Computer-guided Surgery Research Articles

Mandibular Rehabilitation Using Immediate Implant Loading After Computer-Guided Surgery

Computed tomographic scan is a precise complementary examination of diagnostic imaging and a noninvasive surveying technique that enables the professional to improve precision of implant placement by building a prototype that allows the confection of surgical guides. The authors present a clinical case of mandible rehabilitation based on computed tomography of a patient; the cross sections were reformatted and used to construct a virtual planning of the implants and a guide template in Dental Slice. Immediate loading of 5 titanium implants were placed in the mandible using a Slice Guide System. This technique allows a better surgical planning, makes the procedures more accurate, and reduces surgery time.

Guided surgery for a simple and predictable implant placement

The dental implant procedure has a long and proven track record to be one of the most predictable in terms of treatment outcome. This procedure has integrated itself as a part of routine treatment plans in dental offices because of increasing popularity and patient acceptance. In order to uphold this success, optimum diagnosis and treatment planning is crucial. Hence, computerized tomography aided imaging and template-guided surgery plays an important role in pre-placement planning and helps ensure positive outcomes. This article describes the benefits of computer-guided surgery as compared with conventional implant placement procedures, along with a case report. Clinical Relevance to Interdisciplinary Dentistry Implant therapy requires a multidisciplinary approach. The prosthodontist needs to plan the situation with the end prosthesis in mind. The periodontist needs to preserve the already compromised bone. The surgeon needs to navigate the implant into critical areas.

Zygomatic Implant Placement With Flapless Computer-Guided Surgery: A Proposed Clinical Protocol

The aim of the present report is to describe a procedure for zygomatic implant placement using image-guided implant surgery. This is an innovative technique and includes a new clinical approach to provide the direction to guide drilling. The ethical committee of the University of Genoa approved the study. All patients had clinical indications of severe maxillary atrophy (Class 4 Cadwood-Howell). A total of 25 implants were placed, of which 17 were in the premaxilla, 7 in the zygomatic area, and 1 in the pterygoid bone. The treatment was performed in 2 phases. The first phase included cone-beam acquisition to exclude sinus disease and evaluate the anatomy of the residual premaxillary bone in 3 dimensions. The success of osseointegration achieved by the primary implants (PIs) was confirmed after temporary loading and before proceeding with the second phase, in which all patients were scheduled for zygomatic implants. A total of 3 or 4 regular platform MK III implants (17 in all) were placed in the premaxilla using conventional implant surgery. A model within the analogs of the PIs was prepared (master model), taking a conventional impression. Next, a radiologic template was prepared on the same master model and stabilized on the PIs, using dedicated prosthetic components. The guide was screwed onto the PIs during computed tomography acquisition to determine a fixed and repeatable position of the guide. In the second phase, after routine planning, a mucosa-supported stereolithographic SurgiGuide with sleeves for the zygomatic implants and the corresponding stereolithographic model, including the mucosa, were received from the manufacturers. The guide was repositioned on the master model to replace the sleeves for the PIs in the same position. With an original customized surgical kit, including an innovative intrasinus device, we next simulated surgery on the stereolithographic model to determine and control the direction of the osteotomies and the final depth of drilling. The SurgiGuide was anchored onto the PIs before the zygomatic osteotomy, after which flapless surgery was performed to place the zygomatic implants according to the plan. Two PIs in the premaxillary area failed (and were replaced before the zygomatic step). No zygomatic implants failed. The follow-up examinations at 4 to 39 months showed good esthetic, phonetic, and functional results. The results of the proposed surgical procedure appear to be encouraging. Although it is difficult to achieve the correct driven angle of osteotomies for zygomatic implants, in all patients we achieved correct zygomatic positioning, in agreement with previous planning. Additional research and randomized clinical trials are needed to assess the predictability of the procedure.

Immediate implant loading following computer-guided surgery

The aim of this study was to develop and apply a new method for easy intraoperative adjustment of a provisional fixed full-arch restoration, in order to allow immediate implant loading following computer-guided surgery, regardless of any implant positioning errors compared to the virtual planning. In accordance with the NobelGuide™ protocol, a provisional restoration for immediate loading of six maxillary implants was prepared prior to surgery. Because small shifts between the planned and the actual implant positions were to be expected, the provisional restoration was not fabricated directly on temporary cylinders as a conventional one-piece superstructure, but was divided into two portions: six custom made abutments and a long span fixed restoration which were left unconnected. After implantation, the custom abutments were attached to the six implants to be immediately loaded, and the superstructure was cemented simultaneously to all abutments using dual cure resin cement. After the excess cement was cleaned and polished, the superstructure was then reseated. Passive fit was achieved between implants and the superstructure. The superstructure described in this article can be easily seated and adjusted to accommodate any possible shifts in implant positioning occurring during computer-guided surgery. Through this method uneventful immediate implant loading can be achieved in a reasonable operative time.

Computer-Navigated Contouring of Craniofacial Fibrous Dysplasia Involving the Orbit

Virtual surgical planning and computer-aided surgery were used to treat a mono-ostotic fibrous dysplasia of the right zygoma. Mirroring of the contralateral zygoma sets the target for the contouring of the affected zygomatic bone. An optical system for computer-guided surgery was used. Instruments were calibrated and visualized in real time on screen. Achievement of the virtually set target for the orbitozygomatic anatomy was assessed during surgery. Postoperative computed tomography and clinical follow-up confirmed an excellent result with regard to facial symmetry and eye bulb position. The volume of the orbit was increased from 24.2 to 26.0 mL compared with a contralateral orbital volume of 25.7 mL. Computer-guided surgery may be a useful tool in the surgical reduction of craniofacial fibrous dysplasia.

Computer-Guided Surgery in Implantology

The aim of the present study was to conduct a critical literature review about the technique of computer-guided surgery in implantology to highlight the indications, purposes, immediate loading of implants and complications, protocol of fabrication, and functioning of virtual planning software. This literature review was based on OLDMEDLINE and MEDLINE databases from 2002 to 2010 using the key words "computer-guided surgery" and "implant-supported prosthesis." Thirty-four studies regarding this topic were found. According to the literature review, it was concluded that the computer-assisted surgery is an excellent treatment alternative for patients with appropriate bone quantity for implant insertion in complete and partially edentulous arches. The Procera Nobel Guide software (Nobel Biocare) was the most common software used by the authors. In addition, the flapless surgery is advantageous for positioning of implants but with accurate indication. Although the computer-guided surgery may be helpful for virtual planning of cases with severe bone resorption, the conventional surgical technique is more appropriate. The surgical guide is important for insertion of the implants regardless of the surgical technique, and the success of immediate loading after computer-guided surgery depends on the accuracy of clinical and/or laboratorial steps.

Accuracy of a laboratory-based computer implant guiding system

Computer-guided implant placement is a growing treatment modality in partially and totally edentulous patients, though data about the accuracy of some systems for computer-guided surgery is limited. The purpose of this study was to evaluate the accuracy of a laboratory computer-guided system. A laboratory-based computer guiding system (M Guide; MIS technologies, Shlomi, Israel) was used to place implants in a fresh sheep mandible. A second computerized tomography (CT) scan was taken after placing the implants . The drill plan figures of the planned implants were positioned using assigned software (Med3D, Heidelberg, Germany) on the second CT scan to compare the implant position with the initial planning. Values representing the implant locations of the original drill plan were compared with that of the placed implants using SPSS software. Six measurements (3 vertical, 3 horizontal) were made on each implant to assess the deviation from the initial implant planning. A repeated-measurement analysis of variance was performed comparing the location of measurement (center, abutment, apex) and type of deviation (vertical vs. horizontal). The vertical deviation (mean -0.168) was significantly smaller than the horizontal deviation (mean 1.148). The laboratory computer-based guiding system may be a viable treatment concept for placing implants.

Relationship between cutting errors and learning curve in computer-assisted total knee replacement

Computer-assisted total knee replacement (TKR) has been shown to improve radiographic alignment. Continuous feedback from the navigation system allows accurate adjustment of the bone cuts, thus reducing errors. The aim of this study was to determine the impact of experience both with computer navigation and knee replacement surgery on the frequency of errors in intraoperative bone cuts and implant alignment. Three homogeneous patient groups undergoing computer assisted TKR were included in the study. Each group was treated by one of three surgeons with varying experience in computer-aided and knee replacement surgery. Surgeon A had extensive experience in knee replacement and computer-assisted surgery. Surgeon B was an experienced knee replacement surgeon. A general orthopaedic surgeon with limited knee replacement surgery experience performed all surgeries in group C. The cutting errors and the number of re-cuts were determined intraoperatively. The complications and mean surgical time were collected for each group. The postoperative frontal femoral component angle, frontal tibial component angle, hip-knee-ankle angle and component slopes were evaluated. The results showed that the number of cutting errors were lowest for TKR performed by the surgeon with experience in navigation. This difference was statistically significant when compared to the general orthopaedic surgeon. A statistically significant superior result was achieved in final mechanical axis alignment for the surgeon experienced in computer-guided surgery compared to the other two groups (179.3 degrees compared to 178.9 degrees and 178.1 degrees ). However, the total number of outliers was similar, with no statistically significant differences among the three surgeons. Experience with navigation significantly reduced the surgical time.

Laboratory and Prosthetic Considerations in Computer-Guided Surgery and Immediate Loading

This article describes the laboratory and the prosthetic steps required for the fabrication of the provisional immediate load prosthesis used in guided surgical treatment protocols. NobelGuide software (Nobel Biocare, Gothenburg, Sweden) was used to fabricate a surgical guide. The surgical guide in turn was used to develop a master model and fabricate the provisional bridge that will be secured to the implants immediately after their placement using the guided surgery template. Using this protocol, the fabrication of the provisional fixed prosthesis for immediate loading patients using the NobelGuide software was possible. The fit of the prosthesis to the implants required minimal adjustment. The patients were able to achieve a comfortable centric occlusion needing only minor adjustments following the securing of the prosthesis to the implants. This protocol allows for the predictable fabrication of provisional immediate load prosthesis.

Technical Innovations and the Evolution of Endoscopic Sinus Surgery

Since the introduction of endoscopic sinus surgery, a number of significant technological advances, as well as an improved understanding of disease pathogenesis and management, have enabled major evolutions in surgical techniques. Modifications to surgical instruments, imaging, the development of the microdebrider, and other newer instrumentation have all contributed to the current level of patient success associated with endoscopic intranasal techniques. At the same time, it has become evident that anatomic variations are less important in the pathogenesis of chronic rhinosinusitis than was previously thought, and that ventilation alone is insufficient to resolve well-established disease. This paper reviews the changes that have occurred in endoscopic sinus surgery over the past 20 years since the techniques were first introduced into the United States, and the technologies that have enabled these changes and the development of extended endoscopic techniques. Continuing developments of interactive computer-guided surgery, endoscopic 3-dimensional imagery, robotics, and improved adjunctive therapies will further extend the role of endoscopic transnasal approaches to an expanded number of skull base and intracranial lesions.

Computer-Guided Surgery Utilizing a Computer-Milled Surgical Template

Computer-Guided Surgery Utilizing a Computer-Milled Surgical Template

A new fast and unsynchronized method for MRI of viscoelastic properties of soft tissues.

Quantitative measurement of mechanical properties of biologic tissues may have several applications for diagnosis or biomechanic modeling in sports medicine, traumatology, or computer-guided surgery. The magnetic resonance imaging (MRI) methods previously tested for these applications all required synchronization between MRI acquisition pulses and the mechanical stimulation. A new unsynchronized method operating with no prior knowledge of intensity, direction, and frequency of the mechanical waves is proposed. A specifically modified SPAMM (SPAtial Modulation of Magnetization) sequence has been used, operating on a 0.2-T MRI system. The experimental results obtained on test objects fit well with theoretical calculations. The new proposed method is very fast (a less than 5-second acquisition time) for routine clinical use.

Computer-guided surgery of the base of the skull

Computer-guided surgery of the base of the skull

Computer-guided surgery for tacfayarrhythmias in children: Current results and expectations

Objectives. The purpose of this report is to summarize our entire surgical experience in the treatment of tachyarrhythmias in children. We emphasize our application of a newer computerized mapping system for use in both the electrophysiology laboratory and the operating room to localize points of activation of the tachyarrhythmias.Background. A retrospective review was undertaken to examine the results of operative procedures in 290 children undergoing surgical treatment for tachyarrhythmias from 1977 to the present.Methods. Operative procedures were performed in 290 children and consisted of the following: surgical ablation of accessory pathways of the Kent bundle type (210 children); surgery with cryoablation for atrial ectopic tachycardia (35 children); surgical excision or cryoablation, or both, for ventricular tachycardia (26 children); cryoablation for the permanent form of junctional reciprocating tachycardia (15 children) and atrioventricular (AV) node reentrant tachycardia (4 children).Results. The surgical cure rate for accessory pathway tachycardia in the era before computerized mapping was 80% (41 patients) in the period from 1977 to 1982 and 95% (86 patients) in the period from 1982 to 1988. This rate improved to 100% (83 patients) after the advent of the computerized mapping technique. These improved results are probably due to a combination of factors, including increasing experience in electrophysiologic mapping and surgery, and cannot be attributed to the computerized mapping system alone. Surgical cure or major improvement in symptoms was documented in 33 (94%) of 35 patents with atrial ectopic tachycardia. Surgical cure was accomplished in 25 (96%) of 26 patients with the complex form of ventricular tachycardia, In 19 patients with the permanent form of junctional reciprocating tachycardia and the more typical AV node reentrant tachycardia, the surgical cure rate was 100%.Conclusions. In all forms of supraventricular reentrant tachycardia that occur in children, preoperative computerized mapping techniques combined with intraoperative computerized mapping and surgical ablation can eliminate tachycardia at a success rate of close to 100%. Computerised mapping techniques are less accurate in patients with atrial ectopic tachycardia because of multiple foci and a broader surface area to be mapped. This experience demonstrates that excellent results can be achieved in the surgical treatment of tachyarrhythmias in children.

The structural-functional elements of normal occlusion

The aim of the present study was to conduct a critical literature review about the treatment concepts of computer-guided surgery in implantology to highlight indication about major advantages and complications of the technique.The literature review was based on Medline database from 2007 to 2012 using the key words “computer-guided implant surgery” for studies written in English. For inclusion, publications had to meet pre-established criteria. Three reviewers independently selected 42 full text articles. The publications included: 18 clinical evaluations, 10 technical notes, 8 clinical reports, and 6 reviews.The scientific evidence available suggests that guided placement has at least as good implant survival as conventional protocols. However several unexpected procedure-linked adverse events during guided implant placement indicate that the clinical demands on the surgeon were no less than those during conventional placement.