Navident Case Presentations
“Endodontic Microsurgery of an Anatomically Challenging Zone Using Dynamic Navigation” By Dr Paula Villa, Colombia, 2020
Enhanced magnification and visualization, innovations in instrumentation, new sealing materials and the incorporation of soft and hard tissue augmentation practices have brought Endodontic Microsurgery (EMS) from a last resort procedure to an integral part of endodontic retreatment.1,2 The retreatment of a failing root canal treatment is fraught with potential complications. The removal of cast posts (size and length can potentiate fracture)3 distinguishing bonded fibre posts from the surrounding dentin,4 removal of separated instruments5 negotiating blocked canals,6 circumventing ledging and a myriad of other factors can complicate removal of the residual bio-load and impede resolution of periradicular pathosis.7,8. Where possible, retreatment alone would be the treatment option of choice, however, where retreatment risk factors are high, EMS is the most viable option, far more so now than prior to the transition to microsurgical protocols.
Contemporary EMS protocols provide for minimal flap size, small osteotomies and resections perpendicular to the long axis of the root. These minimally invasive practices reduce morbidity, accentuate more rapid healing, minimize the size of the retro-preparation and the number of dentinal tubuli exposed.9 Magnification and illumination have lessened the risk of damage to anatomic structures such as the IAN, maxillary sinus and the greater palatine nerve and artery. Given the inability to visualize the surgical site in three-dimensions, the possibility of procedural error remains, thus impacting on treatment options.10-13
Recently, Dynamic Navigation technology has been used in EMS to guide cutting instruments, including piezotomes, in real time, to perform osteotomies and apicoectomies. Dynamic Navigation systems map the patient’s jaws to their cbCT scan by trace registering landmarks on teeth of the jaw to be treated. The system’s stereoscopic camera recognizes optical markers attached to the jaw to be treated and the instrument to be used and monitors the drill or saw position during the surgery. Unlike static navigation guides, Dynamic Navigation procedures are not constrained to a predetermined path, there is no risk of distortion as a complication of the guide fabrication, and the inability to work in restricted areas of the mouth due to the bulk of the guide is obviated.
Dynamic navigation enables adjustment of the osteotomy pathway and the angle of the root section during the EMS procedure. The clinician follows the surgical instrument’s movement in three-dimensions on the computer monitor and assesses the surgical site through the microscope oculars. This case report presents the use of Dynamic Navigation to avoid damage to the Schneiderian membrane of the maxillary sinus while performing EMS in an anatomically challenging space.
“Dynamic Navigation by Innovative Registration” By Dr Ricardo Henriques, Portugal 2018
3-D implant planning and mapping that plan to the real surgical environment are two important steps in implant rehabilitation.1,2 Misplaced implants can create difficult aesthetics, functional and biological problems and can result in implant loss.3–5
There are three ways to transfer a planned implant’s position into the real patient’s jawbone:
- mental navigation, so-called freehand navigation,
- static navigation using surgical templates,6 and
- dynamic navigation using a stereoscopic camera.7,8
The freehand approach is totally dependent on the surgeons’ experience, skills and mindset during treatment and creates the highest deviations compared to the other approaches.2
The usage of surgical templates provides a higher accuracy compared to freehand surgery, but has a few limitations, such as the inability to modify the plan once the surgical template has been manufactured. Surgical templates require longer drills which can make their use quite difficult or even impossible. Other concerns are irrigation issues and incompatibility with advanced surgical protocols.
Dynamic navigation is, at present, the most effective way to transfer the planned implant’s position to the real patient as it guides the surgeons’ motions using real-time feedback. It is especially useful to reduce flapped procedures with the advantage of improved soft-tissue healing, patient comfort and reduced bone resorption. Dynamic navigation allows planning modifications at any time, even during treatment, and can be used in cases with limited mouth opening or in combination with osseodensification drills.
"Dynamic Navigation for Precise Implantation in Cases of Critical Anatomy" By Dr David Burgess, United Kingdom 2017
Using the CBCT image as a map, dynamic navigation guides surgeons just like a GPS guides drivers. The clinician virtually plans where implants should be placed. During surgery, the navigation system dynamically tracks the drill and the patient’s jaw, providing guidance and visual feedback to ensure the implants are placed according to plan.
There are several advantages with dynamic navigation. The technology allows clinicians to place implants more accurately than free-hand. This results in improved safety and aesthetics, as it helps the clinician to anticipate and to avoid potential complications. Other advantages are the ability to have more minimal invasive treatments, which means less chair time, less patient discomfort and less recovery time. This treatment option has generally been seen as a ‘blind’ procedure in the past, but the ability to avoid delicate anatomical structures due to the real-time surgical feedback makes so-called flapless surgery a valuable option.
In the following case report, Dr David Burgess describes how using computer-guided dynamic navigation helped him overcome clinical challenges for dental implant placement in the lower posterior region.
"Flapless Implant Placement with an Internal Sinus Lift Using Dynamic Guided Navigation" By Naheed Mohamed, DMD 2017
Today implant surgery is focused on being minimally invasive with an emphasis on prosthetically guided implant placement. Implants which are not placed in a prosthetically favorable position are at risk for future complications involving the prosthetic components or peri-implant tissues. Successful implant placement is not only judged by osseointegration but also the esthetics. In a climate where implant therapy is held to the highest of standards; using advanced tools to simplify surgical dental implant placement is a requisite for success.
Currently computer guided surgery involves the use of a CBCT (cone beam computer tomography) scan and possibly an intra-oral scan to allow personalized digital surgical planning. This plan is then transferred to the patient in the form of a surgical guides to aid in accurate implant placement. These guides however are static and do have some drawbacks. They are not always stable depending on whether they are supported by teeth, mucosa, or bone. Limited mouth opening does become an issue when surgical guides are used to place implants for posterior dentition. And lastly if there is any error in the digital planning, segmentation of the anatomy, or data transfer to the guide fabrication, the error is passed down onto the guide’s implant position. If errors are noted during surgery, then the guide becomes essentially useless.
The next evolution in guided dental implant surgery comes from neurosurgery and orthopedic spine surgery where it has been used for quite some time. Claronav Inc has developed a live navigation system using optical tracking cameras (Fig 1) during implant surgery to provide the surgeon with CBCT based real-time three dimensional drill guidance during implant surgery. One of the main advantages of this Navident system (Fig1) is that dynamic navigation allows intra-operative changes to implant position in real time if any errors or anatomical complexities are noted during the surgery. The flexibility of having a guided implant placement in a digitally planned ideal location without the need for a static surgical stent and having the osteotomies live navigated on CBCT data using optical tracking is a game changer for implant dentistry. This open system also has the flexibility of using any implant system and any drill to guide placement. The case presented below showcases the flexibility of real time navigation where Straumann implant drills are used for placement of an implant with a simultaneous internal sinus lift using the Hiossen CAS-KIT drills with the Navident system.
“Dynamic Navigation in Fully Edentulous Maxilla” By Prof. Dr Hakan Uysal & Dr Noyan Basal, Turkey 2017
Preoperative planning is the most important part of a successful implant rehabilitation and requires multiple parameters to be considered for the precise placement of implants. The implants should be placed not only within anatomical boundaries but also be strategically located to support a prosthesis that will fulfil both functional and aesthetic requirements.
3-D virtual images are being used through computer software, which transforms CBCT scans into 3-D virtual models. However, after a precise planning or virtual realisation of the treatment, the osteotomy should also be executed precisely according to the plan and would likely require guidance of the drills and the implant.
For years, stereolithographic static guides have been used successfully for implant osteotomies, using detailed information implemented through 3-D virtual images.1,2 Static guides on the other hand present several disadvantages. The loss of tactile feeling during osteotomy and the fact of being limited to the predesigned drilling trajectory are considered to be their major drawbacks.
"Use of Dynamic Navigation for Dental Implant Surgery" By Dr. Jan D’haese Ghent University March, 2015
Although osseo-integration of dental implants is predictable1, thorough pre-operative planning is a prerequisite for a successful treatment outcome.2Anatomic limitations as well as prosthetic considerations encourage the surgeon to obtain a very precise positioning of the implants. Historically, standard radiographic imaging techniques (intra-oral and panoramic) were available for investigation of potential implant sites. Throughout the years, spiral tomography and computed tomography (CT) were often used as a diagnostic tool.3 These techniques provide a 2-dimensional cross section image of the desired implant location and enables a detailed bucco-lingual view of the dimensions of the jawbone. Nowadays, it is well known that 3-dimensional CT scan based pictures allow a more reliable treatment planning than when only 2-dimensional data are available.4 Transforming the CT scan images into a 3D virtual image can be achieved using computer software packages,5 allowing for a 3D viewing using Computer Aided Design (CAD) technology. For years, stereolithographic guided surgery seemed to be the golden standard in computer guided implant surgery. The technique has been well developed over the last years and several scientific reports have been published regarding accuracy, complications, survival and success6. Real-time navigation seems to be a valuable alternative to stereolithographic (static) guided surgery as it offers the clinician some advantages compared to the former technique. Using real-time (dynamic) navigation one can avoid the fabrication of a stereolithographic template resulting in a less expensive treatment. As navigation is considered as a dynamic guided surgery system, changes to the treatment planning (location and size of the implants, number of the implants, flap or flapless…) can be easily made intra-operatively.