ABSTRACT
OBJECTIVE@#To investigate the feasibility of a drill template for the placement of guided template of middle and upper thoracic percutaneous vertebroplasty in thoracic pedicle approach on digital design and 3D printing technology.@*METHODS@#The preoperative CT images of 20 patients with thoracic fracture were collected retrospectively. With the 3D soft tissue printing technology, the data was reconstructed by 3D imaging reconstruction software to produce 1∶1 three dimensional soft tissue model. The pedicle screw channel and the digital template were designed by the 3-matic module of Mimics15.0 software. After guide template was printed by 3D printer and three dimensional template was fixed on the model, 2.0 mm Kirschner was placed and the accuracy of a drill template was observed by CT scans, bone cement was injected through the puncture tube and verified with images. The time of nail guide design, guide template production and cost were recorded.@*RESULTS@#The effectiveness of three dimensional thoracic model and digital guided template of middle and upper thoracic percutaneous vertebroplasty of thoracic fractures in thoracic pedicle approach was confirmed. Kirschner was placed and the accuracy of screw placement was confirmed with CT scanning. Template and the corresponding anatomical landmark fitted well, bone cement had showed good filling. The average printing time of upper thoracic spine model with soft tissue, the mean time of nail guide design, guide template production and cost were (719.00±3.03) min, (12.30±1.01) min, (55.50±10.30) min and RMB 3 150 yuan on average respectively.@*CONCLUSION@#By means of individual design and 3D soft tissue printingtechnology, accurate placement of guided template of middle and upper thoracic percutaneous vertebroplasty could be realized.
Subject(s)
Humans , Pedicle Screws , Printing, Three-Dimensional , Retrospective Studies , Surgery, Computer-Assisted , VertebroplastyABSTRACT
Objective@#To establish the functional occlusal morphology of fixed prostheses by using functional generated path (FGP) technology on a three-dimensional-printed diagnostic crown in order to decrease the chance of occlusal adjustment during try-in procedure of the complete crown, and to avoid the risk of occlusal interference after cementation of prosthesis.@*Methods@#A double-blind clinical trial was performed. Ten subjects (4 males, 6 females) who needed a first molar complete crown restoration were enrolled in Department of Prosthodontics, Peking University School and Hospital of Stomatology from July 2018 to December 2018. The working models with the abutment teeth of the ten participants were scanned to obtain the digital models, then the occlusal surfaces of crown were formed by either FGP technology on a three-dimensional (3D) printed diagnostic crown and then were scanned directly for computer aided design and computer aided manufacture (CAD/CAM) crown fabrication as experiment group, or conventional technology based on database as control group. Then zirconia crowns were fabricated for two groups. During crown try-in of the two groups, preferred crowns of subjects were recorded, the occlusal contact criteria including the occlusal contact area (mm2), the heights of occlusal high spot (mm) before and after the adjustment of crowns were digitally analyzed, and the amount of adjustment (mm and mm3) were calculated on digital models by using a reverse engineering software (Giomagic Sudio & Quality). Differences of values were compared statistically with paired t-test (α=0.05).@*Results@#The amount for occlusal adjustment for crowns in the experiment group [(7.320±4.238) mm3] was statistically less than that in the control group [(20.178±9.650) mm3] (P<0.05), the occlusal contact area of experiment group [(11.430±4.102) mm2] was statistically bigger than that of the control group [(4.808±3.223) mm2] (P<0.05), the heights of occlusal high spots for crowns in the experiment group was (0.043±0.019) mm while it was (0.594±0.201) mm in the control group with statistically significant differences (P<0.05).@*Conclusions@#This method could lead to a crown with less adjustment of occlusion, less occlusal high spot and less risk of occlusal interferences.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the feasibility of a drill template for the placement of reverse intramedullary lag screws on the outside of the pubis based on digital design and 3D printing technology.</p><p><b>METHODS</b>The preoperative CT images of a 23-year-old male patient with pelvic fracture were collected retrospectively. According to the Young and Burgess classification, the type of pelvic fracture was LC IIwith the 3D printing technology. The data was reconstructed by 3D imaging reconstruction software to produce 1:1 three dimensional model. The screw channel and the individual drill template was designed by the softwares of Mimics 10.01 and Geomagic 12, the accuracy of a drill template was observed by X-rays and CT scans after the placement of 2.0 mm K-wires in the three dimensional template fixed on the model.</p><p><b>RESULTS</b>Three dimensional pelvic model and digital, individual drill template could meet the requirement of the placement of reverse interamodullary lay screw for the treatment of superior ramus of pubis fracture. K-wire was placed and the accuracy of screw placement was confirmed using the X-ray and CT scanning. Template and the corresponding anatomical landmark fitted well.</p><p><b>CONCLUSIONS</b>With the assistance of the individual design and 3D printing technology, the accurate placement of superior ramus of pubis fracture screws can be realized. This technology is helpful to reduce the operation time and X-ray exposure of the patients and doctors.</p>