Use of long implants with distal anchorage in the skull base for treatment of extreme maxillary atrophy : the remote bone anchorage concept

The objectives of this study are to present a new concept of the bone anchorage using long implants in remote bone sites and to discuss four cases treated with this method. Our patients were treated with long implants with a distant anchorage in the skull bone. The planning procedure, the construction of the drill guide, and the surgical protocol are described. In the clinical cases described, all four patients were rehabilitated with the remote bone anchorage concept using long implants anchored in the skull base. Patients were followed for 5 - 12 years and the implants remained present and stable in these time periods. The skull base implant is a new concept of bone anchorage using long implants. It can be a solution for complicated clinical situations (often failed bone reconstructions and implant placements) or an alternative for bone grafting and maxillary augmentation procedures. There is effective implant retention in the skull base, an anatomical area that is often overlooked for implant placement

Software applied to oral implantology : update

Software in combination with imaging techniques is used increasingly for diagnosis, planning and treatment in oral implantology. Computer-aided surgery allows a great accuracy in implant positioning to be obtained, taking advantage of the amount of bone available and facilitating minimally invasive surgery. It is a significant aid in determining implant number, location, angle and characteristics. A CT with a radiographic template positioned in the mouth is made for the patient. Data are stored on a CD in DICOM 3 format and then introduced in the computer where implant treatment will be planned, using the chosen software. Navigation improves surgical accuracy through the aid of software based on the images captured from CT or MRI and a surgical instrument tracking system. Infrared light-emitting diodes are connected to rotatory instruments and to the patient?s template. Information is collected by special-purpose cameras, allowing the procedure to be viewed in real time on a monitor. It is useful in situations where an exact implantation is demanded, such as anatomical limitations, little space, atrophic maxillae, sinus lifts or zygomatic implants. Articles reviewed agree in emphasizing the reliability and accuracy of the planning and computer-assisted navigation systems available in the market. Nevertheless, many applications are still in the development phase

Rehabilitation of atrophic maxilla: a review of 101 zygomatic implants

Introduction: Zygomatic implants are a good rehabilitation alternative for upper maxilla with severe bone reabsorption. These implants reduce the need for onlay-type bone grafting in the posterior sectors and for maxillary sinus lift procedures - limiting the use of bone grafts to the anterior zone of the upper jaw in those cases where grafting is considered necessary. Objective: To evaluate the survival of 101 zygomatic implants placed in upper maxilla presenting important bone reabsorption, with a follow-up of 1-72 months. Patients and methods: A retrospective study was made of 101 Zygoma® implants (Nobel Biocare, Göteborg, Sweden) placed in 54 patients with totally edentulous and atrophic upper maxilla, in the period between 1998-2004. There were 35 women and 19 men, subjected to rehabilitation in the form of fixed prostheses and overdentures using 1-2 zygomatic implants and 2-7 implants in the anterior maxillary zone. The principal study variables were smoking, a history of sinusitis, the degree of bone reabsorption, and peri-implant bone loss, among others. Results: The descriptive analysis of the 101 zygomatic implants placed in 54 patients with a mean age of 56 years (range 38-75) yielded a percentage survival of 96.04%, with four failed implants that were removed (two before and two after prosthetic loading). Nine patients were smokers, and none of the 54 subjects reported a history of sinus disorders. Discussion and conclusions: Zygomatic implants are designed for use in compromised upper maxilla. They allow the clinician to shorten the treatment time, affording an interesting alternative for fixed prosthetic rehabilitation. This study confirms that zygomatic bone offers predictable anchorage and acceptable support function for prostheses in atrophic jaws. However, these implants are not without complications. Longer-term evaluations are needed of zygomatic implant survival in order to establish a correct clinical prognosi

Zygomatic Implant: State of the Art

Introduction: In the dental implant scenario, the rehabilitation of the maxilla severely reabsorbed with endosseous implants remains a challenge. There are less aggressive alternatives, including short implants, inclined implants, and especially zygomatic (ZI) implants. In cases where the height and width of the residual bone do not allow the placement of conventional dental implants, the ZI can be considered. Objective: Conducted a concise systematic review to analyze the main literary findings on the use of the zygomatic implant as an important alternative for a dental implant, to present the state of the art to the dental community. Methods: The present study followed a concise systematic review model. The search was carried out in the PubMed, Embase, Ovid, Cochrane Library, Web Of Science, and Scopus databases. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results and Conclusion: Zygomatic implants appear to be a consolidated therapeutic option for significantly atrophic maxilla, offering a promising alternative to costly heavy bone graft techniques, fewer complications, less time for rehabilitation, less required prosthodontic work, and significantly higher survival rates. Thus, the zygomatic implant is revolutionizing the implant procedure in the posterior atrophic maxilla, eliminating the complications of bone augmentation and sinus elevation, with delayed healing, showing better clinical results compared to the bone graft, pointing to a possible gold standard for a dental implant

Evaluation of Survival Rate of Zygomatic Implants Placed using Immediate Loading Protocol in Atrophic Maxillaa: A Clinical study

BACKGROUND: Zygoma implants are evidence –based surgical and prosthetic solution for rehabilitation of atrophic posterior maxilla with both classical two stage and immediate loading protocols. Zygoma implants avoid grafting and sinus lift procedures and therefore contribute to a shorter and more comfortable treatment. Zygoma bone is superior to that of the posterior maxilla in providing anchorage and success of zygomatic implant is due to Quad cortical stabilization, that he implant body engages four cortical bones: 1. Maxillary Lingual Plate, 2. Maxillary sinus floor, 3. Maxillary sinus roof, 4. Lateral cortex of the body of zygomatic bone. Immediate loading decreases the time of treatment and increases the acceptance of the treatment by the patient. AIMS AND OBJECTIVES: To evaluate the survival rate of immediately loaded zygomatic implant based on clinical criteria. MATERIALS AND METHODS: 5 patients with completely edentulous atrophic posterior maxilla fulfilling the criteria were selected. Nobel Biocare zygomatic implants were placed in the posterior region of completely edentulous maxilla and anterior conventional implants in selected subjects. The patients were assessed pre operatively and post operatively 1 week, 3 months 6, 9 and 12 months to assess clinical parameters like pain, infect ion, implant stability quotient, Lund – Mackay rhino sinusitis analysis, Ainamo and Bay gingival bleeding index and evaluation of position of apical third of zygomatic implant. The data collected was analyzed statistically. RESULTS: The zygomatic implants and the anterior conventional implants were immediately loaded and a survival rate of 100% was obtained in both zygoma and conventional implants in the current study. The mean ISQ achieved on the right side was 68.80 ± 4.14 and on the left side 65.6 intra operatively which was suggestive of good primary stability. Post operatively after a period of one year follow up the mean ISQ o the right and left side was 71 which indicate secondary stability. CONCLUS ION: Completely edentulous atrophic maxilla rehabilitated with immediate loaded zygomatic implants in combination with anterior conventional implants revealed a survival rate of 100% in one year follow up in current study. There were no potential complications encountered during the follow up period

Dynamic navigation for zygomatic implant placement: a randomized clinical study comparing the flapless versus the conventional approach

Objectives: The assessment of the accuracy of flapless placement of zygomatic implants in edentulous maxilla using dynamic navigation. Methods: A randomized controlled trial was carried out on 20 patients. Patients were randomized into two groups, the flapless (Group 1; n=10) and the conventional (Group 2; n=10). In each case two zygomatic implants were inserted under local anaesthesia, one on the right and one on the left side guided by a dynamic navigation system. The surgical procedure was identical in the two groups except for the reflection of the mucoperiosteal flap which was eliminated in the flapless cases. Postoperative CBCT scans were used to assess the accuracy of the placement of zygomatic implants. Results: Osseointegration was achieved for all the implants except one case in the flapless group, it was successfully replaced after 4 months. Statistically significant accuracy in the position of the zygomatic implants in the flapless group when compared to the conventional one, this was measured at the apex and the entry points of the implants (p < 0.01). The average error of apical deviation was about 5mm, 3mm shift of the coronal entry point, angular deviation was 6 degrees, and 2mm vertical apical disparity was detected between the planned and the achieved surgical position. Perforation of the Schneiderian membrane was noted in three cases, one in flapless group and two in the conventional group. Conclusions: Flapless placement of zygomatic implants guided by dynamic navigation offered satisfactory safety and accuracy. Clinical Significance: This is the first clinical trial to prove the feasibility and accuracy of flapless placement of zygomatic implant with minimal morbidity. The study highlights the innovative reflection of the Schneiderian membrane under guided surgical navigation. The procedure can be performed under local anaesthesia which offers clinical and financial advantages. Adequate training on the use of dynamic navigation is mandatory before its use in clinical cases

Evaluation of Extra maxillary approach of the placement of Zygomatic implants in ZAGA-4 patients using the Zygomatic success code: A Case Series

BACK GROUND: Conventional implants cannot be placed in severely resorbed edentulous maxilla. Extensive pneumatisation of the maxillary sinus may also affect the success of the sinus lift procedures making implant placement and rehabilitation difficult. Zygomatic implants have been used as an alternative to obviate the need for extensive grafting procedures. The extra-maxillary approach is considered a relatively less morbid procedure and has been advocated in the case of severely resorbed maxillae with pronounced buccal concavities (ZAGA-4). The aim of the study is to evaluate extra maxillary approach in severely resorbed edentulous maxillary arch with pronounced buccal concavities (ZAGA 4) using the zygomatic success code MATERIALS AND METHODS: 10 Zygomatic Implants were placed using the extra-maxillary approach in patients classified as ZAGA-IV. All the ten implants placed were evaluated 12 months post-operatively; using the zygomatic success code. RESULTS: The survival rate of all the ten zygomatic implants placed was 100%. When the zygomatic success code was used to evaluate the zygomatic implants, none of the implants was associated with pain and mobility (ZSC mean is 1), none of the implants had sinus associated pathology (ZSC mean is 1), the peri-implant soft tissue recession was observed in two out of ten implants (ZSC mean is 1.9) and all the ten implants had no unfavourable prosthetic offset (ZSC mean is1). CONCLUSION: The extra maxillary approach was effective for successful placement and rehabilitation of severely resorbed maxilla (ZAGA-4) using zygomatic implants with cumulative survival rate of 100% and good zygomatic success code results

Image-guided surgery and medical robotics in the cranial area

Surgery in the cranial area includes complex anatomic situations with high-risk structures and high demands for functional and aesthetic results. Conventional surgery requires that the surgeon transfers complex anatomic and surgical planning information, using spatial sense and experience. The surgical procedure depends entirely on the manual skills of the operator. The development of image-guided surgery provides new revolutionary opportunities by integrating presurgical 3D imaging and intraoperative manipulation. Augmented reality, mechatronic surgical tools, and medical robotics may continue to progress in surgical instrumentation, and ultimately, surgical care. The aim of this article is to review and discuss state-of-the-art surgical navigation and medical robotics, image-to-patient registration, aspects of accuracy, and clinical applications for surgery in the cranial area