Objective : To discuss the effectiveness and mechanism for movement of maxillary buccally transposed canines by using a door-shaped individualized dental archwire mechanic and to provide a reference for clinicians. Methods: Eight patients with unilateral maxillary transposed canines were enrolled. All patients were treated with door-shaped individualized archwires. Before treatment (T1) and after the crowns of the transposed canines were moved to the right buccal positions in the dental arch during the treatment (T2), orthopantomograms were taken both at T1 and T2 to compare the linear changes (distance changes of the crown and root apex) and angular changes to study the mechanisms of tooth movement. The probing depth and buccal crown height were measured using a periodontal probe to compare periodontal changes before treatment (T1) and after treatment (T3) between the transposed canines and contralateral canines. Results: All eight transposed canines were successfully brought back to their normal dental arch position but were made more buccal by using the door-shaped individualized dental archwire, with a mean of (11.5 ± 2.7) months. The average overall duration was (28.3 ± 4.7) months. The crown distance changes of the canines from T1 to T2 (8.1 mm) were greater than those of the root apexes (1.5 mm) (P<0.05). The mean angulation changes of the long axes of the canines were 17.5°. There was no significant difference in the depth of periodontal measurement and buccal crown height measurement between T1 and T3 (P>0.05). Conclusion The buccal movement of maxillary transposed canines under a door-shaped individualized dental archwire was effective and feasible. The movement pattern under this mechanism was controlled tipping.

OBJECTIVE To establish the characteristic chromatogram of Chaenomeles sinensis， determine the contents of rutin， hyperin and quercitrin， and to identify C. sinensis and C. speciosa. METHODS HPLC method was performed on Agilent 5 TC-C18 column， with acetonitrile-0.2% formic acid solution as the mobile phase for gradient elution， at the flow rate of 1.0 mL/min. The column temperature was 30 ℃ . The detection wavelength was 330 nm in characteristic chromatogram and 350 nm in content determination. The characteristic chromatogram of C. sinensis was established and similarity was evaluated by the Similarity Evaluation System for Chromatographic Fingerprint of TCM （2012 edition）. Hierarchical cluster analysis of 15 batches of C. sinensis （S1-S15） was performed by using SPSS 23.0 software. The contents of 3 flavones in 15 batches of C. sinensis and 7 batches of C. speciosa （S16-S22） were determined， while their characteristic chromatograms were compared. RESULTS The similarities of the characteristic chromatogram for 15 batches of C. sinensis ranged from 0.783 to 0.969， and 11 characteristic peaks were confirmed. Four constituents were identified as chlorogenic acid， rutin， hyperin and quercitrin. The medicinal materials in 15 batches of C. sinensis could be divided into 2 categories： S5-S8 were one category， and the others belonged to one category. The characteristic chromatogram of C. sinensis was obviously different from C. speciosa. The contents of rutin， hyperin and quercitrin in 15 batches of C. sinensis were 48.99-294.45， 3.49-102.55， 31.98-149.49 μg/g， respectively. The content of rutin in C. speciosa was lower than that in C. sinensis. None of hyperin （except for S20） and quercitrin were detected in C. speciosa. CONCLUSIONS The characteristic chromatogram and the method for content determination of 3 flavones in C. sinensis are established successfully and can be used for the quality control of C. sinensis and its identification from C. speciosa.