Zygomatic Implants Research Articles

Dynamic navigation and technical improvements in zygomatic surgery

The rehabilitation of the severely atrophied edentulous maxilla poses a great challenge to surgeons and prosthodontics that work on this particular area. The classic approach implies bone augmentation techniques by means of bone grafting, bone distraction techniques, tilted and short implants. All of these require major surgery, sometimes associated with morbidity at donor and receptor sites and functional rehabilitation of the patient must occur in two surgical stages. Since the development of the zygomatic implants by Per-Ingvar Branemark, there’s an alternative to bone grafting techniques, using the body of the zygomatic bone as major point of anchorage to an intraoral osteointegrated implant. This procedure allows the patient to regain orofacial function in only one surgical stage, with high predictability, less morbidity, time spend and costs. In this scientific article the authors present a set of technical improvements in the zygomatic implant (S.I.N. - Implant System, São Paulo, Brazil) in combination with a new dynamic navigation system called StealthStation™ (Medtronic, Dublin, Irland) used for the first time in this type of surgery.

Fully Guided Zygomatic Implant Surgery.

Rehabilitating a severely atrophic maxilla is a complex procedure. In case of severe resorption, zygomatic implants are indicated and loading of the implants at the end of the surgery is desirable. We present a new method by means of guided surgery for the placement of zygomatic implants, using specially designed metal templates that should be supported by bone. The treatment planning for completely guided prosthetic rehabilitation of the maxilla with zygomatic implants was digitally performed. A radiographic template was designed for the prosthetic treatment planning. A surgical template was used to replicate the digitally planned steps in vivo. The procedure ended with the positioning of a custom-made temporary prosthesis. This method can reduce the surgery duration, simplify the procedure, and optimize the outcome. It requires equal cooperation among technicians, prosthodontists, and surgeons. Nineteen out of twenty patients included in the study presented successful implants and prosthesis at the moment of analysis. The present approach addressed the needs for zygomatic-implant surgery. The surgical and prosthetic plan, position, emergence, the shape of the implants, the position of the temporary prosthesis, the inter-arch relationships, and surgical templates were designed in a completely virtual environment and performed by the surgeon on stereolithographic models beforehand. Consequently, the surgical procedure was considerably simplified.

Accuracy of digital planning in zygomatic implants

BackgroundZygomatic implants have been described as a therapeutic alternative for patients with severe maxillary atrophy in order to avoid bone augmentation procedures. Taking that into account, in these treatments, the key factor is the position of the implant, the virtual surgical planning (VSP) is widespread among most clinicians before surgery on the patient. However, there are no studies which evaluate the clinical relevance of these VSP.The aim of this study is to determine whether digital planning on zygomatic implants has any influence on the implant dimensions and position, even when performing conventional surgery afterwards.ResultsFourteen zygomatic implants were placed in four patients. Pre-operative and post-operative helicoidal computed tomography were performed to each patient to allow the comparison between the digital planning and the final position of implants. Tridimensional deviation (TD), mesio-distal deviation (MDD), bucco-palatine deviation (BPD), and apico-coronal deviation (ACD) were evaluated as well as angular deviation (AD). Significative differences in apical TD were observed with a mean of 6.114 ± 4.28 mm (p < 0.05). Regarding implant position, only implants placed in the area of the first right molar reported significant differences (p < 0.05) for ACD. Also, implant length larger than 45 mm showed BPD significative differences (p < 0.05).ConclusionsZygomatic implant surgery is a complex surgical procedure, and although VSP is a useful tool which helps the clinician determine the number and the length of zygomatic implants as well as its proper position, surgical experience is still mandatory.

Evaluation of zygomatic bone region for placement of quad zygomatic implants using CBCT in postmenopausal women

Insufficient height and width of the alveolar ridge at the implant site remains with inadequate bone volume following extraction in older age people especially in postmenopausal women. Postmenopausal women are susceptible to primary osteoporosis where more bone resorption than formation is seen resulting in decreased bone mass. Hence the present study aims to evaluate the zygomatic bone region for placement of quad zygomatic implants using CBCT.: A total of 120 CBCT images of female patients who were between the age group of 45 yrs to 65 yrs were taken. The zygomatic bone was evaluated for pneumatisation zones and thickness of zygomatic bone at three different regions i.e., superior, middle and inferior at nine points on zygoma bone along with bone to implant contact (BIC) region using virtual software. The largest thickness in the superior, middle and inferior regions were at Point A2(8.01+/-2.10 mm), Point B2 (7.01+/-1.62 mm), and Point C1 (6.65+/-1.64 mm), respectively. The virtually placed implants at Point A3 (15.92+/-4.16 mm) and Point B2 (12.02+/-3.62 mm) had the highest BICs. : To obtain the largest BICs, results suggested that the posterosuperior region (Point A3) and the centre of zygoma (Point B1) were the optimal places for the placement of quad zygomatic implants.

Identification of the Pathway and Appropriate Use of Four Zygomatic Implants in the Atrophic Maxilla: A Cross-Sectional Study.

This cross-sectional study aimed to identify and characterize the pathway for appropriate placement of four zygomatic implants in the severely atrophic maxilla and to group the anatomical variations of the osteotomy trajectory for anterior zygomatic implants. CBCT images of patients presenting indications for the use of four zygomatic implants to withstand a maxillary rehabilitation were reviewed. Cross-sectional planes corresponding to the implant trajectories, designed according to a zygoma anatomy-guided approach for implants placed in the anterior and posterior maxilla, were assessed separately. The relationship of the implant osteotomy trajectory with the correlated residual alveolar bone, nasal and sinus cavities, maxillary wall, and zygomatic bone anatomies was established. The study population included 122 globally recruited patients, with 488 zygomatic implants, 244 of which had their starting point on the anterior incisor-canine area and 244 on the posterior premolar-molar area. The anatomy of the osteotomy path designed for the anterior implants ("A") was named and grouped into five assemblies from zygomatic anatomy-guided ZAGA A-0 to A-4, representing 2.9%, 4.5%, 19.7%, 55.7%, and 17.2% of the studied sites. Percentages for posterior implant ("P") trajectories of the osteotomy were grouped and named as ZAGA P-0 to P-4, representing 5.7%, 10.2%, 8.2%, 18.4%, and 57.4% of the sites, respectively. Approximately 70% of the population presented anatomical intra-individual differences. The trajectory of the zygomatic implant followed different anatomical pathways depending on its coronal point being anteriorly or posteriorly located, which justifies a new zygoma anatomy-guided approach classification for anteriorly placed zygomatic implants. Topographic characteristics of the anatomical structures that are cut by an anterior oblique plane joining the lateral incisor-canine area to the zygomatic bone, representing the planned anterior osteotomy path in a quadruple-zygoma indication, have not been previously reported. Adaptation of surgical procedures and implant sections/designs to individual patients' anatomical characteristics is essential to reduce early and long-term complications.

Clinical outcomes and biological and mechanical complications of immediate fixed prostheses supported by zygomatic implants: A retrospective analysis from a prospective clinical study with up to 11 years of follow-up.

Zygomatic implants alone or in combination with conventional implants have been used for severe atrophic maxillary arches. Long-term outcomes of extramaxillary technique need validations. To retrospectively assess the clinical outcomes and the prevalence of surgical, biological, and prosthetic complications of implant-fixed complete dental prostheses (IFCDPs) supported by zygomatic implants up to 11 years of follow-up. Dental records of 34 subjects treated between October 2008 and June 2019 were reviewed. Patients received an immediate fixed full-arch prosthesis supported solely by zygomatic implants or by a combination of zygomatic and conventional implants. A total of 90 zygomatic implants and 53 standard implants were placed. Up to 11 years of follow-up, two conventional implants were lost, leading to 96.2% success rate for conventional implants and 100% for zygomatic implants. Marginal bone loss for conventional implants averaged 0.85 ± 0.17 mm after the first year and 1.36± 0.12 mm after 10 years, resulting in full implant success. No prosthesis was lost. The main surgical complication was the perforations of the Schneiderian membrane, occurring in five patients and in seven sinus cavities. Considering the biological complications, mucositis for standard and zygomatic implants ranged between 21%-35% and 26%-40%, respectively. No peri-implantitis were reported. Soft tissue hypertrophy ranged between 1.8% and 30% for conventional implants and 1.1%-35% for zygomatic implants. Inflammation under the prosthesis ranged between 33% and 50%. For the mechanical complications, abutment loosening was recorded in 5.8% of cases (two patients), tooth debonding and fracture of the prosthesis happened in five subjects (14.7%), and loosening of the prosthetic screws was reported in one patient (2.9%). Immediate rehabilitation of the severely atrophic maxilla with zygomatic implants alone or in combination with standard implants could be considered a viable treatment modality.

Factors influencing implant and prosthesis survival in zygomatic implant-supported fixed rehabilitation: a retrospective study.

The aim of this retrospective study was to evaluate mid-term implant and prosthesis survival in patients with edentulous atrophic maxillae submitted to zygomatic implant-supported fixed rehabilitation and to identify possible related risk factors. Data were collected from records of patients with edentulous atrophic maxillae, in good general health and who were rehabilitated by means of acrylic resin full-arch screw-retained prosthesis supported by at least one zygomatic implant, between the years of 2006-2017. Implant and prosthesis survival rates were calculated. The association between implant and prosthesis loss and quantitative and qualitative variables of interest was verified with t tests and Fisher's exact tests, respectively. For the significant variables in the latter, odds ratio and 95% confidence intervals were additionally calculated. The sample comprised 66 patients in whom 171 zygomatic implants were placed to support maxillary screw-retained full-arch prostheses. Implant and prosthesis survival rates of 94.15% and 92.4%, respectively, were observed in a mean of 3.6years of follow-up (up to 11.7years). Implant loss was 4.33 more likely to occur when adverse events were recorded after the procedure of implant placement (P = 0.026) and 10.31 more likely to occur in implants that had their prosthesis repaired during follow-up visits (P = 0.004). Prosthesis loss was 22.00 times more likely to occur when implants were previously lost (P < 0.001). All prostheses that were considered as failures (i.e. were replaced) had been previously submitted to laboratory repair at some point during follow-up. Zygomatic implant rehabilitation demonstrated to be a reliable method with good mid-term results. The occurrence of post-surgical adverse events and need for laboratory repair of the prosthesis were found to be significant risk factors for implant loss. Previous implant loss was significantly associated with prosthesis loss. These risk factors may be prevented by means of detailed planning of the rehabilitation to be carried out, including post-operative care of the patients, so that treatment success using zygomatic implants can be achieved.

Immediate implant-retained prosthetic obturation after maxillectomy based on zygomatic implant placement by 3D-guided surgery: a cadaver study

BackgroundThe aim of this study was to introduce a complete 3D workflow for immediate implant retained prosthetic rehabilitation following maxillectomy in cancer surgery. The workflow consists of a 3D virtual surgical planning for tumor resection, zygomatic implant placement, and for an implant-retained prosthetic-obturator to fit the planned outcome situation for immediate loading.Materials and methodsIn this study, 3D virtual surgical planning and resection of the maxilla, followed by guided placement of 10 zygomatic implants, using custom cutting and drill/placement-guides, was performed on 5 fresh frozen human cadavers. A preoperatively digitally designed and printed obturator prosthesis was placed and connected to the zygomatic implants. The accuracy of the implant positioning was obtained using 3D deviation analysis by merging the pre- and post-operative CT scan datasets.ResultsThe preoperatively designed and manufactured obturator prostheses matched accurately the per-operative implant positions. All five obturators could be placed and fixated for immediate loading. The mean prosthetic point deviation on the cadavers was 1.03 ± 0.85 mm; the mean entry point deviation was 1.20 ± 0.62 mm; and the 3D angle deviation was 2.97 ± 1.44°.ConclusionsIt is possible to 3D plan and accurately execute the ablative surgery, placement of zygomatic implants, and immediate placement of an implant-retained obturator prosthesis with 3D virtual surgical planning.The next step is to apply the workflow in the operating room in patients planned for maxillectomy.

Zygomatic Implant: State of the Art

&#x0D; 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.&#x0D;

Immediate Rehabilitation of the Severely Atrophic Maxilla Using Trans-Sinus Nasal Protocol and Extended Length Subcrestal Angulated Implants. Case Series With 1-Year Follow-Up.

Immediate fixed full-arch rehabilitation of the severely atrophic maxilla eliminates use of a tissue-supported prosthesis during the healing phase and maximizes patient comfort and quality of life. The surgical treatment options available for immediate rehabilitation of the severely atrophic maxilla are dependent on the location and availability of the residual alveolar ridge. When bone is only available in the intercanine region, a graftless approach using tilted distal implants may not provide adequate distance between implants for favorable biomechanics. Subsequently, zygomatic implants are the alternative to provide adequate posterior occlusal support. Use of extended length subcrestal angulated implants offers an additional implant option for the clinician to restore the severely atrophic maxilla immediately. The treatment protocol involves anchorage of the implant fixture to the lateral wall of the nasal bone. The distally tilted implant transverses an augmented sinus cavity and extends to the site of the first permanent molar. The novel implant subcrestal angulation and use of a multi-unit abutment promotes passivity of fit of a full-arch fixed immediate prosthesis. Five clinical case reports from private practice are presented that outline the clinical value of the novel implant design in the rehabilitation of the severely atrophic maxilla. In each case, the use of zygomatic implants would be the only alternative to provide an immediate fixed prosthesis due to the absence of residual alveolar bone in the maxilla premolar and molar regions. The use of extended-length subcrestal angulated (ELSA) implants with straight or angulated multiunit abutments have successfully restored the maxillary arch immediately.

A Zygomatic Bone Study Using Virtual Dental Implant Planning Software.

This study evaluated the anatomical factors that influence the virtual planning of zygomatic implants by using cone-beam computerized tomography (CBCT) scans. CBCT scans of 268 edentulous patients were transferred to specialized implant planning software for the following measurements: maxillo-sinus concavity size (small, medium, and large), zygoma width, implant insertion angle, implant length, and implant apical anchorage. Concavity sizes found were as follows: 34.95% small, 52.30% medium, and 7.35% large. The mean insertion angle was 43.2 degrees, and the average implant apical anchorage was 9.1 mm. The most frequent implant length was 40 mm. Significant differences were found when the different types of concavities in relation to the installation angle, the distance of the apical portion of the implant in contact with the zygomatic bone, and the lateral-lateral thickness of the zygomatic bone were compared (P < .001). Medium-sized maxillary sinus concavity presented greater apical anchorage of the implant (9.7 mm) and was the most frequent type (52.30%). The zygomatic bone is a viable site for zygomatic fixtures, and the use of specialized implant planning software is an important tool to achieve predictable outcomes for zygomatic implants and allows good visualization of the relation between implants and anatomical structures.

Bone reconstruction surgery of complex craniomaxillofacial deformities using additive manufacturing customized implants - a case report

Purpose This study aims to assess the design, manufacturing and surgical implantation of three-dimensional (3D) customized implants, including surgical preoperative planning, surgery and postoperative results, for cranioplasty along with zygomatic and orbital floor implants using additive manufacturing (AM) technics for a 23-year-old female who suffered from severe craniomaxillofacial trauma. Design/methodology/approach The skull biomodel was produced in polyamide while implants were made of Ti-6Al-4V alloy by AM. Findings The method enabled perfectly fitting implants and anatomical conformance with the craniomaxillofacial defect, providing complete healing for the patient. Surgical planning using a customized 3D polyamide biomodel was effective. This proved to be a powerful tool for medical planning and manufacturing of customized implants, as complete healing and good craniofacial aesthetic results were observed. Originality/value Satisfactory surgical procedures, regarding surgery time reduction and good craniofacial aesthetic results, were achieved. Furthermore, the 3D titanium customized implants represented a favorable alternative for the repair of craniomaxillofacial defects.

Micromotion analysis of immediately loaded implants with Titanium and Cobalt-Chrome superstructures. 3D finite element analysis.

ObjectiveThe aim of this study was to evaluate the amount of micromotion of dental implants under immediate loading supported by Titanium (Ti) and Cobalt‐Chrome (Co‐Cr) superstructures.Material and methodsA model of tridimensional half‐edentulous maxilla with three dental implants was made using the Finite Element Analysis (FEA). Two standard and one zygomatic implants were connected to a superstructure with an elliptic section of 6x 3 mm (mm). Two study models were established. Model A: Titanium (Ti) alloy superstructure; Model B: Cobalt‐Chrome (Co‐Cr) alloy superstructure. To simulate an immediate‐loading situation, a friction coefficient of 0.71 was applied between the implant and the bone surface. An axial load of 252.04 [N] was applied on standard and zygomatic implants.ResultsThe Micromotion of dental implants was similar in both superstructure situations. The amount of micromotion was slightly higher in B1 and B3 models (Co‐Cr alloy‐superstructure) compared with A1 and A3 models (Titanium alloy superstructure). The micromotion values in two groups were greater than 150 μm in the incisive region (standard implant) and molar region (zygomatic). In general, the micromotion was higher on the implant that received the load with respect to the other implants. The greater difference was observed when the load was applied on the standard implant A1 (Model A1 = 189.12 μm) compared with standard implant B1(Model B1 = 263.25 μm).ConclusionsWithin the limits of present study, all implants on different load application points showed micromotion; in general, the amount of micromotion was slightly higher in the implants connected with Co‐Cr alloy superstructure.

Survival Rate of Zygomatic Implants for Fixed Oral Maxillary Rehabilitations: A Systematic Review and Meta-Analysis Comparing Outcomes between Zygomatic and Regular Implants.

Background: Zygomatic implants have been proposed alone or in combination with premaxillary conventional implants for severe resorbed maxillary atrophy rehabilitation. The aim of the present investigation was to evaluate through a qualitative systematic review and meta-analysis the survival rate of zygomatic implants in conjunction with regular fixtures for maxillary rehabilitation. Methods: The article screening was conducted on the PubMed/Medline and EMBASE electronic databases according to the “Preferred Reporting Items for Systematic Reviews and Meta-Analyses” (PRISMA) guidelines. The scientific papers were included for qualitative analysis and risk-of-bias evaluation. Only the papers that included rehabilitation with zygomatic implants in combination with regular implants were considered for the meta-analysis comparative evaluation of the implant survival rate. Results: The paper search screened a total of 137 papers. After the initial screening, a total of 32 articles were considered for the qualitative analysis. There was a similar implant survival rate between zygomatic and premaxilla regular implants (p = 0.02; Z: 2.26). Conclusions: Zygomatic and conventional implants showed a high long-term survival rate for fixed maxillary rehabilitations, but few included studies reported the marginal bone loss after loading. Further studies are necessary to evaluate the pattern of marginal bone loss between zygomatic and conventional implants after long-term functional loading.

Combined bone- and mucosa-supported 3D-printed guide for sinus slot preparation and prosthetically driven zygomatic implant placement

The use of zygomatic implants to rehabilitate the severely atrophic maxilla has been well documented since first being introduced by Brånemark. Placement of zygomatic implants is technically complex, with catastrophic complications and numerous prosthetic challenges resulting from imprecise placement. The purpose of this report was to demonstrate a technique that allows transfer of the preoperatively planned sinus slot position to the surgical field by using cone beam computed tomography (CBCT) and an implant planning software program to fabricate a combined bone- and mucosa-supported 3D-printed surgical guide. This facilitates optimal zygomatic implant positioning and promotes favorable biomechanics with a predictable prosthetic outcome.

Evaluation of Quality of Life and Satisfaction in Patients with Fixed Prostheses on Zygomatic Implants Compared with the All-on-Four Concept: A Prospective Randomized Clinical Study.

Purpose: No published research has compared patients’ quality of life and satisfaction with fixed prostheses supported by zygomatic implants with those supported by all-on-four prostheses. The aim of this study was to evaluate patients’ quality of life and satisfaction with fixed prostheses on zygomatic implants compared with the all-on-four concept. Materials and Methods: A total of 80 patients with atrophic edentulous maxillae were randomized into two groups: Group 1 (rehabilitated with fixed prostheses supported by 2–4 zygomatic and 2–4 conventional implants in the anterior region) and Group 2 (fixed prostheses on four implants in the anterior region following an all-on-four concept). One year after placement of the definitive prostheses, patients completed OHIP-14 and satisfaction questionnaires. Results: In all seven domains of the OHIP-14 and in the overall scores, a worse quality of life was found in Group 2 patients, with statistically significant differences between the two groups (p ≤ 0.05). Patients with zygomatic implants were more satisfied with their prostheses, with a statistically significant difference (p < 0.001). Conclusions: According to the results of this study, rehabilitation of patients with edentulous atrophic maxillae with prostheses supported by zygomatic implants combined with anterior implants provided better patient quality of life and satisfaction than prostheses supported by four implants.

Complications related to zygomatic implants placement: A retrospective evaluation with 5 years follow-up

This retrospective study assessed zygoma implants in patients treated for upper maxilla extreme atrophy, trauma, cleft palate, or failed reconstruction.The implants were placed using Quad (4 zygoma implants) or mixed (zygoma and conventional implants in premaxilla) surgical technique, with intra-sinus or extra-sinus approach, followed by immediate or deferred loading. Clinical and radiographic evaluations were carried out at 5-year follow-up from loading. Implant survival, symptoms and signs of sinusitis, radiological alterations in terms of mucosal thickening or obliteration of the maxillary sinuses, oroantral communications, and peri-implant soft tissues were examined.A total of 42 patients, with 116 zygoma implants, were included in the study. The cumulative survival rate was 97.41%. One zygomatic bone fracture was assessed. Eight patients reported sinusitis, and two showed oro-antral communications. A comparison between mean pre- and post-operative Lund–Mackay scores showed a statistically significant increase of sino-nasal disease in the post-operative scores (p = 0.0019). Mucositis and gingival recession was observed in 21 and 8 implants respectively. Average recession was 2.52 ± 2.35 mm.According to our results, placement of zygoma implants has proved to be a predictable procedure, with a lower rate of severe complications compared to other treatment options in extreme upper jaw atrophy.

Zygomatic implant-supported prosthodontic rehabilitation of edentulous patients with a history of cleft palate: A clinical report

Zygomatic implants are an established treatment option in the management of the atrophic maxilla and in oncology rehabilitation, but evidence for their use in patients with a history of cleft palate is sparse. Zygomatic implants were used to retain a maxillary prosthesis in 7 edentulous patients with an unrepaired or repaired cleft lip and palate. Patient records were reviewed retrospectively to assess the survival rates. The mean follow-up time was 5 years with an implant survival of 100%. Most complications were associated with the prosthetic superstructures. This clinical report demonstrates that zygomatic implants can be successfully used to provide a maxillary prosthesis in patients with a history of cleft palate.

Three-dimensional measurement of radiographic bone–implant contact lengths of zygomatic implants in zygomatic bone: a retrospective study of 66 implants in 28 patients

Zygomatic implant treatment is widely applied for severe maxillary atrophy to help rehabilitate the maxillary dentition. This retrospective study was performed to evaluate the actual radiographic bone–implant contact (rBIC) lengths of zygomatic implants. The records of 28 patients who underwent zygomatic implant surgery and subsequent follow-up examinations between August 2013 and September 2018 in the Department of Oral and Maxillofacial Surgery, Taipei Tzu Chi Hospital were reviewed. The surgeries were performed by a single surgeon using the same treatment protocol. All patients had a computed tomography scan at 1year after the surgery. Using three-dimensional imaging software, an investigator measured the rBIC lengths of 66 implants and documented their clinical status. The implant survival rate was 100%. The mean rBIC length was significantly longer in male patients than in female patients (20.80±5.88mm versus 17.79±6.34mm; P=0.028). The mean rBIC length of double zygomatic implants was significantly longer when compared to that of single implants (21.11±6.23mm versus 17.75±5.85mm; P=0.027). This article is novel in reporting the exact rBIC lengths of zygomatic implants in a clinical setting. The results showed that zygomatic implants are a viable treatment modality for full-mouth rehabilitation.

Quad Zygomatic Implants: A Systematic Review and Meta-analysis on Survival and Complications.

To assess the postoperative complications and outcome (implant survival) of quad zygomatic implants inserted in patients with edentulism and severely atrophic maxillae. Two independent reviewers conducted an electronic search of the literature (PubMed, Scopus, EBSCO, Web of Science) from January 2000 to February 2019. The inclusion criteria were articles published in English reporting data of at least five patients with severely atrophic edentulous maxillae undergoing placement of four zygomatic implants without additional insertion of standard implants, with a minimum of 6 months of follow-up. Data extracted included number of patients, characteristics of the maxillary defect, number of zygomatic implants, implant details, surgical procedure, prosthetic rehabilitation, postoperative complications, survival rate, and length of follow-up after definitive prosthesis delivery. Eleven studies with 166 patients were included. The heterogeneity among studies was not significant. The pooled incidence rates of complications were as follows: sinusitis 12% (95% confidence interval [CI]: 4% to 23%), malposition and surgical guiding failure 11% (95% CI: 3% to 21%), local infection/injury 10% (95% CI: 3% to 18%), and prosthetic complications 5% (95% CI: 0% to 13%). The implant survival rate ranged between 95.8% and 100%, and the pooled implant survival rate in the meta-analysis was 98% (95% CI: 97% to 99%). Quad zygomatic implants inserted in patients with severely atrophic edentulous maxillae have a high implant survival rate, but the incidence of complications should not be underestimated.