Purpose Using quantitative morphometric techniques, To analyzse the developmental characteristics of pulmonary arterial and alveolar with a porcine model of cyanotic congenital heart defect with decreased pulmonary blood flow that we had established. Methods Lung biopsy specimens were taken from animals of control ( C) and cyanosis ( D) groups and than sectioned and stained. The morphological observation and the method of half-quantitative morphometric technique were applied to measure the following char-acteristics:the media thickness ( MT) and the percentage of media thickness ( MT%) , the media section area ( MS%) and the per-centage of media section area ( MS) , the numbers of micro-arteries per square centimeter ( APSC) . In addition, we calculated the ratio of CMA, PMA and NMA in the same section of lung biopsy specimens. Results There showed universally distended, irregular and thin-walled vessels in the lung biopsy specimens of group D under the light microscope. There was an increased number of pulmonary arteries whose media were hypoplastic. The MT, MT% and MS, MS% in group D were significantly less than those of group C ( all P<0. 001), the APSC was also less in group D than in group C (P<0. 01), but MAN were not significantly different between two groups (P>0. 05). Electron microscopy revealed endothelial swell and irregularity, a thinned basement membrane, a disorganized or disrupted elastic fibers layer. The smooth muscle of vascular media shrunk. In addition to these, other changes included the mitochon-drion vacuolization, a diminished cellular organelle and type Ⅱ alveolar epithelial hyperplasia. Conclusion The pulmonary vessels are evidently hypoplastic or degenerated in cyanotic congenital heart defect with decreased pulmonary blood flow, and the function is thought to be influenced by the morphological changes. To promote the pulmonary artery growth and improve this pathophysiological state, it is critical to increase the pulmonary blood flow.

BACKGROUND: In clinic,the mechanical study about fibula reconstruction for the repair of mandibular bone defect is unrealistic; the finite element analysis, however, provides a new approach for the biomechanical study of mandibular reconstruction. OBJECTIVE: To establish the three-dimensional finite element model of mandibular body defect under fibula reconstruction and smal titanium plate fixation, and to analyze the biomechanical features. METHODS:The three-dimensional model of mandibular body defect under fibula reconstruction and internal fixation was established. 100 N bite force was loaded on the anterior teeth, contralateral first molar and contralateral second molar, respectively. The maximum stress and maximum displacement before and after model reconstruction, the stress of bone tissues around the titanium plate and titanium screw holes under anterior and posterior loading, and the maximum displacement of the front and rear ends of the fibula under anterior and posterior loading were observed. RESULTS AND CONCLUSION:The maximum stress of the normal mandible concentrated in the condylar neck. In the reconstructed models, the maximum stress concentrated in the contralateral condylar neck. Under the same bite force, the maximum stress value of the reconstructed mandibular model was greater than that of the normal mandible. The maximum stress value of the anterior teeth was greater than that of the posterior teeth. The stress value was maximal between two screw holes inside each titanium plate and almost concentrated in the mandibular angle. The maximum stress of the residual titanium screw of the mandible concentrated in the first titanium screw over the mandibular defect under loading, while the maximum stress of the titanium screw of the fibular end concentrated in the titanium screw below the mesial segment of the fibula. The cortical bone around the screw holes located at the residual end of the mandible near the defect area and the upper plate of the mesial segment of the fibula was the maximum stress concentrated site, and the maximum stress of anterior tooth loading was greater than that of the posterior tooth loading. The displacement values of the fibula gradualy reduced from the upper edge to the lower edge in the X-axis, from the anterior and posterior ends to the middle part in the Y-axis, as wel as from the anterior end to the posterior end in the Z-axis. The maximum displacement values of the anterior and posterior ends of the fibula were at the Z-axis and Y-axis, respectively. The maximum displacement value under anterior tooth loading was greater than that under posterior tooth loading. These results show that the titanium plate over the mandibular angle that is most easy to break should be reinforced. If the stress of titanium screw tip and neck is relatively large, double cortical titanium screw is preferred; if the stress of titanium screw and titanium plate at the fibula end and residual end of the mandible is relatively large, we should pay attention to their stability and fixation; if the stress of anterior tooth occlusion is greater than that of posterior tooth occlusion, anterior tooth occlusion should be avoided after repair.

OBJECTIVETo investigate the correlative factors influencing the stability of orthodontic treatment out of retention.

METHODSPre-treatment, post-treatment and 2 approximately 8 years out of retention study models of 74 cases with malocclusion were assessed by the PAR (Peer Assessment Rating) index.

RESULTS(1) Out of retention, the relapse rate was 13.01% in weighted PAR total scores and the relapse rate was 6.38%, 15.56%, 28.86%, 22.41% in alignment, overjet, overbite and transverse buccal occlusion respectively. (2) The rate of great improvement was decreased from 77.03% after treatment to 64.86% out of retention. The PAR score increased in 53 cases (71.62%), unchanged in 6 cases (8.11%) and reduced in 15 cases (20.27%) out of retention. (3) The weighted total scores in the Begg appliance were higher than that in Edgewise out of retention (P < 0.05). (4) The alignment and PAR total scores out of retention were higher in class II malocclusion than in class I malocclusion (P < 0.05). (5) The weighted PAR total scores post-retention were higher in unilateral extraction than in other groups (P < 0.01).

CONCLUSIONS(1) There was a trend that teeth relapsed to original position out of retention. The relapse rate was greater in alignment, overjet, overbite and transverse buccal occlusion. (2) The stability out of retention was not related to patient's age and sex, but was related to the types of appliance, malocclusion and extraction.

Adolescent ; Adult ; Age Factors ; Child ; Female ; Follow-Up Studies ; Humans ; Male ; Malocclusion ; pathology ; therapy ; Orthodontics, Corrective ; methods ; Recurrence ; Sex Factors ; Time Factors ; Treatment Outcome

Objective To observe the therapeutic effect of Guanxin Prescription No.1 (GP1)for coronary heart disease (CHD)and its influence on homocysteine (Hcy).Methods Sixty CHD patients were equally randomized into two groups.Both of the two groups received routine western medicine,and the treatment group additionally received GP1 (mainly composed of Radix Codonopsis,Radix Ophiopogonis,Fructus Schisandrae Chinensis,Rhizoma Polygonati Odorati,Rhizoma Chuanxiong,Rhizoma Anemarrhenae,Radix Salviae Miltiorrhizae,Radix Notoginseng,Radix Curcumae,etc).Four weeks constituted one treatment course.The total therapeutic effect and the effect on angina pectoris (AP)and electrocardiogram (ECG)were evaluated after treatment.Meanwhile,the changes of blood lipid levels,serum Hcy and internal-middle thickness (IMT)of carotid artery were observed.Results The total therapeutic effect and the effect on AP and ECG in the treatment group were superior to those in the control group (P0.05 compared with those before treatment).The decrease of serum Hcy level was obvious in the treatment group than that in the control group (P

BACKGROUND:Three-dimensional finite element has been widely used in the oral cavity field, but little is reported on the three-dimensional finite element reconstruction of the mandibular body using titanium plate. OBJECTIVE:To study the biomechanical characteristics of reconstructing the mandibular body using titanium plate. METHODS:We established a three-dimensional finite element model of mandibular body defect undergoing reconstruction using bicortical titanium screws and titanium plate. Under the simulated normal occlusion state, a 200 N vertical load was added to the central fossa of the occlusal surface of the right mandible first molar. Then, stress distribution and maximum displacement of the mandible, titanium screw, and titanium plate were analyzed. RESULTS AND CONCLUSION:Under the simulated normal occlusion state, mandible stress was concentrated in the mandibular body and mandibular branch, especial y in the anterior and posterior edges of the mandibular branch and the lower edge of the mandible. The stress in the posterior edge of the mandible was lower than that in the anterior edge of the mandible, and moreover, the contact site between the titanium plate and the mandible also presented a concentration of stress. The maximum stress of the bicortical titanium screws appeared near the screw cap, and the stress was also concentrated at the contact site between the titanium screw and the titanium plate. The maximum stress of the titanium screw at the ascending branch of the mandible was higher than that of the titanium screw at the anterior end of the defect. For the titanium plate, the stress was mainly concentrated at the fixed site of the titanium screws;the peak stress of the anterior and posterior edges of the titanium plate was found at the contact site between the anterior end of mandibular defect and the titanium stress as wel as between the ascending branch of the mandible and the titanium screw. After mandibular body reconstruction using the titanium plate, a displacement was likely to occur at the contact site between the anterior end of mandibular defect and the titanium plate. In conclusion, these findings indicate that mandibular body reconstruction using bicortical titanium screws and titanium plate is relatively stable, but the titanium plate fixed at the anterior part of the mandibular angle is prone to breakage.

Objective:To analyze the risk factors for postoperative pulmonary venous obstruction after correction of total anomalous pulmonary venous connection(TAPVC).Methods:We retrospectively reviewed all patients undergoing operative repair of TAPVC in our institution from December 2013 to January 2018. Patients with functionally univentricular circulations or atrial isomerism were excluded. Patients were divided into two groups according to whether there was pulmonary vein obstruction. The clinical variables of the two groups were compared. Variables for the multivariable analysis were chosen if there was statistical significance on univariable analysis.Results:145 patients were included, 91(63%) males, aged 4(2, 8)months and weight 5.5(4.5, 7.5)kg. Mean follow-up interval was(51±23) months. Postoperative obstruction developed in 27 patients(18.6%). The differences of anatomic type[supracardiac 18(67%) vs.59(50%), cardiac 4(15%) vs. 50(42%), infracardiac 3(11%) vs. 1(1%), mixed 2(7%) vs. 8(7%), P=0.003], preoperative obstruction[yes 19(70%) vs. 37(31%), no 8(30%) vs. 81(69%), P<0.001], associated cardiac lesions[yes 13(48%) vs. 27(23%), no 14(52%) vs. 91(77%), P=0.008] and bypass time[109(89, 129)min vs. 88(70, 110)min, P=0.002] between two groups were statistical significant. A multivariable model showed preoperative obstruction( P<0.001) and bypass time( P=0.009) were associated with postoperative obstruction. Conclusion:The incidence of pulmonary vein obstruction after correction of TAPVC was still high. If there was preoperative obstruction, or the bypass time was too long during operation, the surveillance of pulmonary vein obstruction should be strengthened after operation.