ABSTRACT
ObjectiveTo clarify the feasibility of the 3D scanning volume method for distal upper limb volume measurement, and to analyze its scorer reliability and criterion-related validity. MethodsFrom January to March, 2022, a therapist (operator A) who had not been exposed to 3D scanning volume method and water displacement method was trained to use a handheld 3D laser scanner and a spilt cup to measure the volume of a PVC distal upper limb model. The operation time of 30 operations of each method was recorded. The learning curves of the two methods were plotted using cumulative sum (CUSUM) analysis. The curve was cut into the learning stage and the mastery stage by the vertex of peak. The times required to reach the mastery stage and the operation time of the mastery stage for the two methods were recorded. A total of 20 healthy subjects were recruited from Huashan Hospital of Fudan University. Two trained therapists (operator A and operator B) measured the bilateral distal upper limb volume using a handheld 3D laser scanner, and operator A measured the bilateral distal upper limb volume using a spilt cup. ResultsThe fitting learning curve of the 3D scanning volume method (R² = 0.984) reached its peak after eight times of operation; while that of the water displacement method (R² = 0.494) reached its peak after five times of operation. At mastery stage, the operator spent less time using 3D scanning volume method than using water displacement method (P < 0.05). The intraclass correlation coefficient between the two operators were both 0.979 for bilateral distal upper limb volume measure (P < 0.001). The Pearson coefficients was above 0.979 between 3D scanning volume method and water displacement method (P < 0.001). ConclusionA therapist can master the use of the 3D scanning volume method after eight times of operation, and the operation time of 3D scanning volume method is shorter than that of water displacement method at mastery stage. The 3D scanning volume method is well reliable and valid, that can be used as an alternative to the water displacement method for distal upper limb volumetric measurement.
ABSTRACT
Objective 3D-scanning system is put in use to evaluate the comparative effect be-tween the cell-assisted lipotransfer (CAL) and traditional autologous fat transplantation ,which aims to definitize the survival rate of fat after CAL and provide a reference for the clinic .Methods Fourteen cases were collected among patients aquiring facial autologous fat transplantation from February to May 2016 from the hospital out-patient department ,which were then divided into two groups equally and randomly .7 patients used traditional autologous fat transplantation form the control group and the rest 7 used the CAL .Autologous fat sample of the CAL group was grafted with stromal vascular frac-tion (SVF) .All the patients received follow-up examination and the period lasted at least 6 months . 3D-scanning of facial models were conducted sometime before surgery ,a week after surgery and also 3 months after surgery .Results The average transplantation volume of CAL group was 13 .86 ml while the control group was 12 .14 ml .There were no significantly differnt in the transplantation volumes of the fat (P > 0 .05) .The survival rate of fat in CAL group was 37 .82％ while the control group was 27 .54％ after calculating the changing volume from the facial models .The survival rate of fat in CAL group was significantly higher than that in the control group (P < 0 .05) .Conclusions 3D-scanning system can provide the data concerning the lipotransfer and calculate the survival rate of the fat .CAL can raise the survival rate of the fat .
ABSTRACT
Objective To investigate the application of 3D scanning system in medical education technology.Methods David 3D scanning system had its advantages,calibration technique,working flow and post-processing of scanning data described,and then introduced into medical education and underwent series of tests.Results David 3D scanning system gained high modeling speed,and spent only 2 h for actual specimen scanning,modeling as well as synchronized collection and mapping.The scanning accuracy reached industrial level.Conclusion David 3D scanning system gains advantages over the traditional 3D scanning technique,and facilitates medical digital modeling by transforming object information into digital signal.
ABSTRACT
The dental student should have thorough knowledge of the dental morphology and develop adequate manual skill to reproduce any part of the tooth, thus maintaining the perfect correlation with associated structures. Computers are becoming an integral part of dental education and dental practice, especially for the acquisition of information in three dimensions and the production of solid objects from computer models. The aim was to present educational material that would allow the dental student to learn to easily identify the morphologic characteristics of permanent teeth, using new technological tools. In order to do this, healthy permanent teeth were scanning by NextEngine 3D Scanner HD using the MultiDrive. A 360° scan in macro range was chosen in each case. The number of scans for this family was 16, due to surface irregularities that require readings from a greater number of angles. Volumes of external structures of the scanned tooth were generated and stored in *.STL files. Virtual models were transferred in to programs used for producing physical prototypes that faithfully reproduce anatomy of interest using ReplicatorG software and MBot Grid II 3D printer. 3D virtual and printed macro models of permanent teeth were obtained. This models allows an excellent visualization of the morphological characteristics of permanent teeth. 3D virtual and printed teeth, derived from real tooth, are intended to be a valuable learning tool that can be used in addition to or instead of extracted teeth and they are anticipated to represent an improvement over plastic teeth.
El estudiante de odontología debe tener un conocimiento profundo de la morfología dental y desarrollar la habilidad manual adecuada para reproducir cualquier parte del diente, manteniendo así la correlación perfecta con las estructuras asociadas. La tecnología se está convirtiendo en una parte integral de la educación y la práctica dental, especialmente por la generación de información en tres dimensiones y la producción de objetos sólidos a partir de modelos computadorizados. El objetivo fue desarrollar material educativo que permita al estudiante de odontología aprender a identificar fácilmente las características morfológicas de los dientes permanentes, utilizando las nuevas herramientas tecnológicas. Dientes permanentes sanos maxilares y mandibulares fueron digitalizados utilizando un escáner 3D HD NextEngine mediante sistemática MultiDrive. Una exploración de 360° en rango macro fue elegido en cada caso. El número de escaneos para cada diente de 16, debido al nivel de detalle e irregularidades de las superficies dentarias que requieren lecturas de un mayor número de ángulos. Los volúmenes externos de los dientes escaneados fueron generados y almacenados en archivos *.STL. Las reconstrucciones generadas fueron transferidas para la producción de prototipos físicos que reproducen fielmente la anatomía de interés utilizando el programa ReplicatorG y la impresora Mbot Grid II 3D. Se obtuvieron modelos virtuales 3D y macro modelos impresoss en 3D de los dientes permanentes. Estos modelos permiten una excelente visualización de las características morfológicas. Los modelos dentarios virtuales e impresos en 3D, derivados de un diente real, son una valiosa herramienta de aprendizaje que se puede utilizar además de o en lugar de dientes extraídos, y representan una mejora anatómica sobre los modelos de dientes plásticos utilizados actualmente.
Subject(s)
Dentition, Permanent , Education, Dental/methods , Imaging, Three-Dimensional , Models, Anatomic , Printing, Three-DimensionalABSTRACT
PURPOSE: The accuracy of a gypsum model (GM), which was taken using a conventional silicone impression technique, was compared with that of a polyurethane model (PM), which was taken using an iTero(TM) digital impression system. MATERIALS AND METHODS: The maxillary first molar artificial tooth was selected as the reference tooth. The GMs were fabricated through a silicone impression of a reference tooth, and PMs were fabricated by a digital impression (n=9, in each group). The reference tooth and experimental models were scanned using a 3 shape convince(TM) scan system. Each GM and PM image was superimposed on the registered reference model (RM) and 2D images were obtained. The discrepancies of the points registered on the superimposed images were measured and defined as GM-RM group and PM-RM group. Statistical analysis was performed using a Student's T-test (alpha=0.05). RESULTS: A comparison of the absolute value of the discrepancy revealed a significant difference between the two groups only at the occlusal surface. The GM group showed a smaller mean discrepancy than the PM group. Significant differences in the GM-RM group and PM-RM group were observed in the margins (point a and f), mesial mid-axial wall (point b) and occlusal surfaces (point c and d). CONCLUSION: Under the conditions examined, the digitally fabricated polyurethane model showed a tendency for a reduced size in the margin than the reference tooth. The conventional gypsum model showed a smaller discrepancy on the occlusal surface than the polyurethane model.
Subject(s)
Calcium Sulfate , Models, Theoretical , Molar , Polyurethanes , Silicones , Tooth , Tooth, ArtificialABSTRACT
Objective To evaluate the application of three-dimensional (3D) scanning in the measurements and analyses of breast morphology changes that occur after breast augmentation. Methods Pre- and postoperative breast 3D images were obtained in 18 patients (36 breasts) undergoing augmentation mammaplasty by 3D scanning. All implants were round sillicone and planted under pectoral muscle. Average implant volume was 232.2 mL, and average projection was 3.46 cm. The number of implants in low profile implant group was 12( h ＜ 3.0 cm), and 16 in moderate group ( 3.0 ≤ h ＜ 4.0 cm), 8 in high group ( h ≥ 4.0 cm). The following parameters were measured by Geomagic 10.0: volume, projection, angle and distance of key landmarks, and symmetry degree. Results The increased volume of breast was corresponding with the implant volume (P ＞0.05). Postoperative breast projection was 12.9 %, less than expected projection (preoperative + implant projection). The values in low, moderate, and high profile group were 5.2 %, 15.1%, and 20.2 %,respectively. Conclusion 3D scanning is a quick, convenient, accurate and non-contact method for measurement of breast morphology, and it is promising in breast plastic surgery in the future.