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Objective: To investigate the influence of the design and application of novel surgical template on the accuracy of reconstructed mandibula and implant position in occlusion-guided functional mandibular reconstruction, so as to provide guidance for clinical treatment. Methods: Between January 2017 and May 2019, 11 patients with segmental mandible defects were treated, including 8 males and 3 females with an average age of 31.8 years (range, 19-45 years). There were 6 cases of ameloblastoma, 3 cases of keratocystic tumor, and 2 cases of ossifying fibroma. According to Urken classification of mandible defects, there were 1 case of CRB, 4 cases of RB, 2 cases of RBS, and 4 cases of SB. According to the occlusion relationship, a novel surgical template with the reconstruction titanium plate screws and implants drill-guided information was designed and manufactured. With the help of the novel surgical template, the "one and a half" fibula reconstruction mode was used for jaw functional reconstruction, and the implant supported denture was finally completed. The postoperative CT at 1 week were collected to analyze the morphology of the preoperative virtual design jaw and postoperative jaw. The coincidence of fibular reconstructed mandible (fibular upper barrel, fibular reconstructed ramus and condyle, and whole mandible) and implant in mandible were calculated. When the coincidence was less than 80%, it was considered that the deviation was obvious. Oral panoramic X-ray film and cone beam CT were examined at 6 months after operation to evaluate the osseointegration before implant repair. Results: None of the 11 flaps had postoperative vascular crisis. One flap occurred necrosis at 1 month after reconstruction combined with 3 implants failed, and had been removed at 6 months after reconstructed surgery; the others had no flap necrosis. One week postoperatively, the coincidence of the fibular upper barrel was 87.55%±3.08%, the whole mandible was 82.68%±5.94%, and the implant in mandible was 88.00%, with significant differences ( t=8.131, P=0.000; t=2.118, P=0.046; Z=4.070, P=0.000) when compared to 80%, respectively. The fibular reconstructed ramus and condyle was 77.82%±3.54%, with no significant difference ( t=-2.042, P=0.068) when compared to 80%. Six months postoperatively, oral panoramic X-ray film and cone beam CT showed that all 22 implants achieved osseointegration and the palatal mucosa transplantation was performed, then finally completed the denture rehabilitation at 6-9 months after operation. All patients were satisfied with their postoperative appearance. Conclusion: The novel surgical template can guarantee the accuracy of functional mandible reconstruction guided by occlusal guidance, and ultimately achieve the beautiful contour of jaw and occlusal function reconstruction, and improve the patient's life quality.
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BACKGROUND: Anterior cervical transpedicular screws placement technique provides nice mechanical stability and is of very promising application prospects. However, the technology is difficult to operate and has a high risk, and has not been widely used. OBJECTIVE: To design a new three-dimensional (3D) printing template for bilateral anterior cervical transpedicular screws placements and assess its feasibility and safety in anterior cervical pedicle screw placement. METHODS: Six cadaveric cervical specimens, including three males and three females, were used in this experiment. Data of thin layer CT scanning of the specimens were saved in DICOM format and then imported into Mimics 17.0 software. Following 3D reconstructions of the cervical spine, guiding holes for C3-C7 bilateral anterior cervical transpedicular screws trajectories were designed; pedestals for the guiding holes were then designed via reversely thickening the bony structure of the anterior and 1/2 superior-anterior surface of vertebral body, and 1/2 anterior joint surface of bilateral processus uncinatus. Practical objects of the templates were obtained via 3D printing and were then used for guiding bilateral anterior cervical transpedicular screws replacements from C3 to C7. CT scanning was conducted again and the accuracy of anterior cervical transpedicular screws replacements was evaluated from sectional CT images. The difference of deviational angles on axial plane (α1, α2) and sagittal plane (β1, β2) between real and simulated trajectories were compared in Mimics 17.0 software. RESULTS AND CONCLUSION: (1) A total of 60 anterior cervical transpedicular screws were successfully inserted; 57 screws were completely located in pedicles and were judged as grade 0, representing an accuracy of 95.0%. The other three anterior cervical transpedicular screws perforated from pedicles, including grade 1 perforation in two screws (3.3%) and grade 2 perforation in one screw (1.7%). (2) By comparing real and simulated trajectories, the medical and lateral deviational angles were (0.867±0.787)° and (0.783±0.792)°, respectively (P > 0.05); the cephalad and caudal deviational angles were (1.362±1.380)° and (1.314±1.300)°, respectively (P > 0.05). (3) With the help of the 3D printing template designed in this study, bilateral anterior cervical transpedicular screws replacements could be smoothly carried out at high inserting safety.
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Objective@#To investigate the feasibility and accuracy using digital surgical guide to position the jaws in bimaxillary orthognathic surgery.@*Methods@#16 patients with dento-maxillofacial deformity were included from January to December 2018 in Nanjing Stomatological Hospital. There were 10 males and 6 females, all of which were skeletal Ⅲ deformity. The mean age was 21.3 years old (16 to 28 years). They were divided into digital guide (group A) and traditional model surgery (group B) according to the treatment sequence. All patients underwent both Lefort Ⅰ osteotomy and bilateral ascending sagittal split. Virtual surgery was performed and digital three-dimensional surgical template was printed before surgery in group A. During the operation, digital surgical templates were used to position maxilla and mandible. The accuracy was evaluated by generating color distribution map of deviation grade, which was imaging fusion of virtual surgical jaw position and actual surgical jaw position to measure the deviation distance of each marker point one week after surgery. The deviations between the preoperative design and the actual operation were compared with the t-test respectively in group A and group B, and the independent sample t test was chosen to compared the accuracy of reduction between the two groups in sagittal, horizontal, and vertical directions.@*Results@#All 16 patients had primary healing. The maximum deviation of the patients in group A was at U6. The deviation direction was vertical, and the deviation distance was (1.67±0.32) mm. In group A, the deviation distances of all marker points in the sagittal, horizontal and vertical directions were (0.55±0.26) mm (t=2.985, P=0.205), (0.62±0.20) mm (t=2.672, P=0.193) and (1.07±0.62) mm (t=5.122, P=0.823), respectively. The result in group B was (0.63±0.28) mm(t=3.397, P=0.307), (0.71±0.42) mm (t=4.438, P=0.541) and (1.82±0.36) mm (t=1.115, P=0.021) in these directions. There was no significant difference between two groups in the sagittal (t=4.704, P=0.763) and lateral (t=4.008, P=0.615) directions, and the difference in the vertical (t=1.432, P=0.037) direction was statistically significant.@*Conclusions@#The digital guides were feasible to position jaws accurately in orthognathic surgery.
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Objective@#To design the aesthetic new gonion and osteotomy line for patients with prominent mandibular angle patients using computer-aided techniques, and to investigate the application of three-dimensional digital planning in gonioplasty.@*Methods@#From April 2016 to April 2017, 14 female patients with prominent mandibular angle underwent preoperative surgical design and surgical simulation using digital technology. Gonioplasty was performed under the guide of surgical templates, preoperative, surgical simulation and postoperative data were measured including bilateral mandibular angles, the height of ramus(Co-Go) and the length of mandibular body(Go-Me). Paired t test was used to compare the differences between surgical simulation and postoperative measurements.@*Results@#Gonioplasty was performed in 14 patients successfully, and all were satisfied with their facial outcomes. The mandibular angle was improved from 113.86°±4.11° to 124.52°±1.26° on the left side, and 114.30°±4.01° to 124.29°±1.24° on the right side respectively. The average ratio of Go-Me/Co-Go was 2.011 on both sides after operation, which was very close to surgical planning. No significant differences were found between surgical planning and postoperative measurements with respect to mandibular angle or the ratio of Go-Me/Co-Go on both sides(P>0.05). The deviations between them were 1.00°±0.68° and 0.058±0.038 on the left side, and 0.85°±0.63° and 0.072±0.053 on the right side respectively.@*Conclusions@#Computer-assisted gonioplasty could improve the efficiency and accuracy of surgery, reduce the risk of surgical complications, and attain higher patients′ satisfaction.
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@#With the increasing development of digital technologies, digital surgical templates have been widely used in stomatology. However, the accuracy of digital surgical templates is always a consideration for many researchers and dentists. This article analyzed the factors affecting the accuracy of digital surgical templates and found that errors arise from six factors, including the design and manufacture of the templates, implant guide support, implant systems and guide systems, implant length, bone density and the clinical experience of the operator; this literature review aims to reduce or eliminate human factors and improve accuracy, objectivity and security in implant placement.
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Objective@#To evaluate the accuracy of digital surgical guide in tilted implant in the maxillary posterior region.@*Methods @# Jaw data from 14 patients were scanned using cone beam computed tomography (CBCT), and digital models were acquired by scanning maxillary plaster models. Implant software was employed to process jaw data and digital models in order to design the surgical template. Then the stereolithographic (SLA) surgical template was created to guide the surgery. After that CBCT data was collected again and compared with the data collected before. Deviations between the actual implant position and the planned implant position were analyzed. @*Results@#Central deviation at the hex and apex between the actual implant and the planned implant was almost constant with a mean of (0.625 ± 0.183) mm and (0.820 ± 0.208) mm. Mean value of horizontal deviation at the hex was (0.314 ± 0.070) mm, horizontal deviation at the apex was (0.509 ± 0.139) mm, vertical deviation at the hex was (0.538 ± 0.178) mm, vertical deviation at the apex was (0.638 ± 0.178) mm. @*Conclusion@#Angled implantation in the maxillary posterior region can reduce risks and trauma as well as the difficulties and duration of surgery. However, our data suggested that significant deviations existed in the actual implant position and the planned implant position.
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Objective @#The purpose of this study is to determine the accuracy of implant placement in the edentulous jaw using computer planning and fully-guided mucosa-supported surgical template by Simplant software.@*Methods@#63 implants were placed in 9 patients (11 fully edentulous jaws), 26 implants were placed in upper edentulous jaw and 37 implants in lower edentulous jaw. Preoperatively, first, a cone beam CT was required for patients with radiographic template and radiographic template respectively. Therefore, the data of CBCT was inputted in Simplant software by DICOM format, followed by virtual implant planning. Hereafter, a mucosa-supported surgical template was designed by dentist and made by Masterilise company to allow implant placement using the template as a guide. To investigate the accuracy of implant placement, a postoperative CBCT scan was obtained and matched to the preoperative scan. The accuracy of implant placement was validated three-dimensionally including divations of implant shoulder, apical point, axial angulation and depth.@*Results@#The survival rate of 63 implamts for a 6 month to 10 year observation period was 100%. The mean divation of implant shoulder was 0.73 ± 0.53 mm, implant apical point was 1.15 ± 0.62 mm, implant depth was 0.95 ± 0.64 mm and implant axial angulationwas 4.10 ° ± 3.23°.@*Conclusion @#Divation between virtual and actual implant was existed and it should be considered preoperatively when virtual implant was planned to avoid injuring anatomic structure and keeping surgery safely. Correct manipulation during implant operation are helpful to decrease the divation of implant placement.
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STUDY DESIGN: Cadaveric study. PURPOSE: The purpose of this study was to assess the accuracy and feasibility of cervical pedicle screw (CPS) insertion into the subaxial cervical spine placed using a patient-specific drill guide template constructed from a stereolithographic model. OVERVIEW OF LITERATURE: CPS fixation is an invaluable tool for posterior cervical fixation because of its biomechanical advantages. The major drawback is its narrow corridor that allows very little clearance for neural and vascular injuries. METHODS: Fifty subaxial pedicles of the cervical vertebrae from five cadavers were scanned into thin slices using computed tomography (CT). Digital imaging and communications in medicine images of the cadaver spine were digitally processed and printed to scale as a three-dimensional (3D) model. Drill guide templates were manually moulded over the 3D-printed models incorporating pins inserted in the pedicles. The drill guide templates were used for precise placement of the drill holes in the pedicles of cadaveric specimens for pedicle screw fixation. RESULTS: The instrumented cadaveric spines were subjected to CT to assess the accuracy of our pedicle placement by an external observer. Our patient-specific drill guide template had an accuracy of 94%. CONCLUSIONS: The use of a patient-specific drill guide constructed using stereolithography improved the accuracy of CPS placement in a cadaveric model.
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Female , Cadaver , Cervical Vertebrae , In Vitro Techniques , Pedicle Screws , Printing, Three-Dimensional , Spine , Vascular System InjuriesABSTRACT
Surgical guide not only provide diagnosis and treatment plan, but even location and direction of implantation. Surgical guide could be divided into non-limited design, partially limited design, and completely limited design. Partially limited design is easily manufactured and inexpensive but less accuracy, compared to completely limited design. From this approach, partially limited design may be particularly effective in patients who present with a single missing tooth or partially edentulous teeth. Completely limited design is anatomically accuracy, esthetical and functional, optimized treatment for prosthetic and biomechanical perspective, and also minimizes discomfort for post-treatment. The purpose of this study is to review previous studies of various surgical guides and applying in clinic.
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Humans , Diagnosis , Stents , ToothABSTRACT
Subject(s)
Aged , Female , Humans , Mandible , Mucous Membrane , Neck , Prostheses and ImplantsABSTRACT
PURPOSE: The template-guided implant surgery offers several advantages over the traditional approach. The purpose of this study was to evaluate the accuracy of coordinate synchronization procedure with 5-axis milling machine for surgical template fabrication by means of reverse engineering through universal CAD software. MATERIALS AND METHODS: The study was performed on ten edentulous models with imbedded gutta percha stoppings which were hidden under silicon gingival form. The platform for synchordination was formed on the bottom side of models and these casts were imaged in Cone beam CT. Vectors of stoppings were extracted and transferred to those of planned implant on virtual planning software. Depth of milling process was set to the level of one half of stoppings and the coordinate of the data was synchronized to the model image. Synchronization of milling coordinate was done by the conversion process for the platform for the synchordination located on the bottom of the model. The models were fixed on the synchordination plate of 5-axis milling machine and drilling was done as the planned vector and depth based on the synchronized data with twist drill of the same diameter as GP stopping. For the 3D rendering and image merging, the impression tray was set on the conbeam CT and pre- and post-CT acquiring was done with the model fixed on the impression body. The accuracy analysis was done with Solidworks (Dassault systems, Concord, USA) by measuring vector of stopping's top and bottom centers of experimental model through merging and reverse engineering the planned and post-drilling CT image. Correlations among the parameters were tested by means of Pearson correlation coefficient and calculated with SPSS (release 14.0, SPSS Inc. Chicago, USA) (alpha = 0.05). RESULTS: Due to the declination, GP remnant on upper half of stoppings was observed for every drilled bores. The deviation between planned image and drilled bore that was reverse engineered was 0.31 (0.15 - 0.42) mm at the entrance, 0.36 (0.24 - 0.51) mm at the apex, and angular deviation was 1.62 (0.54 - 2.27)degrees. There was positive correlation between the deviation at the entrance and that at the apex (Pearson Correlation Coefficient = 0.904, P = .013). CONCLUSION: The coordinate synchronization 5-axis milling procedure has adequate accuracy for the production of the guided surgical template.