ABSTRACT
Objective: To evaluate the biomechanical effects of combined use of miniscrew and clear aligner in different kinds of loading condition on the en-mass retraction of maxillary anterior teeth. Methods: 3 D finite element models of the maxillary bone with miniscrews and clear aligner were reconstructed using the method of reverse engineering with CBCT data of an adult patient who had maxillary first premolars extracted. The orthodontic force was loaded by (1) clear aligner, (2) clear aligner and 1. 47 N force of retraction at appliance and (3) clear aligner and 1. 47 N force of retraction at canine, respectively. Results: Under the working condition of (1), (2) and (3), in sagittal direction, the displacement difference of crown and root of the maxillary central incisor was 1. 12 E-02 mm, 1. 29 E-02 mm and 9. 62 E-03 mm respectively, the displacement of the first molar crown was-2. 49 E-02 mm, -2. 09 E-02 mm and-2. 00 E-02 mm respectively; in vertical direction, extrusion of the maxillary central incisor was 1. 77 E-03 mm, 2. 93 E-03 mm and 6. 53 E-04 mm respectively. Conclusion: The working condition (3) is more advantageous to control the torque of incisors and to save the anchorage of posterior teeth, and more effective to control the extrusion of the incisors.
ABSTRACT
Objective To establish the quality control methods for Qihuang Fuzheng particle .Methods Astragali Ra-dix ,Rehmanniae Radix Praeparata ,Corni Fructus ,Chuanxiong Rhizoma ,Angelicae Sinensis Radix , Paeoniae Radix Rubra ,Moutan Cortex ,and Ophiopogonis Radix were identified with TLC .HPLC method was used for loganin assay in Cor-ni Fructus .Results TLC identification methods for the main components were established .The TLC spots were clear with good separation .No interference was detected from the negative samples .The peak response and concentration of loganin showed good linear relationship over the range of 4 .02-80 .40 μg/ml (r=0 .9999) .The mean recovery of loganin was 99 .02％(RSD=0 .64％ ,n=9) .Conclusion The established quality control methods are accurate ,reliable ,and specific ,which lay a foundation for the quality control of Qihuang Fuzheng particle .
ABSTRACT
Objective:To establish the quality control methods for Qianliedan particle. Methods:TLC was used to identify Scutel-lariae Barbatae Herba, Astragali Radix, Glycyrrhizae Radix Et, Rhizoma Praeparata Cum Melle, Psoraleae Fructus and Curcumae lon-gae Rhizoma. The content determination item was developed by determining the content of scutellarin in Scutellariae Barbatae Herba by HPLC. Results:The TLC spots were clear and well-separated without any interference from the negative sample. A good linear rela-tionship was established between the peak response and the concentration of scutellarin within the range of 3. 96-79. 20 μg·ml-1(r=0. 999 9). The mean recovery of scutellarin was 99. 34% (RSD=1. 25%, n=9). Conclusion:The established quality control meth-ods are accurate, reliable, stable and specific, which can be well used for the quality control of Qianliedan particle.