Precise Screw Positioning at the Mandibular Angle (original) (raw)
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Egyptian Dental Journal, 2019
Maxillary segment repositioning is essential for esthetic and functional outcomes. Increased success and experience achieved with computer guided Le Fort I osteotomy turned the attention to develop surgical techniques to cope with deficient maxilla solving the problem of the timeconsuming manual steps of intermediate wafer fabrication in addition to its inability to adjust the correct vertical position of the maxilla in relation to the skull base. This study aimed to evaluate CAD/CAM generated osteotomy/ plates locating surgical guides in three-dimensional maxillary segment repositioning. Ten patients with maxillary hypoplasia were subjected to virtual model 3D skull models for titanium plates pre-bending. Screw holes were surgery forming corrected 3D skull models for construction of osteotomy / plates locating surgical marked to the corrected guides. Pre-bent plates were installed intra-operatively into the predetermined screw holes. Placement of the plates adjust the depressed maxilla three dimensionally. All patients were clinically and radiographically evaluated pre and post-operatively. Degree of three-dimensional corrective movement were measured and statistically evaluated. CAD/CAM generated osteotomy plates locating surgical guides were proved to be more reliable for three-dimensional maxillary .segment repositioning
International journal of health sciences
Statement of problem: Implant placement in the mandibular posterior regions is often challenging because of limited space and insufficient accessibility. Purpose: The purpose of this clinical study was to investigate the accuracy of computer-guided surgery with a long drill key to place implants in the mandibular posterior regions. Material and methods: Computer-guided implant surgery was performed for 15 participants requiring implants in mandibular posterior region. This procedure involved using 6mm long drill key to guide the 2.0 mm diameter drill. The planned and placed implant position were scanned and superimposed to evaluate the accuracy of the guide. Results: A total of 15 implants were place where the mean linear deviation was 0.4 mm (range, 0.15 to 1.30 mm) for the implant shoulder and 0.45 mm (range, 0 to 1.48 mm) for the implant apex. The mean angular deviation was 1.4 degrees (0.38 to 4.89 degrees). The mean depth deviation was 0.61 mm (0.10 to 1.85 mm). The differences...
The Art of Using Computer-Assisted Navigation Systems in Guided Implant Surgery: A Review
2021
Background and Aim: Computer-aided design/computer-aided manufacturing (CAD/ CAM) has been widely used in implant dentistry. Recent computer-guided dynamic navigation systems promise an accurate approach to minimally invasive implant placement. Robot-assisted surgery has been used in dentistry since 2017. The present study aims to review the properties, clinical outcomes, advantages, and limitations of navigation, robotics, and CAD/CAM in implant placement surgery. Materials and Methods: An electronic search of the literature was conducted mainly through PubMed, ScienceDirect, Cochrane Library, and Google Scholar databases. Studies in the English language were considered for inclusion if they evaluated robotics, CAD/CAM, and navigation in implant placement. Finally, 21 articles were selected. Results: Guided implant surgery is assumed accurate, precise, and reliable; it also has a lower complication rate compared to freehanded implant surgery. Surgical guides could be indicated for patients with limited mouth opening, tight interdental spaces, a strong gag reflex, and distal implants. Several studies have reported that computerassisted surgery improves the accuracy of implant placement. Expensive equipment, high costs, and gaps between the guides and drill bite are the disadvantages of digital implant placement. Conclusion: Computer-aided implant navigation systems can improve implant placement outcomes. Digital procedures have shown accurate outcomes in implant surgery. Despite the advantages of guided surgery, deviation of implant position from the planned position still occurs. However, improvements in digital dentistry are slowly overcoming these challenges.
Misjudgments at the Mandibular Angle
Journal of Craniofacial Surgery, 2010
Background: Distraction osteogenesis is a well known and frequently described technique in mandibular deformities. Buried intraoral devices have numerous advantages, but success hinges on precise positioning of the implants. Although computer navigation has repeatedly been described for craniofacial applications, research on navigating the mandibular region is scarce. Navigating the device placement for a mandibular distractor could become a viable method for distraction osteogenesis because of the possibility of certainty in achieving a defined device position. Materials and Methods: A clinical situation was simulated by a mandible model mounted inside a phantom head. The screws were positioned according to a virtual plan through transoral and transbuccal approaches, with and without navigation. Results: Without navigation, the mean deviation from the planned position was 4.9 mm (range, 0.9Y10.7 mm), with a clear tendency to position the screws in the easy-to-access regions. With navigation, the mean deviation was significantly lower at 1.5 mm (range, 0.1Y3.4 mm). Conclusions: Computer-assisted surgery can provide a high level of accuracy in the region of the mandibular angle, where precision is crucial for buried intraoral distraction devices.
American Journal of Orthodontics and Dentofacial Orthopedics, 2009
Introduction: Mini-implants are placed in restricted sites, requiring an accurate surgical technique. However, no systematic study has quantified technique accuracy to reliably predict the surgical risks. Therefore, a graduated 3-dimensional radiographic-surgical guide (G-RSG) was proposed, and its inaccuracy and risk index (RI) were estimated. Methods: The sample consisted of 6 subjects (4 male, 2 female), who used mini-implant anchorage. Ten drill-free screws (DFS) were placed by using the G-RSG. The central point of the mesiodistal septum width (SW) was the selected implant site on the presurgical radiograph. The distances between DFS and the adjacent teeth (5-DFS and 6-DFS) were measured to evaluate screw centralization and inaccuracy degree (ID). These distances were statistically compared by independent t tests, and inaccuracy was determined by the expression ID 5 (5-DFS -6-DFS)/2, which represents deviation of the mini-implant's final position regarding the central point initially selected. Then SW, ID, and screw diameter (SØ) were combined to estimate the surgical risk with RI expressed by RI 5 SØ/SW -ID. Results: The 5-DFS and 6-DFS distances were not significantly different. The ID of the G-RSG was 0.17 mm. The low ID ensured a safe RI (\1) in spite of the restricted SW. Conclusions: The G-RSG accuracy allowed fine prediction of the final DFS position in the interradicular septum, with a low RI, which is a helpful tool to estimate surgical risks. (Am J Orthod Dentofacial Orthop 2009;136:722-35)
Osteomark: a surgical navigation system for oral and maxillofacial surgery
International journal of oral and maxillofacial surgery, 2012
The purpose of this project was to test a surgical navigation tool designed to help execute a surgical treatment plan. It consists of an electromagnetically tracked pencil that is used to mark bone intraoperatively. The device was tested on a precision block, an ex vivo pig mandible and during performance of six endoscopic vertical ramus osteotomies on pig cadavers. The difference between actual pencil position and that displayed by the computer was measured three times each at ten 2mm holes on the block (n=30 observations) and on the ex vivo mandible (n=11 measurements). Errors between planned and actual osteotomy locations for the cadaver procedures were measured. The mean distance between known and displayed locations was 1.55 ± 0.72 mm on the precision block and 2.10 ± 0.88 mm on the pig mandible. The error measured marking the same point on the block multiple (n=5) times was 0.58 ± 0.37 mm. The mean error on the simulated osteotomies was 2.35 ± 1.35 mm. Osteomark was simple to ...
Accuracy of a Navigation System for Computer-Aided Oral Implantology
Lecture Notes in Computer Science, 2000
Placement of endosteal implants is a widespread therapy for re-establishing full functionality in edentulous patients. As a first application of VISIT, a modular software system for research into computeraided surgery developed at our hospital, we have implemented a navigation system for computer-aided implant dentistry (CAID). Besides improved accuracy, benefits of CAID include fast translation of preoperative imaging to the operating theatre and the possibility to insert the implants without having to prepare large mucosa flaps. In this cadaver study, we have measured the overall accuracy of VISIT for inserting four intraforaminal implants in the edentulous mandible. Five cadaver mandibles were embedded into plaster. After high-resolution CT scanning, the mandibles were registered, and the implant channels were drilled by the surgeon. Training implants were inserted into the implant channels, and the plaster was removed. Again, the mandibles underwent CT scanning, and the pre-and postoperative scans were registered relative to each other. A gross registration between pre-and postoperative scans was achieved using surface-or mutual information matching since in some cases the fiducial markers were lost. After transformation to a common coordinate system, the accuracy was assessed by measuring the distance of the implant's center to the cortex of the jawbone. Average accuracy of the navigation system was found to be 0.9 ± 0.7 mm, range {0.0. .. 3.5} mm. We conclude that these results show that CAID is an interesting novel application of computer-aided surgery superior to conventional methods in oral surgery.
Journal of Dental Sciences, 2012
Reconstruction plates have been used to bridge discontinuity defects after resection of mandibular tumors for many years. However, shaping and adapting the titanium plate during surgery is time consuming and technique sensitive especially for a large defect or a disease-deformed mandible. In this case report, a method is introduced to assist surgeons in pre-shaping a reconstruction plate before surgery, and with the aid of a position guide and drilling guide, the pre-surgically adapted reconstruction plates can be positioned at the planned position during surgery. This method improves surgical outcomes and decreases operating time.
Technical aspects of prosthetically guided maxillofacial surgery of the mandible. A pilot test study
Acta of bioengineering and biomechanics / Wrocław University of Technology, 2014
A test of the accuracy in transferring the virtual data into the surgical environment was carried out. Differences between the virtually planned and the actual position during surgery of the rapid prototyped guides and the bone plates were investigated. The accuracy of the method was evaluated in terms of the precision of cuts in the mandible, the final positions of the rami and condyles, and the sectioning precision of the fibula. The guide position presented a mean value dislocation of 0.6 mm in the right side and of 4.1 mm in the left side; the cut line of the mandible presented an angular deviation of 2.9° (right) and of 17.5° (left). The right condyle was positioned 2.5 ± 0.05 mm more medial than native position, and the left condyle 5.2 ± 0.05 mm medial. The total length was 0.3 ± 0.05 mm short of the virtually projected length at the inferior margin of the mandible and 1.9 ± 0.05 mm longer than projected at the superior margin. The Prosthetically Guided Maxillofacial Surgery ...
Journal of Healthcare Engineering, 2015
The aim of this study is to evaluate feasibility and accuracy of dental implant placement utilizing a dedicated bone-supported surgical template. Thirty-eight implants (sixteen in maxilla, twentytwo in mandible) were placed in seven fully edentulous jaws (three maxillae, four mandibles) guided by the designed bone-supported surgical template. A voxel-based registration technique was applied to match pre-and post-operative CBCT scans. T he mean angular deviation and mean linear deviation at the implant hex and apex were 6.4 ± 3.7°(0.7°− 14.8°), 1.47 ± 0.64 mm (0.5 − 2.56 mm) and 1.70 ± 1.01 mm (0.71 − 4.39 mm), respectively. The presented bonesupported surgical template showed acceptable accuracy for clinical use. In return for reduced accuracy, clinicians gain accessibility when using this type of surgical template for both the maxilla and the mandible. This is particularly important in patients with reduced mouth opening.