0.05). Conclusion: The measurements of molar distal movement on model are smilar to those on cephalometric radiograph.

Objective: To evaluate the effect of a new method to treat early primary crossbite . Methods: 20 cases (2.8～6.5 years old ) with anterior crossbite were treated by bonding appliance combined with protracting mask. Cephalometric radiographs were taken and analyzed before and after treatment. Results: On average,in all the 20 cases the maxilla were moved 2.06 mm forward ,mandibular were turned 2.45?downward and backward ,the anterior crossbite was corrected and the face profile was improved satisfactorily.The treatment was conducted for 1.7 months on average. Conclusion: Using bonding appliance combined with protracting mask to treat early primary crossbite can achieve good effects for young children .

0.05) . Conclusion: Mini-implant can replace traditional anchorge composed of extraoral arch and Nance arch in the moving of cuspid distally.

Objective: To evaluate the effects of the modified fixed r everse Twin-block appliance(TBA) combined with maxillary protraction appliance( MPA) in the treatment of early Angle Ⅲ skeletal anterior crossbite. Met hods:TBA combined with MPA was used in 15 growing subjects with early An gle Ⅲskeletal malocclusion (group TBA-MPA). Another 15 subjects with the same type of malocclusion were treated by MPA(group MPA). The effects of treatment we re studied by cephalometric measurments.Results:3-5 months afte r treatment SNB, B-Vert T, Po-Vert T,NPo-FH,Co-Po and 1-NB in group 1 were decreased more than those in group 2 (P0.05).Conclusion:Angle Ⅲ skeletal ante rior crossbite can be corrected successfully with reverse TBA combined with maxi llary protraction appliance by mandible retrusion and maxilla forward growth.

objective: To evaluate the effect of Quad Helix appliance in expanding narrow dental arch. Methods: 12 cases were treated by Quad Helix appliance. The effect was evaluated by measurement of the dental arch. Results: The dental arch of all the patients was expanded in half a year.The width between the maxillary first molars increased by 8.95 mm, and the width between maxillary first premolars increased by 5.7 mm. The average time of expanding was 20.75 weeks, the expanding efficiency was 0.43 mm per week. Conclusion: Quad Helix is an effective orthodontic appliance for correction of narrow dental arch.

Objective: To study the treatment methodology of postoperative disostosis of maxilla in the patients with cleft palate by orthognathia. Methods: 10 cases (6 males and 4 females) of postoperative dysostois of maxilla in the patients with cleft palate were treated by orthognathia. Operation manners and orthodontic treatment were determined by orthodontists and surgeons before treatment. Orthodontic treatment included upper arch expansion, teeth alignment, leveling the Spee's curve etc. Operation on single jaw or double jaw, or extraction of one anterior tooth to decrease lower dlental arch and to coordinate with the upper jaw forward was conducted according to individual situations. Adjustment of intercuspids relation was conducted after operation. Results: In all the 10 cases discrepancy of upper and lower jaws were resolved, profiles of the faces were improved significantly, dental arch symmetry, physiological overjet and overbite were achieved. Conclusion: Orthognathia is effective in the treatment of postoperative dysostosis in the patients with cleft palate.

Objective:To investigate the third molar horizontal and vertical drift automatically after the second molar extraction.Methods: 26 patients,aged 11～18 years old, with the indications of second morlar extraction were divided into two groups:15 cases in experimental group with the extraction of the second molar and 11 in control group without the extraction. A cephalometric radiograph of each patient was traced on before and 9 months after treatment. Vertical and horizontal drift and mesio- angulation of the third molar were measured.Results:The third molar vertical mesio-movement (mm)in experimental and control groups was 7.08?2.04 and 2.09?0.47(P

BACKGROUND: Myogenetic seed cells are the fundamental for construction of tissue-engineered smooth muscle, and optimizing the amplification of seed cells is the key in further clinical application. OBJECTIVE: To analyze the myogenetic potential of rabbit adipose-derived stromal cells induced with the combination of MyoD, transforming growth factor β1 and 5-azacytidine, and to investigate a new way to induce cells. METHODS: The rabbit abdominal fats were isolated and then the adipose-derived stromal cells were separated by col agenase digestion method for myogenetic induction with different methods: 5-azacytidine induction group, MyoD+transforming growth factor β1 induction group, 5-azacytidine+MyoD+transforming growth factor β1 combination induction group. The blank control group was set. The morphological characteristics of cells were observed at 1, 4, 8, 12, 16, 20, 24 and 28 days after induction, and the col agen type Ⅲ level were detected with 4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry and immunohistochemistry. RESULTS AND CONCLUSION: Compared with the other groups, the cel activity was higher in the combination induction group and reached peak at 16 days after induction, the number and volume of myotubes were increased at 20 days with regular arrangement, and desmin showed strong expression. Cel cycle showed the ratio of adipose-derived stromal cells in the DNA replication phase was increased in the combination induction group, the ratio of cells in the clearance period was decreased; the level of col agen type Ⅲ was increased significantly, and the difference was significant. The results indicate that 5-azacytidine combined with multiple factors can promote the differentiation of adipose-derived stromal cells into myoblasts with significant cel proliferation, which is considered as the ideal method to in vitro induction of myoblasts.

Volume concentration determination for atmospheric krypton and xenon is very important for krypton-85 and radioactive xenon isotopes monitoring. An injection setup integrated adjustable quantity sample injection and quantitative dilution function was designed. The effects of EI source parameters on the sensitivity of MS detector were studied. The optimized values were as following: ionization energy of 70 eV, emission current of 40 mA, cathode voltage of 27 mV, focus voltage of 85 mV and lens compensation of 20 V, respectively. A GC-MS method for the determination of krypton and xenon in atmosphere without of sample pretreatment was developed. The minimal detected concentrations for krypton and xenon were 3. 3×10-8(V/V) and 2. 6×10-9(V/V). Moreover, the krypton and xenon concentrations in the ground level air around our laboratory were measured with the results of 1 . 1 × 10-6 ( V/V ) and 9 . 3 × 10-8 ( V/V ) . The related combined standard uncertainties for krypton and xenon results were 2. 38% and 3. 15%, respectively.

Objective To explore the diagnosis and treatment of penile verrucous carcinoma,a distinctive variant of squamous cell carcinoma. Methods The clinical data of 8 patients (mean age,46 years) with penile verrucous carcinoma were analyzed retrospectively.All the tumors showed exophytic,papillary lesions,ranging from 2 to 6 cm in the greatest dimension.The tumors were located at glans in 5 patients and invaded to shafts in the other 3.The diagnosis was established by biopsy of the lesion.Three patients with tumor invading to shafts and 1 patient with large tumor at glans underwent partial penectomy, while the other 4 with the tumors localized at glans were treated by local excision. Results Histopathologic examination of the specimens confirmed tumors-free surgical margins in all the cases.The tumor cells were mostly well-differentiated.Fourteen months postoperatively,local recurrence occurred in 1 patient with local excision and partial penectomy was performed; postoperative follow-up of 9 years showed no recurrence and metastasis. During a follow-up of 4 to 13 years,the other 7 patients were disease-free.The patients with local excision of the tumors reported satisfaction of their sexual lives. Conclusions Verrucous carcinoma of penis is characterized by slow growth and a locally aggressive nature.It seldom develops metastasis to regional lymph nodes or distant areas.The prognosis is favorable after appropriate treatment.