Placement Of Zygomatic Implants Research Articles

Importance of Assessing the Position of the Infraorbital Foramen in Quad Zygoma or Unilateral Double Zygoma Implant Surgery.

Evaluate the frequency of occurrence of extreme inferior positioning of the Infraorbital foramen from the infra-orbital rim that can potentially interfere with the placement of Quad or Unilateral Double Zygomatic implants. CBCT scans of 60 patients were read to identify the Infraorbital foramen (IOF)and Infra-orbital rim (IOR). The distances between the two were measured. In cases with increased values, virtual surgical planning was done to evaluate whether two Zygoma implants could be placed in one zygomatic bone. Two out of the 60 cases showed a more inferior location of the IOF, reducing the amount of bone available , thus rendering quad zygoma or unilateral; double zygomatic implants infeasible. Measurement of the distance of the IOF from the IOR is an important step worth incorporating in Quad Zygoma or unilateral double zygoma implant surgery planning.

The use of the Transnasal implant associated with the zygomatic implants in the treatment of atrophic maxilla: A Case Report

Introduction: Rehabilitation of atrophic maxillae can be a real challenge, even for experienced surgeons. The search for faster and less morbid treatments, with the possibility of immediate loading, has led surgeons to apply bone anchoring techniques, with longer implants, anchored in areas further away from the alveolar ridge. Objective: The objective of this article is to describe a case report of rehabilitation of atrophic maxilla with Transnasal and Zygomatic implants. Case report: Female patient, 70 years old, with severe bone resorption that made rehabilitation with conventional dental implants impracticable. Through virtual planning, adequate conditions were found for the placement of zygomatic implants on the left side, but the right side had insufficient bone availability. The rehabilitation was performed with 3 zygomatic implants and 1 transnasal implant. A definitive acrylic prosthesis was installed 5 days after surgery. The patient has 13 months of follow-up without peri-implant alterations, with the implants osseointegrated and her dental occlusion reestablished. Conclusion: The Transnasal Implant may be an auxiliary option for the total rehabilitation of the atrophic maxilla. Virtual planning with computed tomography is essential to guarantee the success of the technique and reduce the chances of problems related to the installation of transnasal implants.

The precision of drill calibration for dynamic navigation

ObjectivesTo quantify the reproducibility of the drill calibration process in dynamic navigation guided placement of dental implants and to identify the human factors that could affect the precision of this process in order to improve the overall implant placement accuracy. MethodsA set of six drills and four implants were calibrated by three operators following the standard calibration process of NaviDent® (ClaroNav Inc.). The reproducibility of the position of each tip of a drill or implant was calculated in relation to the pre-planned implants’ entry and apex positions. Intra- and inter-operator reliabilities were reported. The effects of the drill length and shape on the reproducibility of the calibration process were also investigated. The outcome measures for reproducibility were expressed in terms of variability range, average and maximum deviations from the mean distance. ResultsA satisfactory inter-rater reproducibility was noted. The precision of the calibration of the tip position in terms of variability range was between 0.3 and 3.7 mm. We noted a tendency towards a higher precision of the calibration process with longer drills. More calibration errors were observed when calibrating long zygomatic implants with non-locking adapters than with pointed drills. Flexible long-pointed drills had low calibration precision that was comparable to the non-flexible short-pointed drills. ConclusionThe clinicians should be aware of the calibration error associated with the dynamic navigation placement of dental and zygomatic implants. This should be taken in consideration especially for long implants, short drills, and long drills that have some degree of flexibility. Clinical significanceDynamic navigation procedures are associated with an inherent drill calibration error. The manual stability during the calibration process is crucial in minimising this error. In addition, the clinician must never ignore the prescribed accuracy checking procedures after each calibration process.

Guided placement of zygomatic implants in head and neck cancer patients: implant survival and patient outcomes at 1–3 years of follow-up

Zygomatic implants (ZI) are a valuable option for supporting an obturator prosthesis after maxillary resection. This study was performed to assess the clinical outcomes of a digitally validated guided technique for ZI placement, followed by immediate prosthetic obturation. The primary objective was to evaluate implant survival, while the secondary objective was to assess patient-reported quality of life post-rehabilitation. Twelve patients treated for head and neck cancer received a total of 36 ZI after ablative surgery. The mean duration of ZI follow-up was 30.1 months. The survival rate of ZI placed in non-irradiated patients was 100%, while it was 85% in irradiated patients. Patient-reported outcomes were evaluated using the Liverpool Oral Rehabilitation Questionnaire (LORQv3) and the University of Washington Quality of Life Questionnaire (UW-QOL v4). Most patients reported satisfactory outcomes in the oral function domain of the LORQv3 (mean score 17.7 ± 4.5; possible range 12–48, with lower scores indicating better outcomes). Regarding the UW-QOL v4, the swallowing and chewing domains had the highest scores (mean 97.5 ± 8.7 and 95.8 ± 14.4, respectively; maximum possible score of 100). In conclusion, this treatment approach improves function and quality of life after maxillary ablative surgery. However, irradiated patients showed a noticeable trend of higher implant failure, and this was influenced by tumour position and size impacting the radiation dose to the zygomatic bone.

ZAGA Double Pedicle Palatal Flap for Soft Tissue Management in Zygomatic Surgery.

Oral rehabilitation of the atrophic maxilla using prostheses anchored on zygomatic implants is a well-documented process. To prevent the risk of sinusitis and or oro-antral communications, the placement of zygomatic implants with an externalized path has been proposed. In these cases where the sealing of the implant neck depends exclusively on a hemidesmosomal junction, there is a risk of dehiscence of the soft tissue. This can lead to esthetic problems, bone resorption, oro antral communication, cellulitis, and even orbital infection. To avoid soft tissue recession when implants are placed in a buccal position to the remaining ridge, different procedures have been proposed, the simplest being a good buccal coverage of the implant by keratinized tissue. In this technical note, we propose the use of a double pedicle palatal flap to increase the keratinized tissue buccal to the implant and, at the same time, to facilitate the incision closure by initial intention.

A novel approach for the placement of zygomatic implants: the zygomatic bone zone index

This article explores the considerations and factors that implant dentists may use to decide whether the placement of zygomatic implants is necessary, and if so, the potential considerations in planning for them within the zygomatic bone. A novel treatment planning tool has been presented, the Zygomatic Bone Zone index, to improve the surgical placement of zygomatic implants, to help reduce complications and to allow for further placement within the zygomatic bone in the future. CPD/Clinical Relevance: It is important for clinicians to be aware of treatment modalities that might be of benefit to some patients.

Feasibility and accuracy of a task-autonomous robot for zygomatic implant placement

Zygomatic implants (ZIs) should be placed accurately as planned preoperatively to minimize complications and maximize the use of the remaining bone. Current digital techniques such as static guides and dynamic navigation are affected by human error; therefore, new techniques are required to improve the accuracy of ZI placement. The purpose of this clinical study was to assess the feasibility and accuracy of a task-autonomous robot for ZI placement. Patients indicated for ZI placement were enrolled, and an appropriate surgical positioning piece was selected based on the presence of natural teeth in the maxilla. Preoperative cone beam computed tomography (CBCT) scanning was performed with the surgical positioning piece, and virtual implant design and socket preparation procedures were initiated. Implant socket preparation and placement were automatically performed by the robot according to the preoperative plan under the supervision of the surgeon. Postoperative CBCT scanning was performed to evaluate deviations between the virtual and actual implants. All quantitative data were expressed as standardized descriptive statistics (mean, standard deviation, minimum, maximum, and 95% confidence interval [CI]). The Shapiro-Wilk test was used to assess the normal distribution of all variables (α=.05). Six participants were enrolled, and 8 ZIs were inserted. No intraoperative or postoperative complications were observed. Robotic ZI placement showed a global coronal deviation of 0.97mm (95% CI: 0.55 to 1.39 mm), a global apical deviation of 1.27mm (95% CI: 0.71 to 1.83 mm), and an angular deviation of 1.48 degrees (95% CI: 0.97 to 2.00 degrees). Task-autonomous robots can be used for ZI placement with satisfactory accuracy. Robotic ZI surgery can be an alternative to static guidance and dynamic navigation to improve the accuracy of implant placement.

Technique-Related Survival Rate and Complications of Zygomatic Implant Placement: A Systematic Review and Meta-Analysis.

To assess the survival rate (SR) and probability of postoperative complications at both the implant and patient level for each of the four surgical techniques for zygomatic implant (ZI) placement: Brånemark, sinus slot, extrasinus, and extramaxillary. A systematic literature review and meta-analysis of clinical studies that reported the survival rate and postoperative ZI complications for the rehabilitation of atrophic edentulous maxillae was conducted based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) recommendations. Two independent reviewers consulted four databases during the literature search: MEDLINE (PubMed), Google Scholar, Clinicaltrials.gov, and LILACS. Duplicate articles were eliminated. A total of 35 studies were included in the meta-analysis. Subgroup analysis showed that study design (prospective vs retrospective) had no significant impact (P = .10) on the outcomes. The SR was highest for the Brånemark and extrasinus techniques (100%) and lowest for the sinus slot technique (94%; 95% CI = 86% to 102%). The extramaxillary (38%; 95% CI = 1% to 3%) and the Brånemark (29%; 95% CI = 15% to 44%) techniques resulted in the highest occurrence of patient-level complications. Moreover, the extramaxillary technique showed the highest percentage of prothesis-related complications (44%; 95% CI = 27% to 62%). ZI placement was demonstrated to be a reliable technique for the rehabilitation of severely atrophic maxillae, irrespective of the surgical technique evaluated. Accurate case and surgical protocol selection is of paramount importance to reduce technique-related postoperative complications.

The Accuracy of Zygomatic Implant Placement Assisted by Dynamic Computer-Aided Surgery: A Systematic Review and Meta-Analysis.

The present systematic review aimed to investigate the accuracy of zygomatic implant (ZI) placement using dynamic computer-aided surgery (d-CAIS), static computer-aided surgery (s-CAIS), and a free-hand approach in patients with severe atrophic edentulous maxilla and/or deficient maxilla. Electronic and manual literature searches until May 2023 were performed in the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases. Clinical trials and cadaver studies were selected. The primary outcome was planned/placed deviation. Secondary outcomes were to evaluate the survival of ZI and surgical complications. Random-effects meta-analyses were conducted and meta-regression was utilized to compare fiducial registration amounts for d-CAIS and the different designs of s-CAIS. A total of 14 studies with 511 ZIs were included (Nobel Biocare: 274, Southern Implant: 42, SIN Implant: 16, non-mentioned: 179). The pooled mean ZI deviations from the d-CAIS group were 1.81 mm (95% CI: 1.34-2.29) at the entry point and 2.95 mm (95% CI: 1.66-4.24) at the apex point, and angular deviations were 3.49 degrees (95% CI: 2.04-4.93). The pooled mean ZI deviations from the s-CAIS group were 1.19 mm (95% CI: 0.83-1.54) at the entry point and 1.80 mm (95% CI: 1.10-2.50) at the apex point, and angular deviations were 2.15 degrees (95% CI: 1.43-2.88). The pooled mean ZI deviations from the free-hand group were 2.04 mm (95% CI: 1.69-2.39) at the entry point and 3.23 mm (95% CI: 2.34-4.12) at the apex point, and angular deviations were 4.92 degrees (95% CI: 3.86-5.98). There was strong evidence of differences in the average entry, apex, and angular deviation between the navigation, surgical guide, and free-hand groups (p < 0.01). A significant inverse correlation was observed between the number of fiducial screws and the planned/placed deviation regarding entry, apex, and angular measurements. Using d-CAIS and modified s-CAIS for ZI surgery has shown clinically acceptable outcomes regarding average entry, apex, and angular deviations. The maximal deviation values were predominantly observed in the conventional s-CAIS. Surgeons should be mindful of potential deviations and complications regardless of the decision making in different guide approaches.

The Buccal Fat Pad Technique an Option to Prevent Complications in Zygomatic Implants Surgery: 5 -13 Years Follow Up

Background: The extrasinus approach is a technique, with an implant placement of zygomatic implants with approach outside of the maxillary sinus. The technique reduces the risk of sinusitis and favors prosthetic rehabilitation, but there is a risk of soft tissue recession, exposure of the implant threads and contamination of the implant surface. Purpose: The objective of this retrospective clinical study is to prove and present the benefits of the use of the Buccal Fat pad flap technique and its feasibility in preventing soft tissue complications in rehabilitations with zygomatic implants. Materials and Methods: Patients from authors clinics in Brazil (IDM - Clinic – Rio de Janeiro) and Chile (Universidad de Los Andes – Santiago and Universidad de La Frontera – Temuco) with severe maxillary atrophy rehabilitated by maxillary full fixed prosthesis with zygomatic implants. Were installed two implants one in each side associated to conventional implants and in more critical conditions of bone atrophy, four zygomatic implants, two in each side were used. In cases with risk of an oroantral communication and were used extrasinusal approach (ZAGA concept), the buccal fat pad flap technique was used. The peri-implant soft tissue recession (PISTR) was evaluated by clinical examination and recession was scored on an ordinal scale: I = no recession; II = slight recession (implant head visible); III = recession with up to seven exposed threads. Results: In the period from May 2005 to January 2013, a total of 147 zygomatic implants were installed in 52 patients (Men = 22 and Women = 30) with mean age of 56,9 years old, were submitted to surgery of zygomatic implants. In all cases, the buccal fat pad flap technique was used to prevent complications such as: mucosal resection or frenestration and exposure of the implants or oroantral communication, depending on the positioning of these implants. The patients were followed over the years and in 5 cases (3,4%) there was tissue retraction and exposure of the threads of an implant. Conclusion: It can be concluded that the use of the buccal fat pad flap proved to be a simple and effective technique in the prevention of complications of soft tissue recession associated with the surgery of zygomatic implants installed with the extrasinusal technique.

Three-Dimensional Evaluation of the Accuracy of Zygomatic Implant Placement Through an In-House Fully Guided Approach.

Purpose: To validate guided surgery for zygomatic implants (ZIs) by analyzing the final position of the implants relative to the preoperatively planned position. Material and Methods: Five patients with fully edentulous atrophic maxillae treated with four ZIs through a fully guided implant surgical approach were evaluated. The preoperative phase included digital planning, through which the surgical guide was designed and created. Analysis of the guided surgery accuracy was carried out by superimposing the digital planning over the final position of the implants using preoperative and postoperative CBCT. The radiologic evaluation included implant angular deviation, entrance deviation, exit deviation, platform deviation, and apex apicocoronal and mesiodistal deviation. Results: All five patients (two men and three women; mean age: 61.8 ± 3 years) were each treated with four ZIs using a fully guided approach with an extrasinusal path, obtaining ideal emergence of the implants. Superimposition comparison found a mean axial angular implant deviation of 0.79 ± 0.41 degrees and a mean implant entrance deviation of 0.95 ± 0.26 degrees. The platform deviation was 0.62 ± 0.19 mm buccopalatally and 0.76 ± 0.14 mm mesiodistally, while the apical deviation was 0.42 ± 0.13 mm buccopalatally and 1.06 ± 0.37 mm mesiodistally. Conclusions: Guided surgery in zygomatic implants appears to be sufficiently accurate to make it a safe and predictable technique.

Key clinical considerations and updates on the techniques for successful zygomatic implant: a systematic review

Introduction: In the context of implant dentistry, what represents a great burden in the aesthetic recovery of patients who have suffered dentoalveolar trauma is the lack of bone in the alveolar crest, compromising the quality of life due to tooth loss. Objective: Performed a systematic review to present key clinical considerations and updates on the best techniques for successful zygomatic implantation. Methods:The systematic review rules of the PRISMA Platform were followed. The research was carried out from February to May 2023 in Scopus, PubMed, Science Direct, Scielo, and Google Scholar 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:A total of 128 articles were found, 54 articles were evaluated in full and 34 were included and developed in this systematic review study. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 22 studies with a high risk of bias and 32 studies that did not meet GRADE. Zygomatic implants can be placed with good precision. The application of these newly designed 3D-printed surgical guides results in the predictable placement of zygomatic implants and offers the possibility of immediate prosthetic rehabilitation. Preliminary data from one year after loading suggest that immediately loaded zygomatic implants were associated with statistically significantly fewer prosthetic failures. Also, zygomatic implants proved to be a better rehabilitation modality for severely atrophic jaws.

Application of titanium 3D-printed double-sleeve guide for zygomatic implants: A technique report.

The unique anatomical structure of the atrophic edentulous maxilla limits the placement of endosteal root form dental implants without bone grafting and augmentation. Surgical placement of zygomatic implants in an optimal position remains challenging. This technique report illustrates a novel digital guide technology, including the design workflow, application method, and indications for assisting with the placement of zygomatic implants using a bone-supported titanium double-sleeve guide. In addition, when the implant body reaches the zygomatic bone following an intra-sinus path, including ZAGA type 0 and ZAGA type 1 cases, a matching window osteotomy surgical guide is used to locate the lateral window boundary and protect the sinus membrane. With this technique, the surgical procedure is simplified, and the precision of guided zygomatic implant placement is improved.

Accuracy of Zygomatic Implant Placement Using a Full Digital Planning and Custom-Made Bone-Supported Guide: A Retrospective Observational Cohort Study

The aim of the study was to evaluate the accuracy of zygomatic implant placement using customized bone-supported laser-sintered titanium templates. Pre-surgical computed tomography (CT) scans allowed to develop the ideal virtual planning for each patient. Direct metal laser-sintering was used to create the surgical guides for the implant placement. Post-operative CT scans were taken 6 months after surgery to assess any differences between the planned and placed zygomatic implants. Qualitative and quantitative three-dimensional analyses were performed with the software Slicer3D, recording linear and angular displacements after the surface registration of the planned and placed models of each implant. A total of 59 zygomatic implants were analyzed. Apical displacement showed a mean movement of 0.57 ± 0.49 mm on the X-axis, 1.1 ± 0.6 mm on the Y-axis, and 1.15 ± 0.69 mm on the Z-axis for the anterior implant, with a linear displacement of 0.51 ± 0.51 mm on the X-axis, 1.48 ± 0.9 mm on the Y-axis, and 1.34 ± 0.9 mm on the Z-axis for the posterior implant. The basal displacement showed a mean movement of 0.33 ± 0.25 mm on the X-axis, 0.66 ± 0.47 mm on the Y-axis, and 0.58 ± 0.4 mm on the Z-axis for the anterior implant, with a linear displacement of 0.39 ± 0.43 mm on the X-axis, 0.42 ± 0.35 mm on the Y-axis, and 0.66 ± 0.4 mm on the Z-axis for the posterior implant. The angular displacements recorded significative differences between the anterior implants (yaw: 0.56 ± 0.46°; pitch: 0.52 ± 0.45°; roll: 0.57 ± 0.44°) and posterior implants (yaw: 1.3 ± 0.8°; pitch: 1.3 ± 0.78°; roll: 1.28 ± 1.1°) (p < 0.05). Fully guided surgery showed good accuracy for zygomatic implant placement and it should be considered in the decision-making process.

Minimally Invasive Navigation-Guided Quad Zygomatic Implant Placement: A Comparative In Vitro Study.

Purpose: Zygomatic implants (ZIs) have been considered a reliable alternative treatment for patients with maxillary atrophy and/or maxillary defects. The use of a navigation system for assisting ZI placement could be a reliable approach for enhancing accuracy and safety. The purpose of this in vitro study was to evaluate the accuracy of a new dynamic surgical navigation system with its minimally invasive registration guide for quad zygomatic implant placement in comparison with a gold standard navigation approach. Materials and Methods: A total of 40 zygomatic implants were placed in 10 3D-printed models based on the CBCT scans of edentulous patients. For registration, a surgical registration guide with a quick response plate was used for the test group, and five hemispheric cavities as registered miniscrews in the intraoral area were used for the control group. In each model, a split-mouth approach was employed (two ZIs in bilateral zygomata) to test both systems. After ZI placement, a CBCT scan was performed and merged with pre-interventional planning. The deviations between planned and placed implants were calculated as offset basis, offset apical, and angular deviation and compared between the systems. Results: The offset basis, offset apical, and angular deviation were 1.43 ± 0.55 mm, 1.81 ± 0.68 mm, and 2.32 ± 1.59 degrees in the test group, respectively. For the control group, values of 1.48 ± 0.57 mm, 1.76 ± 0.62 mm, and 2.57 ± 1.51 degrees were measured without significant differences between groups (all P < .05). The accuracy of ZI positions (anterior and posterior) were measured without significant differences between groups. Conclusion: Two navigation systems with different registration techniques seem to achieve comparable acceptable accuracy for dynamic navigation of zygomatic implant placement. With the test group system, additional pre-interventional radiologic imaging and invasive fiducial marker insertion could be avoided.

Comparative analysis of biomechanical response between zygomatic implant and Facco technique through the three-dimensional finite element method.

The placement of zygomatic implants is an alternative used for rehabilitation of edentulous patients with atrophic maxilla. However, the complexity of the various techniques suggested in the literature requires high skill from surgeons. Aim: The objective of this research was to compare the biomechanical performance of traditional technique of zygomatic implant placement in relation to a new proposal, the Facco technique, through finite element analysis. A three-dimensional geometric model of the maxilla was input into computer-aided design software (Rhinoceros version 4.0 SR8). STL file of the geometric models of implants and components supplied by the company Implacil De Bortoli was converted to volumetric solids through reverse engineering by RhinoResurf software (Rhinoceros version 4.0 SR8). Three groups were modeled: traditional technique, Facco technique without frictional contact and Facco technique with frictional contact, following the recommended position in each technique for implant placement. All models received a maxillary bar. Groups were exported to the computer-aided engineering software ANYSYS 19.2, in step format. Mechanical static structural analysis was requested with occlusal load of 120N. All elements were considered isotropic, homogeneous, and linearly elastic. Contacts were considered ideal and system fixation was considered at the bone tissue base. There is similarity between the techniques. Microdeformation values capable of generating undesirable bone resorption were not observed in both techniques. Highest values in the posterior region of Facco technique were computed at the angle of part B close to the posterior implant. Biomechanical behaviors of the two evaluated zygomatic implant techniques are similar. Prosthetic abutment (pilar Z) modifies the distribution of stresses over the zygomatic implant body. Highest stress peak was found in the pilar Z, but it is within acceptable physiological limits. Key words:Atrophic maxilla, zygomatic implants, surgical techniques, pilar Z, dental implants.

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

ObjectivesThe assessment of the accuracy of flapless placement of zygomatic implants in edentulous maxilla using dynamic navigation. MethodsA 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. ResultsOsseointegration was achieved for all the implants, except one case in the flapless group. Statistically significant differences in the accuracy of the position of the zygomatic implants was found between the flapless and the conventional groups, measured at the apex and the entry points of the implants (p < 0.01). The average apical and coronal deviations were 5 mm and 3 mm, respectively; the angular deviation was 6°, and 2 mm 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. ConclusionsFlapless placement of zygomatic implants guided by dynamic navigation offered satisfactory safety and accuracy. Clinical significanceThis 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 advantages. Adequate training on the use of dynamic navigation is mandatory before its use in clinical cases.

Zygomatic implants under local anesthesia: A technical note

The placement of zygomatic implants is a surgical procedure that is most often performed under general anesthesia, due to the duration and the difficulty of the procedure, and in particular due to the necessity of a significant detachment. However, depending on the operator's experience, this procedure can be performed under local anesthesia. Indeed, this variation offers many advantages. It simplifies the procedure, allows the patient's collaboration as well as a radiological control during the operation and reduces the postoperative effects. It also eliminates any risk related to general anesthesia. It is systematically practiced in our activity with a very good acceptance from the patients.

Flapless placement of zygomatic implants using dynamic navigation: an innovative technical note

Zygomatic implants are routinely used for the rehabilitation of the midface and edentulous maxilla; the procedure is carried out under general anaesthesia and requires the direct lifting of the Schneiderian membrane. A prefabricated surgical guide is usually used to direct the position of the zygomatic implants during surgery. This proof-of-concept study explored an innovative flapless approach for placement of zygomatic implants guided by dynamic navigation. Under local anaesthesia eight zygomatic implants were placed using a flapless technique. The preplanned position of zygomatic implants was transferred to the operating theatre using dynamic navigation, which guided the sinus lift procedure and the planned osteotomy. Operative complications were recorded, the accuracy of the implant position was measured and postoperative morbidities including pain and swelling were evaluated. Surgical complications were minimal, the Schneiderian membrane was intact in all the cases except one, which required the application of resorbable collagen membrane. Satisfactory accuracy was achieved regarding the precision of implant position and angulation. One of the patients developed maxillary sinusitis three months following surgery. Postoperative pain and swelling were minimal. The dynamic navigation guided flapless placement of zygomatic implants under local anaesthesia is a feasible technique with minimal surgical complications and postoperative morbidities.

Comparative evaluation of extrasinus versus intrasinus approach for zygomatic implant placement.

Edentulism, a common problem can occur either as a congenital defect or acquired later due to dental caries, periodontitis, as a consequence of aging, maxillofacial trauma or post-ablation in tumor resections. The rehabilitation of the missing teeth can be done using dental implants. To overcome the deficiency of available bone, processes like sinus augmentation with substituted bone graft and Le Fort I osteotomy with interpositional bone graft have been described in the literature. In order to overcome the associated limitations with these procedures, implants were designed that can be placed in specific anatomical areas like zygoma. This study aims to compare two different types of surgical approaches (Intrasinus vs Extrasinus) for the placement of zygomatic implants to treat atrophic maxilla. The placement of zygomatic implant through both extrasinus and intrasinus approaches were evaluated on the basis of different parameters and it was observed that postoperative pain and swelling was significantly found in intra sinus approach as compared to extra sinus approach. However, in the intranasal approach, poor patient compliance or low satisfaction rate was observed as compared to extra sinus approach. On the basis of the results of the study and post operative evaluation based on various criteria, it was concluded that extra sinus approach has got an edge over intra sinus approach.