radiation , Insulin-Like Growth Factor II , Pharmacology , Osteoblasts , Physiology , Radiation Effects , Radiation Tolerance , Rats, Sprague-DawleyABSTRACT
Objective To correct bimaxillary protrusion by using b oth orthognathic operation and orthodontic treatment. Methods 46 bimaxillary protrusion patients, 7 male, 39 female, aged from 19 to 31 years (mean 24.2 years), were surgically corrected since 1996. Of them 31 cases underwent preoperative orthodontic treatment. Cephalometric analysis and model s urgery were performed in all patients and 4 kinds of operation methods were used to correct the deformity. All osteotomy segments were fixed with rigid internal fixation. 39 cases underwent postoperative orthodontic treatment. Re sults 34 cases had been followed-up for ranged from 12 to 72 months (mean 27.7months). All osteotomy segments healed well. There were no severe com plications and evident relapse. The maxillary osteotomy segments were moved back for average (6.3?0.9) mm and mandibular osteotomy segments for average (5.2?1 .2) mm. Both occluding relation and facial contour were satisfied. Co nclusion Bimaxillary protrusion can be satisfyingly corrected by usi ng both of orthognathic operation and orthodontic treatment.