1.A 10 years retrospective study of the projects supported by the ministry of national science and technology in oral medicine
Yijiao ZHAO ; Huifang YANG ; Yong WANG
Chinese Journal of Medical Science Research Management 2016;29(3):192-195,205
Objective To investigate the projects funded by ministry of national science and technology (NSTP) in China allocated to oral medicine from 2003 to 2013.Methods The data regarding the NSTP allocated to oral medicine research from 2003 to 2013 were collected,including funding years,the expenses and numbers of programs,the secondary discipline of oral medicine and the program units,etc.Multidimensional analyses were provided subsequently.Results From 2003 to 2013,a total number of 59 projects and 210 million CNY supported by NSTP were allocated to oral medicineresearch.The development trend showed increased year by year.The oral medicine researches were allocated by almost all major types of NSTP and the funding directions were tending to diversified development.But,the projects units were relatively concentrated in clinical,teaching and research institutions,only few enterprises.Conclusions Over the past 10 years,the sustainable improvement of NSTP in oral medicine research has led to the development of oral medicine discipline.NSTP has becoming an important way for oral medicine research to obtain State-level funding.
2.Retrieval strategy for dentistry literatures based on medical subject headings
Yijiao ZHAO ; Yong WANG ; Peijun LV ; Chengmei REN
Chinese Journal of Medical Science Research Management 2010;23(5):334-336
Objective To investigate a retrieval strategy for dentistry literature based on medical subject headings (MeSH). Methods We analysed the MeSH Tree Structures of PubMed in 2009 and combined it with the core glossary of dentistry to find out highly frequent dental words in MeSH. Then 6 words were singled out from the whole MeSh Tree to apply for a retrieval strategy for dentistry literatures. Results 102,500 pieces of dentistry literature were obtained from the year 2006 to 2008. Conclusions This research strategy can improve the efficiency of literature search in dentistry field for clinical or laboratory researches.
3.Comparison of two kinds of methods evaluating the degree of facial asymmetry by three-dimensional data
Yuxue XIONG ; Huifang YANG ; Yijiao ZHAO ; Yong WANG
Journal of Peking University(Health Sciences) 2015;(2):340-343
Objective:To compare two digital methods of quantitatively accessing the degree of facial asymmetry by three-dimensional data.Methods: The three-dimensional data of 20 subjects were got by the FaceScan, and then were input to the reverse engineering software Imageware 13.0 and Geomagic 12 .Their mirror data were acquired and superimposed with the original data by the methods of interactive closest points ( ICP) and Procrustes analysis ( PA) .The mid-sagittal planes of the two methods were ex-tracted respectively, the degree of facial asymmetry and the distance of 21 automatic landmarks to mid-sagittal plane were calculated and compared.Results:The paired t test was taken and t=1.346, P=0.193.Conclusion:We can safely come to the conclusions that for the subjects with no evident facial asymmetry, there are no significant difference between the PA and the ICP methods for extracting the mid-sagittal plane from three-dimensional data.
4.A cone-beam computed tomography study on crown-root morphology of maxillary anterior teeth in Class Ⅱ,division 2 malocclusion
Min LI ; Siwei WANG ; Yijiao ZHAO ; Yi LIU
Journal of Peking University(Health Sciences) 2016;48(1):105-110
Objective:To study crown-root morphology of maxillary anterior teeth in ClassⅡ,division 2 malocclusion using cone-beam CT (CBCT)combined with computer aided measurement technology to provide guidance for clinical treatment.Methods:The samples which consisted of 36 cases radiographed with CBCT techniques were selected and divided into two groups (1 8 each )based on the type of maloc-clusion presented:ClassⅡ,division 2 group (groupⅡ2)and ClassⅠgroup (groupⅠ).The measure-ments of crown-root morphology including crown-root angle and surface-shaft angle were got by Multiple Planer Reconstruction of CBCT data uploaded into InvivoDental software 5.0.The data were processed with SPSS 20.0 software package and t test was employed for comparison of angular measurements. Results:In group Ⅰ,crown-root angles of maxillary central incisor,maxillary lateral incisor and maxillary canines were 1 79.08°±3.31 °,1 76.55°±2.77°and 1 84.20°±2.51 °respectively, surface-shaft angles were 21 .00°±2.63°,1 9.63°±2.35°and 1 9.36°±2.30°respectively. While in group Ⅱ 2 ,crown-root angles of maxillary central incisor,maxillary lateral incisor and maxillary canines were 1 76.80°±2.62°,1 74.1 3°±3.28°and 1 81 .79°±2.88°respectively, surface-shaft angles were 23.20°±2.95°,22.29°±2.1 9°and 20.61 °±2.34°respectively. Compared with group Ⅰ,significant statistical differences were observed with the exception of sur-face-shaft angle of maxillary incisor.There was significant difference in crown-root angle between group Ⅱ2 and 1 80 °.Conclusion:The maxillary anterior teeth in ClassⅡ,division 2 malocclusion exhibited significant crown-root morphology which would influence the torque after orthodontic treat-ment.Special attention should be paid to the position of maxillary anterior teeth roots during ortho-dontic treatment for Class Ⅱ,division 2 malocclusion.The ideal position of tooth movement should be decided by the root rather than the location of the crowns.
5.Three-dimensional data fusion method for tooth crown and root based on curvature continuity algorithm
Yijiao ZHAO ; Yi LIU ; Yuchun SUN ; Yong WANG
Journal of Peking University(Health Sciences) 2017;49(4):719-723
Objective:To explore a three-dimensional (3D) data fusion and integration method of optical scanning tooth crowns and cone beam CT (CBCT) reconstructing tooth roots for their natural transition in the 3D profile.Methods: One mild dental crowding case was chosen from orthodontics clinics with full denture.The CBCT data were acquired to reconstruct the dental model with tooth roots by Mimics 17.0 medical imaging software, and the optical impression was taken to obtain the dentition mo-del with high precision physiological contour of crowns by Smart Optics dental scanner.The two models were doing 3D registration based on their common part of the crowns'' shape in Geomagic Studio 2012 reverse engineering software.The model coordinate system was established by defining the occlusal plane.crown-gingiva boundary was extracted from optical scanning model manually, then crown-root boundary was generated by offsetting and projecting crown-gingiva boundary to the root model.After trimming the crown and root models, the 3D fusion model with physiological contour crown and nature root was formed by curvature continuity filling algorithm finally.In the study, 10 patients with dentition mild crowded from the oral clinics were followed up with this method to obtain 3D crown and root fusion models, and 10 high qualification doctors were invited to do subjective evaluation of these fusion models.Results: This study based on commercial software platform, preliminarily realized the 3D data fusion and integration method of optical scanning tooth crowns and CBCT tooth roots with a curvature continuous shape transition.The 10 patients'' 3D crown and root fusion models were constructed successfully by the method, and the average score of the doctors'' subjective evaluation for these 10 models was 8.6 points (0-10 points).which meant that all the fusion models could basically meet the need of the oral clinics, and also showed the method in our study was feasible and efficient in orthodontics study and clinics.Conclusion: The method of this study for 3D crown and root data fusion could obtain an integrate tooth or dental model more close to the nature shape.CBCT model calibration may probably improve the precision of the fusion model.The adaptation of this method for severe dentition crowding and micromaxillary deformity needs further research.
6.A scanning method for the dental casts of intercuspal position
Yong WANG ; Yijiao ZHAO ; Peijun LV ; Zhongke LI
Journal of Peking University(Health Sciences) 2004;0(03):-
Objective: To acquire the 3D point-cloud of the dental casts of intercuspal position and rebuild it in computer. Methods:Aspecial scanning method was used to acquire the point-cloud of dental cast by using the D.02-L-3D SCANNER and rebuild the model by computer. Results: The method could acquire a 3D model with high resolving power and clear-cut dental anatomic configuration for the dental casts of intercuspal position. Conclusion: This is a viable method of scanning with many advantages, such as precision, simplicity , high efficiency. It could satisfy the requirements of clinical practice, teaching and scientific research.
8.Constructing 3-dimensional colorized digital dental model assisted by digital photogra-phy
Hongqiang YE ; Yushu LIU ; Yunsong LIU ; Jing NING ; Yijiao ZHAO ; Yongsheng ZHOU
Journal of Peking University(Health Sciences) 2016;48(1):138-142
Objective:To explore a method of constructing universal 3-dimensional (3D)colorized digital dental model which can be displayed and edited in common 3 D software (such as Geomagic se-ries),in order to improve the visual effect of digital dental model in 3D software.Methods:The mor-phological data of teeth and gingivae were obtained by intra-oral scanning system (3Shape TRIOS),con-structing 3D digital dental models.The 3D digital dental models were exported as STL files.Meanwhile, referring to the accredited photography guide of American Academy of Cosmetic Dentistry (AACD),five selected digital photographs of patients’teeth and gingivae were taken by digital single lens reflex camera (DSLR) with the same exposure parameters (except occlusal views ) to capture the color data.In Geomagic Studio 201 3,after STL file of 3D digital dental model being imported,digital photographs were projected on 3D digital dental model with corresponding position and angle.The junctions of different photos were carefully trimmed to get continuous and natural color transitions.Then the 3 D colorized digital dental model was constructed,which was exported as OBJ file or WRP file which was a special file for software of Geomagic series.For the purpose of evaluating the visual effect of the 3 D colorized digital model,a rating scale on color simulation effect in views of patients’evaluation was used.Sixteen patients were recruited and their scores on colored and non-colored digital dental models were recorded.The data were analyzed using McNemar-Bowker test in SPSS 20.Results:Universal 3D colorized digital dental model with better color simulation was constructed based on intra-oral scanning and digital photography. For clinical application,the 3D colorized digital dental models,combined with 3D face images,were in-troduced into 3D smile design of aesthetic rehabilitation,which could improve the patients’cognition for the esthetic digital design and virtual prosthetic effect.Conclusion:Universal 3 D colorized digital dental model with better color simulation can be constructed assisted by 3 D dental scanning system and digital photography.In clinical practice,the communication between dentist and patients could be improved as-sisted by the better visual perception since the colorized 3 D digital dental models with better color simula-tion effect.
9.Quantitative evaluation of the measurement accuracy of 2 three-dimensional facial scanners
Yijiao ZHAO ; Yuxue XIONG ; Huifang YANG ; Peijun LV ; Yuchun SUN ; Yong WANG
Journal of Practical Stomatology 2016;32(1):37-42
Objective:To evaluate the actual measurement accuracy of 2 three-dimensional(3D)facial scanners for real person. Methods:3D digital face models of 1 0 volunteers with normal ficial form were obtained by 3dMD and FaceScan facial scanners respec-tively.The measurement values of 1 0 feature lengths and 5 feature angles were measured on each 3D model by the software respective-ly.The reference values of all characteristics were acquired by line laser scanner (Faro)with high accuracy.Statistical and surveying analysis were taken between the measurement values and reference values.Facial morphology measurement error and actual accuracy of facial scanners were obtained finally.Data were statistically analysed.Results:The length measurement accuracy of 3dMD and FaceS-can was(-0.37 ±0.68)mm and (-0.29 ±0.53)mm(P =0.223),the angle measurement accuracy was (-0.22 ±2.1 4)°and (0.1 2 ±2.69)°(P =0.428),respectively.Conclusion:The 3D data of ficial morphology obtained by the 2 scanners are not signifi-cantly different.
10.Evaluation of three methods for constructing craniofacial mid-sagittal plane based on the cone beam computed tomography
Siwei WANG ; Min LI ; Huifang YANG ; Yijiao ZHAO ; Yong WANG ; Yi LIU
Journal of Peking University(Health Sciences) 2016;48(2):330-335
Objective:To compare the accuracyof interactive closet point (ICP)algorithm,Procrustes analysis (PA)algorithm,andalandmark-independent method to construct the mid-sagittal plane (MSP)of the cone beam computed tomography.To provide theoretical basis for establishing coordinate systemof CBCT images and symmetric analysis.Methods:Ten patients were selected and scanned by CBCT before orthodontic treatment.The scan data was imported into Mimics 10.0 to reconstructthree dimensional skulls.And the MSP of each skull was generated by ICP algorithm,PA algorithm and landmark-independ-ent method.MSP extracted by ICP algorithm or PA algorithm involvedthree steps.First,the 3D skull processing was performed by reverse engineering software geomagic studio 2012 to obtain the mirror skull. Then,the original and its mirror skull was registered separately by ICP algorithm in geomagic studio 2012 and PA algorithm in NX Imageware 1 1 .0.Finally,the registered data were united into new data to calcu-late the MSP of the originaldata in geomagic studio 2012.The mid-sagittal plane was determined by SEL-LA (S),nasion (N),basion (Ba)as traditional landmark-dependent methodconducted in software InVivoDental 5.0.The distance from 9 pairs of symmetric anatomical marked points to three sagittal plane were measured and calculated to compare the differences of the absolute value.The one-way ANOVA test was used to analyze the variable differences among the 3 MSPs.The pairwise comparison was performed with LSD method.Results:MSPs calculated by the three methods were available for clinic analysis,which could be concluded from the front view.However,there was significant differences among the distances from the 9 pairs of symmetric anatomical marked points to the MSPs (F=10.932,P=0.001).LSD test showed there was no significant difference between the ICP algorithm and landmark-independent method (P=0.1 1 ),while there was significant difference between the PA algorithm and landmark-independent methods (P =0.01 ).Conclusion:Mid-sagittal plane of 3D skulls could be generated base on ICP algorithm or PA algorithm.There was no significant difference between the ICP algorithm and landmark-independent method.For the subjects with no evident asymmetry,ICP algorithm is feasible in clinical analysis.