1.A study of measurement of facial skin color using digital camera
Journal of Practical Stomatology 2009;25(6):858-861
Objective; To evaluate the reliability and reasonability of maxillofacial skin color match using the digital camera. Methods; The stability of the experimental light source was evaluated before establishing the color measurement. 122 volunteers aged from 22 to 32 years were recorded by a Canon EOS 20D digital camera in studio environment when the light source was stable. Photographs were taken under a set exposure parameters(f/4.5,1/25 s,custom white balance,ISO 800) and saved as JPEG format. The CIE L~* a~* b~* color values were obtained from the digital images using Adobe Photoshop7.0 after color correction. All data were analyzed using SPSS 10. 0. Results;The experimental light source was stable in 21 to 70 minutes. It was suitable for color measurement during this period. The color parameters of all tested maxillofacial skin were:L~*49~66,a~*7 - 18,b~*5 -22. Conclusion;The assessment of maxillofacial skin color depend on method of measurement and instrument. The method of maxillofacial skin color matching by digital camera seems reliable.
2.Tensile property and hardness of SY-1 and MDX4-4210 silicon rubber
Longquan SHAO ; Yimin ZHAO ; Xinyi ZHAO
Journal of Practical Stomatology 1996;0(02):-
0.05).The elongation at break of SY-1 was stronger than that of MDX4-4210 (P
3.The effect of roughness on adhesive properties of polymethyl methacrylate and SY-1 silicone elastomer
Le QU ; Yimin ZHAO ; Xinyi ZHAO
Journal of Practical Stomatology 2001;0(03):-
Objective: To evaluate the effect of roughness on adhesive properties of polymethyl methacrylate and SY-1 silicone elastomer.Methods:5 specimens of polymethyl methacrylate were polished by sand paper of different standards and the roughness of polymethyl methacrylate surfaces were measured by roughmeter. The tension strength between polymethyl methacrylate with different degrees of roughness and SY-1 silicone elastomer were tested according to national standards. Results: After the surfaces of polymethyl methacrylate were respectively polished by sand paper of the standard 160,320 and 800, the sufrace roughness decreased, but the tension strength between polymethy1 and SY-1 silicone elastomer was increased(P
4.The progress and prospect of stomatology
Yimin ZHAO ; Jihua CHEN ; Liang KONG
Medical Journal of Chinese People's Liberation Army 2001;0(08):-
Objective To summarize the progresses made domestically and abroad and the developmental tendency of stomatology,and to propose the orientation of development in stomatology in China. Methods The latest progresses and developmental tendency in the field of stomatology were achieved by investigating related references,reviews,research reports and treatises published in recent 10 years. Results In recent years,the increasing integration of stomatology,comprehensive medicine,biomedical engineering,and tissue engineering facilitated the development of stomatology towards digitization,minimal invasion,functionalization and customization,which has made great achievements in basic researches and clinical techniques of stomatology in the armed forces. Conclusions It is the key period of the Twelfth Five-Year Plan for the development of the stomatology in the armed forces. Servicing the basic level of the troop,promoting dominant subjects,improving weak components of the discipline,and comprehensively promoting the internationalization should be insisted in driving innovations of stomatology in the armed forces.
5.Neural stem cell transplantation effects on neuronal apoptosis, differentiation and neurobehavior changes in rats with cerebral ischemia
Yimin LIU ; Yanyan ZHAO ; Hongbing CHEN
Chinese Journal of Tissue Engineering Research 2017;21(13):2029-2035
BACKGROUND:In recent years, neural stem cell transplantation has become a research hotspot in the treatment of brain injuries, such as cerebral ischemia, but the mechanism has not been fully elucidated.OBJECTIVE:To study the effect of neural stem cell transplantation on neuronal apoptosis and differentiation and neurobehaviors in cerebral ischemia rats.METHODS:Ninety Sprague-Dawley rats with cerebral ischemia were randomized into model group, phosphate buffer solution (PBS) group and neural stem cell group (n=30 per group). Another 30 rats were selected as sham operation group with vascular exposure but with no occlusion under anesthesia. Thirty normal 30 rats acted as controls with no treatment. Thereafter, neurological deficit scores, cerebral infarction volume, the number of apoptotic nerve cells,BrdU/NeuN and BrdU/GFAP expression were detected at 3, 7, 14 days after modeling.RESULTS AND CONCLUSION:On the 7th day and 14th day after modeling, the neurological deficit scores, cerebral infarct volume and the number of apoptotic nerve cells in the neural stem cell group were significantly lower than those in the model group and PBS group (P < 0.05), but there was no statistically significant difference between the model group and PBS group (P > 0.05). On the 3rd day, 7th day and 14th day after modeling, the neurological deficit scores and the number of apoptotic nerve cells in the control group and sham operation group were significantly lower than those in the model group, PBS group and neural stem cell group (P < 0.05). On the 3rd day after modeling, the BrdU/NeuN positive cell count in the model, PBS and neural stem cell groups showed no statistically significant differences (P > 0.05); on the 7th day and 14th day after modeling, the BrdU/NeuN positive cell count in the neural stem cell group was significantly higher than that in the model group and PBS group (P < 0.05), but the difference between the model group and PBS group was not statistically significant (P > 0.05). On the 3rd day, 7th day and 14th day after modeling, BrdU/GFAP positive cell count in the neural stem cell group was significantly lower than that in the model group and PBS group (P < 0.05),and the latter two groups had no statistically significant difference (P > 0.05). In summary, neural stem cell transplantation for cerebral ischemia contributes to the neuronal differentiation of endogenous neural stem cells in the subventricular zone of the lateral ventricles, reduce neuronal apoptosis, and ease ischemic damage to the rat neurological function.
6.Application Features of Field Digital Oral Medical Vehicles
Gang LI ; Yimin ZHAO ; Min HU
Chinese Medical Equipment Journal 2004;0(08):-
Objective To test the performance of the field digital oral medical vehicles(two chairs) developed by School of Stomatology,the Fourth Military Medical University.Methods The field digital oral medical vehicle was developed by using dental health care system,diagnostic imaging systems,oral endoscopic systems,infection control systems,digital management system,the sewage treatment system,temperature conditioning systems,power generation systems,automotive GPS positioning system and other systems.Results The vehicle was characteristized by reliable performance,high degree of functional serialization,complete medical facilities and good operability of the internal layout.Conclusion Its functions fully meet the requirements in field oral disease prevention and control as well as first aid.
7.Three-dimensional accuracy of four impression materials for fixed denture
Shizhu BAI ; Yimin ZHAO ; Xiaolan YE
Journal of Practical Stomatology 2001;17(3):239-242
Objective:To investigate the three-dimensional accuracy of four impression materials for fixed denture:silicone(OX),hydrocolloid(HT) and two kinds of alginate impression(FC and ZS).Methods:Ten plaster replication models for each impression materials were made on the same metal master cast respectively, vertical and horizontal dimensions between landmarks on the masters and plaster casts were measured with an optical microscope. ANOVA was used to compare the measurements among the materials.Results:The difference between the masters and casts in horizontal distances measured on ZS produced models was bigger than that on other impression material produced ones (P<0.01) and beyond clinical requirment.The difference between the masters and casts in all measured dimensions on OX produced models was the smallest.Conclusion:Alginate paste is not accurate enough for denture model,while silicone is.The hydrocolloid material is relatively accurate.
8.The application of telescopes in the restoration of alveolar process cleft and the defects of front maxillae
Zhao YIMIN ; Lshigami TOMO ; Li QIHUA
Journal of Practical Stomatology 1995;0(04):-
Objective: To explore the possibility to restore alveolar process cleft and the defects of front maxillae with telescope techniques. Methods: 4-5 telescopes were used as retainers of a prosthesis for cleft alveloar process or the defects of front maxillae; metal framework was used as connector of abutments and obturator in soft-tissue defect. Porcelain or resinmetal crowns were applied to restore defects in dentition. Acrylic resin was applied to repairs the deftcts of alveolar process and front maxillae or defect of palate. By above ways, prostheses were fabricated, the patients were followed up. Results:The following up for 26-28 months in 6 cases showed that the prosthesis retained with telescopes had follow advantages: good retention, convenient application, high masticatary function and satisfactory esthetics effects. Conclusion:The prosthesis with telescopes is feasible for the restoration of cleft alveolar process and the defects of front maxillae.
9.The effect of ozone aging on the physical properties of SY-1silicon elastomer
Yan CUI ; Yimin ZHAO ; Longquan SHAO
Journal of Practical Stomatology 2001;0(03):-
0.05) respectively. Conclusion: The SY 1 silicon elastomer have suitable physical, mechanical and anti ozone aging properties.
10.Applied anatomy study of nasopalatine duct
Xuegang NIU ; Yimin ZHAO ; Changxu ZOU
Journal of Practical Stomatology 2001;0(03):-
Objective: To study the anatomic structure of the nasopalatine duct and the neighboring bone,provide reference for implant surgery in the incisor region. Methods: Manual quantitative measurement of the nasopalatine duct were performed in 73 maxilla specimens (38 from male and 35 from female). Results: The angle between the anterior wall of nasopalatine duct and the nasal floor was 114.80??11.00?, the angle between the cortical plate of anterior maxilla and the nasal floor 107.28??10.75?, the length of the nasopalatine duct was (15.63?2.18) mm in male, and ( 14.59 ?1.96) mm in female, the width of nasal opening of the duct was ( 4.92 ?1.46) mm in male, and (5.73?1.50) mm in female, the width of oral opening of the duct was (3.23?0.60) mm in male and (3.83?0.92) mm in female, at the level of nasal floor, the distance between the anterior wall of the duct and cortical plate of anterior maxilla was (6.15?1.90) mm. Conclusion: In front of nasopalatine duct, implants should be implanted parallel to nasopalatine duct,with an angle about 115? between the implant direction and nasal floor. The bone in front of nasopalatine duct was thin,the diameter of implants applied here should be less than 4 mm.