Objective:To establish an animal model in goats for curved mandibular regeneration by distraction osteogenesis(DO).Methods:Four goats were used.Internally installed curved mandibular distractors were activated 6 days after mandibular osteotomy on the mandibular angles or mandibular symphyses at a rate of l mm/d for 25~34 days.The mandibles were examined by roentgenography.Results:The arched defects of the mandibles in the 4 goats were reconstructed by regenerated bone by the end of DO.Conclusion:Internally installed curved distractor may be used for osteogenesis in the repaire of the arched mandibular defects.

Objective: To investigate the distraction osteogenesis technique in correction of severe retro-maxillary deformity following the repair of cleft palate. Methods:10 patients were included in the study. Orthodontic treatment was used as a regular procedure before operation. Distraction osteogenesis technique was used to correct the deformity and malocclusion. 4 of patients applied with the external distractor and others with internal distractor. Latency period was 7 days. Distraction rhythm is 0.8~1 mm/d,2~4 times/d. Consolidation period was 8~12 weeks. Orthognathic surgery was done after distraction finished when necessary. Results:The treatment process was smooth and no severe complication occurred. The maximum of distraction distance is 22 mm, and the minimum of distraction distance was 15 mm. No malunion or ununion occurred in all 10 patients. All the patients were satisfied with the results. Conclusion:Distraction osteogenesis is more suitable for correction of severe retro-maxillary deformity following the repair of cleft palate. Bone transplantation is unnecessary during the operation process with easier handling and lower risk.

Objective To analyse the characteristics of maxillofacial injuries resulted in different causes. Methods A retrospective review was done of patients admitted to the Stomatology Hospital of Fourth Military Medical University from January, 1996 to July, 2003. Data was grouped by different causes. Results 1 188 patients were reviewed, the majority of victims caused by different causes were males, the ratio of male and female is 3.34∶1. Most industrial and sport injury occurred in men. Traffic accidents were the major cause of the midface fracture and mandibular fracture. While violence was the major cause of pure soft injure and alveolar bone fracture. Conclusions Traffic accidents and violence were the major causes of facial injury. The facial injury caused by traffic accidents, industrial accidents and fall was more serious than those caused by other causes. More emphasis should be put on the prevention and treatment of these injuries to minimize the maxillofacial malformation.

BACKGROUND:Rapid prototyping technique has been recently applied in the medical reconstruction and al ows the production of individual implant for patients with tissue defects, achieving an accurate repair.
OBJECTIVE:To repair discontinuous mandibular defects in dogs using rapid prototyped titanium plate in combination with autologous cancellous bone graft.
METHODS:Nine hybrid canines were used, and the skul was scanned using spiral CT. Then CT data were used to construct three-dimensional digital model, in which virtual partial mandibulectomy was performed, and an individualized bone-grafting plate was designed. A titanium plate was manufactured using rapid prototyping and titanium casting. Animal experiment was then performed. A 40-mm discontinuous defect in the right mandibular body was created in the involved dogs. The defect was restored immediately using the customized plate in combination with autologous cancellous iliac blocks. Sequential radionuclide bone imaging, biomechanical testing, three-dimensional microcomputed tomographic scanning, radiology and histological examination were used to evaluate the turnover of the grafts.
RESULTS AND CONCLUSION:A symmetric mandible was reconstructed using the rapid prototyped grafting plate. The grafted bone survived and got corticalized, while a fibrous intermedium was found between the bone graft and the plate. In the reconstruction of mandibular defects, optimal functional and aesthetic outcomes could be achieved using the rapid prototyped grafting plates.

OBJECTIVE：To establish the fingerprint of Bombyx mori and the method for the content determination of multi- components，and to provide reference for comprehensive quality evaluation of B. mori . METHODS ：Using 18 batches of B. mori from different producing areas as samples ，HPLC method was used. The column was Shiseido CAPCELL PAK C 18 AQ S 5 with mobile phase consisted of methanol- 0.05 mol/L potassium dihydrogen phosphate solution （gradient elution ）at the flow rate of 1.0 mL/min. The detection wavelength was 260 nm，and column temperature was set at 30 ℃. The sample size was 10 μL. HPLC fingerprint analysis and similarity evaluation were performed by using TCM Chromatogram Fingerprint Similarity Evaluation System（2012 edition），and the chromatographic peak was identified by comparing with the chromatogram of reference substance. The contents of 4 nucleosides as uracil ，guanine，xanthine，uridine were determined . RESULTS ：A total of 16 common peaks were identified in HPLC fingerprint for 18 batches of B. mori ，and peaks 3，6 ，7 and 8 were identified as uracil ，guanine，xanthine and uridine. The similarity of sample chromatogram with control fingerprint were 0.912-1.000. The linear range of uracil ，guanine， xanthine and uridine were 5.34-534，5.28-528，5.06-506，5.195-519.5 μg/mL（r≥0.999 8）. The limits of detection were 0.032 4， 0.032 0，0.030 7，0.031 2 μg/mL，and the limits of quantitation were 0.106 8，0.105 6，0.101 2，0.103 0 μg/mL. RSDs of precision，reproducibility and stability tests （24 h）were all lower than 1.00％（n＝6）. Average recoveries were 100.15％-102.95％， and RSD s were all lower than 2.00％（n＝9）. The content determination results showed that the content of uracil ，guanine， xanthine and uridine of B. mori from different producing areas were 0.41％-2.46％，0.37％-1.98％，0.72％-2.63％，0.94％-3.67％， respectively. CONCLUSIONS ：Established HPLC fingerprint and content determination method of 4 nucleosides were specific ， accurate and reliable ，which can be used for the quality evaluation and control of B. mori .