1.Precision of three-dimensional printed brackets
Da ZHANG ; Linchuan WANG ; Yanheng ZHOU ; Xiaomo LIU ; Jing LI
Journal of Peking University(Health Sciences) 2017;49(4):704-708
Objective:This study was based on digital orthodontic diagnosis work flow for indirect bonding transfer tray model design and three-dimensional (3D) printing, and the aim of this paper was to inspect the dimensional accuracyof 3D printed brackets, which is the foundation of the follow up work and hoped that will illuminate the clinical application of the digital orthodontics work flow.Methods: The samples which consisted of 14 cases of patients with malocclusion from Department of Orthodontics Peking University were selected, including 8 cases with tooth extraction and 6 cases without tooth extraction.All the 14 patients were taken intra-oral scan (Trios 3Shape,Denmark)and cone-beam computed tomography (CBCT, NewTom 3G volumetric scanner, Aperio Service,Italy)shooting after periodontal treatment.STL data and DICOM data were obtained from intraoral scans and CBCT images.Data segmentation, registration, fusion, automatic tooth arrangement, virtual positioning of orthodontic appliance and conversion the coordinates of malocclusion model were all done with self-programming software.The data of 3D printing model with brackets on it were output finally and printed out with EDEN260V (Objet Geometries, Israel) to make indirect bonding transfer tray.Digital vernier caliper was used to measure the length and width of upper and lower left brackets and buccal tubes on those 3D models after removal of surrounding supporting material by ultrasonic vibration and water-spray.Intra-examiner reliability was assessed by using intra-class correlation coefficients (ICC), and one-sample T test was used to compare the measurements with the standard dimensional data of the brackets.Results: There were significant differences which range in 0.04-0.17 mm between the 13 items out of the 19 measurement items.Except for the length of the lower left premolars''brackets, mean values of the other items were greater than the test value.Conclusion: Although the measurement results in the width of brackets and the width and length of the buccal tubes obtained experimentally were slightly larger than the test value,this may not reduce the accuracy of indirect bonding procedure in clinic necessarily.Whether the differences which range in 0.04-0.17 mm would actually affect the retention and positioning of brackets needs to be confirmed by further studies.
2.Changes of Blood Flow Velocities in Middle Cerebral Artery with Rasmussen Encephalitis: 8 Cases Report
Xiaomo WU ; Xingzhou LIU ; Guang HUANG ; Guoming LUAN ; Shuhua CHEN ; Wei ZHANG
Chinese Journal of Rehabilitation Theory and Practice 2010;16(5):465-467
ObjectiveTo discuss clinical significance of changes in cerebral blood flow velocities with Rasmussen encephalitis. Methods8 cases diagnosed as Rasmussen encephalitis were measured the blood flow velocities in middle cerebral artery (MCA) with transcranial Doppler in ictal and interictal seizures. ResultsIctal mean flow velocity in the ipsilateral MCA to the epileptogenic foci increased 14.02%~48.14% to interictal one, while it was -0.74%~22.63% in the contralateral MCA. ConclusionAn increased flow velocity has been found in the ipsilateral MCA to the epileptogenic foci during seizure in Rasmussen encephalitis patients.
3.Experimental Research on Friction between Domestic Brackets and Archwires
Xiaomo LIU ; Mengqi ZHANG ; Jiuxiang LIN
Journal of China Medical University 2019;48(1):23-28
Objective To study the friction between brackets and archwires and the influential factors. Methods To test the friction of six combinations of canine bracket and stainless steel archwire, and to calculate the critical contact angles for each combination. Results The friction maintains stability with slight changes when the contact angle is smaller than the critical contact angle. The friction increases linearly when the contact angle is larger than the critical contact angle. The friction of different combinations of bracket-archwire are different and the critical contact angles are also different. Conclusion The critical contact angle influences the friction between bracket and archwire significantly. The critical contact angle is relevant to both the structure of the bracket and the size of the archwire.
4.Application of case-based multidisciplinary team teaching mode in clinical practice teaching of gynecology
Yisheng JIAO ; Qingfu ZHANG ; Ningye MA ; Xiaomo LIU ; Dianjun QI ; Yang ZHOU ; Sha NI ; Xue HAN ; Bo LI
Chinese Journal of Medical Education Research 2018;17(5):533-536
Objective To explore the feasibility and evaluate the teaching effect of case-based multidisciplinary team teaching mode in clinical practice teaching of gynecology.Method According to different grade,120 students were divided into experimental group and control group (60 students per group).The teaching content contained three malignant tumor cases,which were cervical cancer,endometrial cancer and ovarian cancer.The course needed 12 periods totally.The experimental group received multidisciplinary team (MDT) teaching mode,and the control group received traditional lecture-based learning teaching mode (LBL).Teaching effect evaluation and test scores would be analyzed at the end of teaching.SPSS19.0 was used for t test and chi-square test.Results Our results showed that the theory test scores,practical skills test scores,the paperwork scores and the total scores of the students in MDT group were significantly higher than those in the traditional group (P<0.05).At the same time,the students' self-evaluation scores in the ability of information retrieval,acquisition,understanding,comprehensive and the ability of self-learning,learning interest,enthusiasm and teamwork were significantly higher than the traditional group (P<0.05).Conclusion MDT teaching mode is feasible,which can improve teaching effect and students' quality,and is worthy of advocating and popularization.
5. A cross-sectional study on economic burden of pulmonary tuberculosis cases from designated tuberculosis hospital
Yan LIU ; Caihong XU ; Zhenyu WANG ; Xiaomo WANG ; Yanhong WANG ; Hui ZHANG ; Li WANG
Chinese Journal of Epidemiology 2019;40(5):559-564
Objective:
To understand the medical expenditure and related household economic burden of pulmonary tuberculosis (TB) patients receiving full course treatment in designated TB hospitals in China and identify the related factors.
Method:
A cross-sectional study was conducted in 535 consecutive TB patients receiving TB treatment from April 2017 to June 2017 in 5 designated TB hospitals in eastern and western China selected through stratified cluster sampling. A questionnaire was used to collect the information about patients’ social economic characteristics and TB diagnosis and treatment expenditure.
Results:
The average total medical expenditure for TB treatment was 12 635.5 yuan (RMB), in which the direct medical expenditure accounted for 65.3% of the total. Nearly half of the total medical expenditure occurred in pre-treatment period. The expenditure in pre- treatment period was higher in the patients with low education level, newly treated patients, and initial sputum negative patients. The median (quartile) for the ratio of total medical expenditure to annual household income was 22%(10%-57%). Ordinal logistic regression analysis showed that low-level education background, lower household income, hospitalization and suffering from other chronic disease might increase the ratio of medical expenditure to annual household income.
Conclusions
Medical expenditure for full course TB treatment is still high in patients in designated TB hospitals. It is suggested to strengthen the capability building of timely found and referral of TB patients in non- designated hospitals and improve fee reduction and exemption policy for some patients.