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 .

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 evaluate the effects of fixed inclined bite plate on jaw bone and dentition in juveniles with Class Ⅱ division 1 malocclusion.Methods: Eighteen patients(10 male and 8 female aged 11.5～13.8 years old) were treated with fixed inclined bite plate for bite-opening, twelve patients(6 male and 6 female) were involved as the control. Cephalograms were taken before and after the treatment.Results: After treatment ANB was significantly reduced and mandibular development was improved; AFH and PFH were significantly increased; the first molar in mandible was siginificantly elongated.Conclusion: Fixed inclined bite plate is effective in the improvement of sagittal skeletal relationship and in the orthodontic treatment in the juveniles with Class Ⅱ division 1 malocclusion.

0.05). The pressure on the first molar from cheek was higher than that from tongue( P

0.05). Conclusion: The tongue measurement with ultrasonic imaging is reproducible.

Implant anchorage depressed the elongated opposed teeth to prepare enough space for the mandibular dentition.Finally,a better dental implant prosthesis can be achieved.

0.05). At stage 2 to 3, the changes of point A was the greatest. Conclusion: Timing of headgear treatment based on the morphological variation of cervical vertebra can obtain the maximum desirable orthopedic effect.

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 examine the skeletal factors of Angle's classⅡdivision 1 malocclusion in order to find a reasonable treatment protocol. Methods: The skeletal factors were measured and compared between 86 cases aged 12～25 years with AngleⅡ 1 malocclusion and 86 cases at the same age with normal occlusion. Thirteen measurements were chosen on lateral cephalometric radiograph for the comparison. Results: In the group of maloculsion, some measurements standing for sagittal skeletal pattern were statistically defferent from those in the group of normal occlusion, such as decreased SNB angle and SL linear and increased ANB angle, whereas some were not significently different, such as the SNA angle and PNS-ANS linear; some measurements standing for the vertical skeletal pattern were statistically defferent, such as decreased UM-PP linear and LM-MP linear and increased UI-PP linear, whereas some were not significently different, such as LI-PP linear;some measurements standing for growth pattern of mandibular were statistically defferent, such as decreased SN-MP angle. Conclusion: There are posterior alveolar defficency and mandibular retroposition as well as counterclockwise rotation of mandile in the patients with Angle class Ⅱ 1 malocclusion. The treatment for Angle Ⅱ 1 malocclusion should be to make mandibular move forward and downward in accordance with the characteristic skeletal pattern.