No abstract available.
Computer Graphics ; Otolaryngology

This study was designed to get the knowledge of the structual characteristics of the lingual dental arch shaper of Koreans. The subjects consisted of 107 nirmal occulsions. The lingual structure which was divided into two groups, anterior and posterior part, was measured and analyzed. 22 pairs of the 107 samples were usde to test the derived results. The findings of this study were as follows; 1. The mathmatical functions of the we curces which showed good fitting to the upper and lower anterior lingual arch were derived and drawed to the same acale using the computer graphics. 2. The results of the test showed a reasonable degree of accuracy to all of the 33 randm samples. 3. The average degrees of posterior flexions were obtained and could be used as a initial guide at the wire-bending.
Computer Graphics ; Dental Arch*

At present, doctors discuss the situation of scoliosis patients mainly through their x-ray photograph. Because of the complexity of human spine structure, it is very difficult for doctors to plan & simulate operation or instruct design of scoliosis bracket only through the x-ray photograph of patient. In this paper, the technology of forming an STL file from CT data was introduced. The solid model of a scoliosis patient was reconstructed and transferred to RPM system. A human scoliosis model with all spine anatomical structure was manufactured using laminated object manufacturing (LOM). It has important clinical value for doctors to plan & simulate operation, and it is significant for the development of integration of medicine and engineering.
Computer Graphics ; Computer Simulation ; Computer-Aided Design ; Humans ; Imaging, Three-Dimensional ; Models, Anatomic ; Scoliosis ; diagnostic imaging ; surgery ; Tomography, X-Ray Computed

PURPOSE: To evaluate the effect of surface treatments and repair materials on the shear bond strength and to measure the fracture toughness of CAD/CAM provisional restoration materials. MATERIALS AND METHODS: Four CAD/CAM (3D printing: Nextdent C&B and ZMD-1000B Temporary, CAD/CAM resin block: Yamahachi PMMA disk and Huge PMMA block) and four conventional (monometacrylate: Jet and Alike, dimetacrylate: Luxatemp and Protemp 4) materials were selected to fabricate disk-shaped specimens and divided into six groups according to surface treatment (n=10). CAD/CAM materials were repaired with Jet or Luxatemp, while conventional materials were repaired with their own materials. The shear bond strength was measured by using universal testing machine. Ten rectangular column-shaped specimens for each material were fabricated to measure the fracture toughness by single edge v notched beam technique. Statistical analysis was performed by one-way ANOVA. RESULTS: The highest shear bond strength of CAD/CAM materials was achieved by SiC paper + sandblasting. It was also accomplished when repairing 3D printing materials with Luxatemp, and repairing CAD/CAM resin blocks with Jet. Yamahachi PMMA disk showed the highest fracture toughness. Nextdent C&B showed the lowest fracture toughness value but no statistically significant difference from Alike and Luxatemp (P>.05). CONCLUSION: In order to successfully repair the CAD/CAM provisional restoration, mechanical surface treatment and appropriate repair material according to the CAD/CAM material type should be selected. The CAD/CAM provisional materials have proper mechanical properties for clinical use as compared to conventional materials.
Computer-Aided Design ; Polymethyl Methacrylate ; Printing, Three-Dimensional

Orthopedic 3D printed surgical navigational template is an instrument that is prepared by 3D reconstruction based on preoperative radiological data of the patient using computer-aided design (CAD) and 3D printing techniques. The 3D printed navigational template allows accurate intra-operative assessment of the relative spatial distance, angular relationship, direction and depth. The application of 3D printed navigational template technique in orthopedics surgeries achieves the conversion of preoperative planning from 2/3D graphics to 3D models, and provides a new method for individualized and precise treatment. Herein we review the evolution, clinical application, and basic classification of 3D printed navigation template technique, analyze its advantages and disadvantages, and discuss the current problems and the future development of this technique.
Computer-Aided Design ; Humans ; Orthopedic Procedures ; Printing, Three-Dimensional

Digital technologies use high-precision three-dimensional scanning, intelligence-aided design software, and multi-axis numerical control milling or 3D printing, which can produce restorations with reliable precision and suitable function. However, the development of digital technologies in the field of complete denture restoration has been slow due to the complexity of prosthesis. This review article introduces the current research status and clinical applications of digital complete dentures in prosthodontic clinics and dental laboratories to provide beneficial references to prosthodontists and dental technicians.
Computer-Aided Design ; Denture, Complete ; Printing, Three-Dimensional

A fabrication method of inner and outer crown using CAD/CAM is presented. The information of abutment teeth is transferred to a computer through a 3-dimensional scanner. A Konus inner and outer crown is designed on a computer and a real crown is machined based on this design using CAM. This method can save laboratory time and reduce inaccuracies compare to conventional casting procedure. A stone model with six prepared abutment teeth from a patient was used in this study. Three dimensional information from the model was transferred to a computer using a contact type 3dimensional scanner with a 25micrometer accuracy. All margins were identified on a computer image where there is a change in surface taper of a model. To provide a cement space, the image of a inner surface of a Konus inner crown was duplicated 25micrometer apart from the surface of a prepared abutment teeth image. The cement space was 20micrometer at the cervical margin. All Konus crowns were machined with a 10micrometer accuracy. It was concluded that this method can reduce working-time for the laboratory process and increase accuracy. A further research is required to make a simplified process for a more complex prosthesis.
Computer Graphics* ; Crowns* ; Humans ; Prostheses and Implants ; Tooth

Ancestry composition of populations and individuals has been extensively investigated in recent years due to advances in the genotyping and sequencing technologies. As the number of populations and individuals used for ancestry inference increases remarkably, say more than 100 populations or 1000 individuals, it is usually challenging to present the ancestry composition in a traditional way using a rectangular graph. To address this issue, we developed a program, AncestryPainter, which can illustrate the ancestry composition of populations and individuals with a rounded and nice-looking graph to save space. Individuals are depicted as length-fixed bars partitioned into colored segments representing different ancestries, and the population of interest can be highlighted as a pie chart in the center of the circle plot. In addition, AncestryPainter can also be applied to display personal ancestry in a way similar to that for displaying population ancestry. AncestryPainter is publicly available at http://www.picb.ac.cn/PGG/resource.php.
Computer Graphics ; Genetics, Population ; Humans ; Software

We measured the bone ingrowth rate on 22 retrieved human cementless porous coated acetabular cups by the help of computer graphics. All the acetabular cups had functioned well, and had had evidence of radiologic bony ingrowth before revising the acetabular cup. The reason for retrieval of the acetabular cups were: one with habitual dislocation, who with stem loosening, and 19 with polyethylene cup wearing. The period from initial surgery to retrieval surgery was 28 months to 108 months(average 56.1 months). All the retrieved porous coated acetabular cups showed macroscophic bony ingrowth, and the ratio of the whole porous surface to bony ingrowth area was showed 1.14% to 92.27% (average 36%).
Acetabulum ; Computer Graphics ; Dislocations ; Humans ; Polyethylene

STUDY DESIGN: Review article. OBJECTIVES: To present the latest knowledge on spine surgery using augmented reality (AR). SUMMARY OF LITERATURE REVIEW: AR is a new technology that simulates interactions with real-world surroundings using computer graphics, and it is a field that has recently been highlighted as part of the fourth industrial revolution. MATERIALS AND METHODS: Review of related literature and introduction of latest research. RESULTS: Spine surgery using AR is currently in its early stages. If industry, academia, and research institutes cooperate and develop, spine surgery using AR is highly likely to develop to the next level. CONCLUSIONS: Spine surgeons should strive to develop relevant technology.
Academies and Institutes ; Computer Graphics ; Spine ; Surgeons