Immediate full-arch rehabilitation of the severely atrophic maxilla supported by zygomatic implants: a prospective clinical study with minimum follow-up of 6 years

Zygomatic Implants in a Patient With History of Mucormycosis: A Case Report

Exposure to mucor mold can lead to mucormycosis, a rare fungal infection with severe consequences, especially in immunocompromised individuals. The year 2020 highlighted the need for orofacial rehabilitation, presenting challenges in cases of maxillary absence. This case report details zygomatic implants, which offer a promising solution by providing stable support even in the absence of significant bone mass due to surgical excision post-COVID-19 mucormycosis. Zygomatic implants outperform traditional grafting techniques. The atrophic or resected jaws can be effectively restored with a single-piece zygomatic implant, which has the lowest rate of postoperative problems, including bone loss, mucositis, peri-implantitis, and screw loosening or fractures. In this case report, four zygomatic implants were placed in the zygomatic bone, and immediate loading was performed. Restoration of patient aesthetics, phonetics, and functional masticatory efficiency were restored.

Comparative Evaluation of Sinus Complication and Survival Rates of Quad Zygoma versus Bizygoma in Combination with two Regular Implants in Atrophic Maxilla: A Systematic Review and Meta-Analysis

Aim

To systematically review existing scientific literature to determine, compare and evaluate the sinus complication and survival rates of quad zygoma against two zygomatic implants with combination of two regular implants in atrophic maxilla in adults.

Methods

Review was performed in accordance with preferred reporting items for systematic reviews and meta-analysis guidelines and registered in PROSPERO-CRD42023392721 Electronic databases like PubMed, Google scholar and EBSCO host were searched from 2000 to December 2022 for studies reporting treatment of Atrophic maxilla with either quad zygoma or two zygomatic implants in combination with two regular implants. Quality assessment was evaluated using Cochrane risk of bias-2 tool for randomized controlled trials (RCT). The risk of bias summary graph and risk of bias summary applicability concern was plotted using RevMan software version 5.3. The odds ratio (OR) and standardized mean difference (SMD) were used as summary statistic measure with random effect model and p value < 0.05 as statistically significant.

Results

Eleven studies fulfilled the eligibility criteria and were included in qualitative synthesis, of which only nine studies were suitable for meta-analysis. The pooled estimate through the odds ratio 0.59 signifies that the quad zygomatic implants on an average has 0.59 (0.18-1.93) times or odds of developing sinus complications while the SMD signifies that better survival rate (SR) on an average is 0.35 (- 0.61 to 1.30) times more by two zygomatic implants with combination of two regular implants as compared to quad zygomatic implants (p > 0.05). Publication bias through the funnel plot showed asymmetric distribution with systematic heterogeneity.

Conclusion

Two zygomatic implants in combination with two regular implants provides better survival rate and less sinus complications compared to quad zygoma in atrophic maxilla. Despite the high SR observed, there is a need to conduct more randomized controlled clinical trials to examine their efficacy in comparison with other techniques.

Fiber-Reinforced Composites for Full-Arch Implant-Supported Rehabilitations: An In Vitro Study

Background: Fiber-reinforced composites (FRCs) have been proposed as an alternative to traditional metal alloys for the realization of frameworks in full-arch implant-supported prostheses. The aim of the present in vitro study was to evaluate the deflection under load of seven prostheses endowed with frameworks made of different materials, including different types of fiber-reinforced composites (FRCs). Methods: A master cast with four implant analogues in correspondence with the two lateral incisors and the two first molars was used to create full-arch fixed prostheses with the same shape and different materials. Prostheses were made of the following different materials (framework+veneering material): gold alloy+resin (Au+R), titanium+resin (Ti+R), FRC with multidirectional carbon fibers+resin (ICFRC+AR), FRC with unidirectional carbon fibers+composite (UCFRC+C), FRC with glass fibers+resin (GFRC+AR), FRC with glass fibers+composite (GFRC+C), and resin (R, fully acrylic prosthesis). Flexural tests were conducted using a Zwick/Roell Z 0.5 machine, and the deflection of the lower surface of the prosthesis was measured in order to obtain load/deflection graphs. Results: Greater rigidity and less deflection were recorded for UCFRC+C and GFRC+C, followed by Ti+R and Au+R. The greatest deformations were observed for resin alone, ICFRC+R, and GFRC+R. The results were slightly different in the incisal region, probably due to the greater amount of veneering material in this area. Conclusions: When used to realize full-arch frameworks, Au and Ti allow for predictable mechanical behavior with gradual deformations with increasing load. UCFRC also demonstrated good outcomes and less deflection than ICFRCs when loaded. The GFRC full-arch framework may be a valid alternative, although it showed greater deflections. Further studies are needed in order to evaluate how different prosthesis designs and material thicknesses might affect the outcomes.

Quad Zygoma: A Graftless Solution in Post-mucormycosis Maxillectomy

Mucormycosis, a fungal infection that commonly affects individuals with diabetes and compromised immune systems, often requires surgical excision and debridement. However, this can result in significant defects, posing a challenge for clinicians in terms of reconstruction and rehabilitation. Prostheses, local and regional pedicled flaps with or without bone grafts, and titanium mesh application are available options for maxillary reconstruction. Soft-tissue flaps are not sufficient to provide osseointegrated implants with both bone repair and structural support, which emphasises the quad zygoma's beneficial role in treating maxillary abnormalities. Patients benefit from quad zygoma, which uses zygomatic implants and eliminates the need for subsequent procedures, which shortens the course of treatment and lowers costs. Because zygomatic implants are securely fixed into the zygoma, temporary prostheses can be loaded right away. Then, four to six months later, a fixed prosthesis may be introduced. Clinical results with zygomatic implants often surpass those of bone grafting, representing a potential novel gold-standard approach for the compromised maxilla. This case report details the rehabilitation of post-mucormycosis patients with maxillary defects using quad zygomatic implants. The absence of complications during follow-up, conducted at 15, 30, 45, and 90 days, and subsequently monthly for two years, highlights the success of this approach. Evaluation parameters included soft tissue recovery, infection, wound separation, stability of prosthesis, eating effectiveness, and aesthetic outcomes. The positive outcomes observed at follow-up appointment emphasize the viability and effectiveness of quad zygomatic implants in addressing maxillary defects post-mucormycosis.

Rehabilitation of the severely resorbed maxilla by using quad zygomatic implant-supported prostheses: a systematic review and meta-analysis

STATEMENT OF PROBLEM

Quad zygomatic implants have been used as a treatment option for patients with a severely resorbed maxilla. However, data on the average rate of success of the prosthesis, survival of the zygomatic implants, and associated complications are sparse.

PURPOSE

The purpose of this systematic review and meta-analysis was to assess prosthetic and zygomatic implant success of treating severe maxillary resorption with prostheses supported by 4 zygomatic implants, with an additional review on potential complications.

MATERIAL AND METHODS

A comprehensive search of studies published in English between January 2001 and December 2020 was performed in the PubMed, OVID, EBSCO, and EMBASE databases according to the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. The study was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID: CRD42021219468). The population, intervention, comparison, and outcome (PICO) question was "What is the effectiveness of oral rehabilitations using only 4 zygomatic implants placed in severely resorbed maxillae?" The search results were subjected to a systematic review for articles reporting prosthetic success and zygomatic implant survival. Prosthetic success was analyzed by using a fixed-effects inverse-variance model. The random-effects model was adopted for meta-analysis as moderate heterogeneity was identified among studies that reported implant survival in quad zygoma treatments. The quality of publications was appraised by using the Critical Appraisal Skills Program (CASP) checklists.

RESULTS

Of the 82 titles, 7 studies that met the inclusion criteria without an overlap of patient cohorts were quantitatively analyzed for the average rate of prosthetic success and implant survival. All prostheses in the aggregated studies were immediately loaded with acrylic resin interim prostheses replaced by a definitive prosthesis, which consisted of overdentures retained by bar splinting (n=2), metal bar-reinforced prostheses (n=2), fixed screw-retained acrylic resin prostheses (n=34), and screw-retained titanium prostheses with ceramic or acrylic resin teeth (n=75). Technical complications of zygomatic implants included mobility associated with a machined surface and fracture of the abutment screw. The most common prosthetic complications reported were fracture of the definitive prosthesis and loss of the interim prosthesis subsequent to the failure of at least 1 zygomatic implant. The results showed that prostheses supported by quad zygoma implants displayed an overall success of 100% (CI=95%, I2=0.00%, P=.850), whereas zygomatic implants showed a survival rate of 98% (CI=95%, I2=60.48%, P=.040) with minimal implant failures and few complications.

CONCLUSIONS

Although the data analysis showed favorable results for rehabilitating severely resorbed maxillae by using quad zygoma with high prosthetic success and high implant survival rate, further long-term clinical studies are required to strengthen the evidence. However, potential implant and prosthetic complications should be considered while planning this treatment approach.

Clinical outcomes of implant-supported prosthetic rehabilitation of severely atrophic maxilla: A systematic review

Aim

The purpose of this systematic review is to evaluate the clinical outcomes for the various methods of rehabilitation of a severely atrophic maxilla with the help of implant-supported fixed prosthesis.

Materials and Methods

The relevant publications published between 2013 and 2022 and written only in English were identified using an electronic search. The primary research question for this study was developed based on the PICO framework, which stands for population, intervention, control, and outcomes which was "What are the clinical outcomes of implant-supported prosthetic rehabilitation in patients with severely atrophic maxilla?" The relevancy of the articles was confirmed by examining their titles, abstracts, and complete texts to determine whether they satisfied the requirements for inclusion. Utilizing specialized study design-related bias assessment forms, the risk of bias was evaluated.

Results

The database search resulted in 1568 results; however, 1529 of them were eliminated because of insufficient, duplicate, or missing data. Additionally, manual searching yielded 11 articles. After 50 full-text papers were assessed for eligibility, 17 articles were eliminated. Thus, 33 studies in total are included in the current systematic review. Risk of bias analysis and GRADE evidence analysis were performed. Data were found to be heterogeneous and thus meta-analysis could not be done and narrative synthesis is presented.

Conclusion

The patient's condition and the clinician's expertise play a role in taking the decision on choice of technique for the fixed implant-supported rehabilitation of the severely atrophic maxilla. A high success and survival rate is produced by the majority of fixed implant-assisted prostheses despite the biologic and prosthetic problems. A single approach cannot be recommended as the gold standard. The choice is dependent on the patient's biological factors as well as the clinician's expertise. The included studies were assessed using GRADE criteria. The quality of evidence is low-medium. Therefore, to better comprehend the clinical effectiveness of the treatment alternatives, more well-designed randomized controlled trials with longer follow-up period are required.

Five Steps for the Maintenance and Interception of Complications in Zygomatic Implants

Zygomatic implants are used for the rehabilitation of the upper jaw of patients with severe and moderate bone atrophy. Possible post-surgical complications include soft tissue dehiscence, sinusitis, and prosthodontic fractures, and maintaining an accurate control is crucial. Additionally, zygomatic implants have a unique peri-implant anatomy, making traditional periodontal parameters unsuitable. The present paper aims to provide guidelines for the maintenance and interception of complications in patients rehabilitated with these kinds of implants. The proposed protocol includes: 1. intra/extraoral and temporo-mandibular joint examination; 2. soft tissue and transmucosal path observation with magnifiers; 3. peri-implant health indices and digital stimulation of tissues; 4. examination of prosthodontic devices; and 5. photographic recording. These steps facilitate the comprehensive evaluation and monitoring of clinical conditions of zygomatic-supported rehabilitations, including dehiscence and occlusal wear during follow-up appointments.

Long-term treatment outcomes with zygomatic implants: a systematic review and meta-analysis

PURPOSE

The purpose of this study was to perform a systematic review with meta-analysis on the long-term survival rates of zygomatic implants (ZI). ZI success, prostheses survival and success, sinus pathology and patient reported outcomes were also investigated.

METHODS

Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines were followed. Embase and OvidMedline databases were searched alongside the grey literature. The systematic review was recorded in PROSPERO (CRD42022358024). Studies reporting titanium/titanium alloy ZI survival data, ZI-supported prosthesis data, ZIs directly compared to any other implant therapy including grafted sites, a minimum follow-up time of 3 years and a minimum number of 10 patients were included. All study designs were considered if they met the inclusion criteria. Studies not involving ZIs, ZIs not made from titanium/titanium alloy, a follow-up time of < 3 years or < 10 patients, animal studies and in vitro studies were excluded. Long-term follow-up has not been defined in the literature. A minimum of 3 years follow-up was considered acceptable to capture survival after initial healing, alongside in-function prosthesis data via delayed or immediate load protocols. ZI success, was predominantly defined as ZI survival without biological or neurological complications. Meta-analyses were performed for ZI survival, ZI failure incidence, ZI success, loading protocol, prosthesis survival, and prevalence of sinusitis using random effects models. Descriptive analysis was used for ZI success, prosthesis success and patient reported outcome measures.

RESULTS

Five hundred and seventy-four titles were identified, of which 18 met the inclusion criteria. Eligible studies included 1349 ZIs in 623 patients. Mean follow-up period was 75.4 months (range 36-141.6). The mean survival of ZIs was 96.2% [95% CI: 93.8; 97.7] at 6 years. Mean survival for delayed loading was 95% [95% CI: 91.7; 97.1] and 98.1% [95% CI: 96.2; 99.0] for immediate loading (p = 0.03). Annual incidence rate of ZI failure was 0.7% [95% CI 0.4; 1.0]. Mean ZI success was 95.7% [95% CI 87.8; 98.6]. Mean prosthesis survival was 94% [95% CI 88.6; 96.9]. Sinusitis prevalence was 14.2% [95% CI 8.8; 22.0] at 5 years. Patients' reported increased satisfaction with ZIs.

CONCLUSIONS

ZIs have long-term survival comparable to conventional implants. Immediate loading showed a statistically significant increase in survival over delayed loading. Prosthesis survival was similar to that of prostheses supported by conventional implants, with similar complications. Sinusitis was the most frequently encountered biological complication. Patients reported improved outcome measures with ZI use.

Indications for zygomatic implants: a systematic review

PURPOSE

The purpose of this systematic review was to assess the evidence regarding the indications for placement of zygomatic implants to rehabilitate edentulous maxillae.

MATERIAL AND METHODS

A focused question using the PIO format was developed, questioning "in patients in need of an implant-supported rehabilitation of the edentulous maxillae, what are the indications for the use of zygomatic implants''. The primary information analyzed and collected was a clear description of the indication for the use of zygomatic implants.

RESULTS

A total of 1266 records were identified through database searching. The full-text review was conducted for 117 papers, and 10 were selected to be included in this review. Zygomatic implant indications were extreme bone atrophy or deficiency secondary to different factors. The quad zygoma concept (two zygomatic implants bilaterally placed and splinted) was applied to 107 patients, the classic zygoma concept (one zygomatic implant bilaterally placed and splinted to standard anterior implants) was used in 88 patients, and the unilateral concept (one zygomatic implant on one side, splinted with one or more conventional implants) was employed in 14 patients.

CONCLUSIONS

The main indication for the use of zygomatic implants was considered extreme maxillary bone atrophy, resulting from many factors. The clear definition of what was considered "extreme bone atrophy" is not uniquely defined in each paper. Further studies are needed to develop clear indications for zygomatic implants.

Survival and complications of zygomatic implants compared to conventional implants reported in longitudinal studies with a follow-up period of at least 5 years: A systematic review and meta-analysis

BACKGROUND

Zygomatic implants (ZI) have been frequently indicated to rehabilitate patients with extensive atrophies in alternatives to major bone reconstructions. It can be installed inside the maxillary sinus, called instrasinus zygomatic implant (IZI) or outside the maxillary sinus (EZI), depending on the surgery technique.

OBJECTIVE

To evaluate the survival and complication rates of ZI in longitudinal studies when compared with conventional implants (CI).

METHODS

An electronic search was performed in five databases and in Gray literature for articles published until April, 2022. The eligibility criteria comprised observational cohort studies (prospective or retrospective) and randomized clinical trials (RCTs) with at least 5 years of follow-up, reporting survival rate of ZI versus CI. A meta-analysis was conduct with 18 studies.

RESULTS

A total of 5434 implants (2972 ZI and 2462 CI) were analyzed in 1709 patients. The mean survival rate was 96.5% ± 5.02 and 95.8% ± 6.36 for ZI and CI, respectively (mean follow-up time of 78 months). There were observed no statistically significant between ZI and CI in prospective studies (risk ratio [RR] of 1.21; 95% confidence intervals [CIs]: 0.28 to 5.28; chi-squared [Chi² ] = 11.37; I²  = 56%; degrees of freedom [df] = 5; z-score = 0.25; P = 0.80), retrospective studies IZI (RR of 1.29; 95% CIs: 0.52 to 3.23; Chi²  = 4.07; I²  = 2%; df = 4; z-score = 0.55; P = 0.58) and retrospective studies EZI (RR of 0.72; 95% CIs: 0.31 to 1.66; Chi²  = 1.99; I²  = 0%; df = 3; z-score = 0.78; P = 0.44). The biological complications most related to ZI was sinusitis, followed by infection and oroantral communication.

CONCLUSION

ZI have a high long-term survival rate (96.5% with a mean of 91.5 months of follow-up), showing no significant difference when compared with CI. The most prevalent biological complication is sinusitis, being most commonly to the IZI technique. This systematic review (SR) was registered in INPLASY under number INPLASY202280025.

A single-arm clinical trial investigating the feasibility of the zygomatic implant quad approach for Cawood and Howell Class 4 edentulous maxilla: An option for immediate loading

INTRODUCTION

The traditional way to treat maxillary edentulous Cawood and Howell Class 4 (CH4) patients who exhibit the knife-edge ridge form of edentulous jaws that are adequate in height and inadequate in width is extensive autologous bone grafting for conventional implant placement.

PURPOSE

To evaluate the feasibility of the zygomatic implant (ZI) quad approach in edentulous CH4 patients who presented a knife-edge ridge form in the anterior maxilla for immediate loading.

MATERIAL AND METHODS

Eligible patients with maxillary CH4 edentulism treated with the ZI quad approach were enrolled. Bone reduction and implant placement were performed under the guidance of a navigation system according to preoperative planning. The outcome variable was the implant survival rate, and additional variables were the ratio of immediate loading, complications and the relationship of the zygomatic implant path to the sinus wall. Statistical analysis was performed with the SAS statistical package.

RESULTS

Fifteen patients (3 men, 12 women; age range, 19-71 years; average age 47.2 years) eligible for the study received the ZI quad approach from January 2017 through January 2020. All ZIs achieved osseointegration, with no implant loss after early healing and a mean follow-up of 17.2 ± 6.2 months. Thirteen of 15 patients (86.7%) received immediate loading. No critical anatomic structure injuries occurred during surgery. Most mesially placed implants (23/30, 76.6%) presented ZAGA 2 and 3, and most distally placed implants were distributed in ZAGA 0 (20/30, 66.7%).

DISCUSSION

In terms of realizing immediate loading in CH4 patients with a knife-edge ridge form in the anterior maxilla, quad approaches have advantages over other grafting methods. At the same time, it seems the survival rate of zygomatic implants is comparable with that of other indications. With the limitations of this study, the quad approach might be a feasible option to realize edentulous maxillary reconstruction and to make immediate loading possible.

Accuracy of digital planning in zygomatic implants

Background

Zygomatic 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.

Results

Fourteen 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).

Conclusions

Zygomatic 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.

Survival Rate and Prosthetic and Sinus Complications of Zygomatic Dental Implants for the Rehabilitation of the Atrophic Edentulous Maxilla: A Systematic Review and Meta-Analysis

Simple Summary

Zygomatic dental implants have been proposed as an alternative to atrophic total edentulous maxillae rehabilitation with the necessity of bone grafting procedures. However, surgical, prosthetic, and maxillary sinus complications have been associated with this surgical procedure. Therefore, it is necessary to produce a systematic review and meta-analysis that provides evidence associated with the prognosis when using zygomatic dental implants as an alternative to atrophic total edentulous maxillae rehabilitation.

Abstract

The aim of this systematic review and meta-analysis was to analyze and compare the survival rate and prosthetic and sinus complications of zygomatic dental implants for the rehabilitation of the atrophic edentulous maxilla. Materials and methods: We conducted a systematic literature review and meta-analysis, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations, of clinical studies that evaluated the survival rate and prosthetic and sinus complications of zygomatic dental implants for the rehabilitation of the atrophic edentulous maxilla. Four databases were consulted during the literature search: Pubmed–Medline, Scopus, Embase, and Web of Science. After eliminating duplicate articles and applying the inclusion criteria, 46 articles were selected for the qualitative analysis and 32 for the quantitative analysis. Results: Four randomized controlled trials, 19 prospective clinical studies, 20 retrospective studies, and 3 case series were included in the meta-analysis. Conventional dental implants failure (n = 3549) were seen in 2.89% (IC-95% 1.83–3.96%), while zygomatic dental implants failure (n = 1895) were seen in 0.69% (IC-95% 0.21–1.16%). The measure of the effect size used was the Odds Ratio, which was estimated at 2.05 with a confidence interval of 95% between 1.22 and 3.44 (z test = 2.73; p-value = 0.006). The failure risk of conventional dental implants is 2.1 times higher than that of zygomatic dental implants. Slight heterogeneity was determined in the meta-analysis between 23 combined studies (Q test = 32.4; p-value = 0.070; I² = 32.1%). Prosthetic complications were recorded in 4.9% (IC-95% 2.7–7.3%) and mild heterogeneity was observed in a meta-analysis of 28 combined studies (Q test = 88.2; p-value = 0.001; I² = 69.4%). Sinus complications were seen in 4.7% (IC-95% 2.8–6.5%) and mild heterogeneity was observed in a meta-analysis of 32 combined studies (Q test = 75.3; p-value = 0.001; I² = 58.8%). Conclusions: The high survival rate and low prosthetic and sinus complications related to zygomatic dental implants suggest the use of zygomatic dental implants for the rehabilitation of the atrophic edentulous maxilla.

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

BACKGROUND

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.

PURPOSE

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.

MATERIALS AND METHODS

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.

RESULTS

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%).

CONCLUSIONS

Immediate rehabilitation of the severely atrophic maxilla with zygomatic implants alone or in combination with standard implants could be considered a viable treatment modality.

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.

Full arch rehabilitation in patients with atrophic upper jaws with zygomatic implants: a systematic review

Background

The main objective of this systematic review was to present the outcomes of the treatment with zygomatic implants (ZIs) in the rehabilitations of atrophic upper jaw.

Findings

An electronic database search in PubMed, along with a manual search, taking into account language and study period, was performed by two observers; any type of clinical trial and series that included the use of ZIs was used. In the search strategy, the following search terms were used: zygom* AND dental (Implant OR implants) AND edentulous NOT (biomechanic* OR finite element) NOT cadaver. The search was limited to English language, full text, and humans. Literature reviews and clinical case reports were not considered. Forty-two articles published between March 2003 and April 2019 were included in this analysis. The cases of 1247 patients were recovered; these patients received 2919 ZIs. Fifty-two ZIs were removed during the follow-up time. The survival rate of these implants was 98.22%, with a minimum follow-up of 1 month and a maximum of 228 months. Different surgical techniques were used to place ZIs; however, the intrasinusal technique was the most used (23 studies). Post-surgical sinusitis was the most common complication reported in the studies (39 cases).

Conclusions

Based on this review, ZIs were commonly used for rehabilitation of patients with atrophic upper jaw. The survival rates presented were high, and the surgical technique is dependent on the professional experience and the local anatomy. However, it needed additional clinical evidence on bone resorption, esthetic outcomes, and physiological characteristics.

Extrasinus Zygomatic Implants for the Immediate Rehabilitation of the Atrophic Maxilla: 1-Year Postloading Results From a Multicenter Prospective Cohort Study

PURPOSE

The use of zygomatic implants is an alternative to major grafting procedures for the treatment of the atrophic posterior maxilla. However, only few studies reported solid and correct data about the use of extrasinus zygomatic implants. Starting from these considerations, this study aims to investigate the 1-year survival and success rates of extrasinus zygomatic implants immediately loaded in patients with severe atrophy of the posterior maxilla.

METHODS

Twenty-three consecutive patients fully edentoulus or with failing dentition in the upper arch and with a severe atrophy of the posterior maxilla were enrolled. All patients underwent prosthodontic rehabilitation with the application of implants in both anterior maxilla areas and zygomatic bone. All the zygomatic implants were inserted with an extrasinus path. Primary outcomes were prosthesis and implant failures. Secondary outcomes were complications, bleeding scores, probing pocket depths, and peri-implant marginal bone-level changes. A total of 98 implants were inserted.

RESULTS

During the 1-year follow-up, no implant failure was reported as well as no pain and/or no sinusitis were detected. No other significant events were reported, except for minor soft tissue and technical problems. A maxillary sinus membrane rupture occurred during the surgical phase in 4 (17.4%) patients, but healing was not compromised. Peri-implant mucositis was observed in 2 (8.7%) patients. Twelve months after surgery, average bone loss around conventional implants was 1.11 ± 0.23 mm. In addition, no peri-implant radiolucency was observed around zygomatic implants. Within the limits of this study, preliminary short-term data (1-year after loading) suggested that extrasinus zygomatic implants represent a predictable treatment option for the atrophic maxilla. Further follow-up data (≥5 years) are needed to confirm these results.

CONCLUSIONS

The present study supports the conclusion that extrasinus zygomatic implants for the immediate rehabilitation of the atrophic maxilla have high success rate with minimal or no complications.

Extramaxillary Zygomatic Implants: An Alternative Approach for the Reconstruction of the Atrophic Maxilla

Background

Limited bone quality in the posterior maxilla results in low success rates for dental implants. Various bone augmentation methods have been described, yet most require two-step surgical procedures with relatively high rates of resorption and failure. An alternative for these patients is zygomatic implants. Zygomatic implants utilize the basal craniofacial bone.

Materials and Methods

A retrospective study was conducted on 25 patients exhibiting ridges classified as V-VI according to the Cawood and Howell classification. Seventy-six extramaxillary zygomatic implants were placed. Immediate rehabilitation was performed with a mean follow-up of 18.6 months.

Results

Three implants failed, and two were replaced successfully. No significant bone loss was observed in the rest of the implants. Soft tissue around the implant heads healed properly. All implants were prosthetically rehabilitated successfully.

Conclusions

Zygomatic implants allow for immediate loading of an atrophic maxilla. The emergence of the implant is prosthetically correct compared to the intrasinus approach, leading to better dental hygiene and decreased mechanical resistance. 96.1% of the implants survived, with good anchorage and proper soft tissue healing and rehabilitation. We suggest using extramaxillary zygomatic fixture as the first line of treatment in severe atrophic maxilla.

Quality assessment of systematic reviews regarding the effectiveness of zygomatic implants: an overview of systematic reviews

Background

Oral rehabilitation of atrophic maxillae features high complexity, for which there are several therapeutic modalities reported on scientific literature. Zygomatic implant placement is a viable option that features low morbidity and allows immediate prosthetic loading. The purpose of the present study was to determine the methodological quality of systematic reviews that assessed the effectiveness of zygomatic implants placed in atrophic maxillae.

Material and Methods

Searches were conducted on Medline via Pubmed, LILACS, Dare Cochrane, Scopus, and Sigle via Open Grey up to June 2019.

Results

Seven systematic reviews were eligible for Overview and comprised a total of 2313 patients, 4812 zygomatic implants, and a 96,72% success rate. Common surgical complications, in decreasing order, were: maxillary sinusitis, peri-implant mucositis, prosthetic fracture, and infections. Methodological quality was assessed using the AMSTAR 2 tool, which revealed that six systematic reviews showed critically low methodological quality and one review was assessed as of low methodological quality.

Conclusions

Zygomatic implants seem to be an adequate option for atrophic maxilla rehabilitation, however, new studies with a higher methodological rigor are needed to provide more reliable results to professionals and patients undergoing this modality of oral rehabilitation.

Key words:Zygomatic Implants, dental Implants, complications, oral rehabilitation.

Clinical Performance of Zygomatic Implants-Retrospective Multicenter Study

The main objective of this analysis was to evaluate (1) implant survival, (2) biologic complications, and (3) demographics associated with zygomatic implants placed according to the zygomatic anatomy-guided approach (ZAGA). This retrospective multicenter study reviewed data from the charts of 82 consecutive patients who had received 182 zygomatic implants. Patients were fully edentulous (62.2%), partially edentulous (22.0%), or had failing dentition (15.9%). Most patients (87.5%) did not have previous sinusitis and 11.3% had been previously treated for it. Additionally, about half of the patients (53.8%) did not present periodontal pathology, and one-third (36.3%) did, but were subsequently treated. Most implants (93.8%) were loaded immediately, i.e., within 48 h of placement. Implants were followed for 10.5 ± 7.2 months, and all were recorded as surviving and stable at last follow-up. Post-operative complications were infrequent and included sinusitis (10.1%) and peri-implant hyperplasia (0.8%). The low complication rate and 100% implant survival and stability indicate that zygomatic implants offer a viable treatment option when performing graftless restoration of severely resorbed maxilla, including immediate loading protocols.

The Workflow of a New Dynamic Navigation System for the Insertion of Dental Implants in the Rehabilitation of Edentulous Jaws: Report of Two Cases

Background: This case series describes the surgical workflow during maxillary full-arch rehabilitations in two patients through the All-on-4 concept (standard and hybrid) assisted by DTX Studio Implant Software planning and X-Guide Navigation. Results: The X-Guide Navigation enabled the drills and implants to be positioned and oriented precisely, allowing the implants to be positioned favorably under the surgical and prosthetic points of view through the avoidance of damage to the maxillary sinus and nasal cavity. Dynamic navigation-assisted surgery provided advantages, including the possibility to modify the implants’ system, length, or location perioperatively. However, it must be underlined that to achieve proficiency with this technology it is necessary to consider a necessary learning curve. Conclusion: The insertion of dental implants assisted by dynamic navigation for maxillary full-arch rehabilitations was considered a safe and predictable procedure. Nevertheless, it can be improved (such as with a simpler fiducial markers protocol), aiming to simplify the procedure.

A Systematic Review of Survival Rates of Osseointegrated Implants in Fully and Partially Edentulous Patients Following Immediate Loading

Background: The aim of this systematic review was to evaluate the survival rates of immediately loaded implants after at least five years. Besides implant failure, the amount of marginal bone loss around implants and the complication type were assessed. Methods: The electronic search was undertaken on Medline, Scopus, and Cochrane Central Register of Controlled Trials using key terms such as: “immediate loading”, “immediate function”, “immediate restoration”, “immediate temporization”, “dental implants”, “fully edentulous patients”, “partially edentulous patients”. The search terms were combined using the Boolean operators AND, OR. The last electronic search was performed on 15 February 2018. Two authors independently screened the studies, extracted the data, and assessed the risk-of bias. The main outcomes recorded for each study were: implant and prosthesis success and survival, marginal bone level change, incidence and type of complications. Kaplan–Meier analysis was used to estimate cumulative survival rates. Results: Thirty-four prospective studies with at least five-year follow-up, published between 2007 and 2017 were included. A total of 5349 immediately loaded implants in 1738 patients were analyzed. The mean follow-up was 72.4 months (median 60 months, 95% confidence intervals (CI): 64.53, 80.25 months, range 60 to 147 months). The mean weighted implant survival was 97.4% (median 98.15%, 95% CI: 96.29%, 98.54%, range 83.80% to 100%). Cumulative survival rate of implants placed in the mandible was significantly higher than for the maxilla (p < 0.01). No significant difference in failure rate was found among the types of prosthesis employed (p = 0.27). The mean peri-implant bone level change at the end of the follow-up in each study ranged from 0.3 to 1.7 mm. Conclusion: Immediate loading of implants appears to have long-term predictability and success rate under well-defined circumstances.

Implant supported cantilevered fixed dental rehabilitations in partially edentulous patients: Systematic review of the literature. Part I

OBJECTIVES

To investigate in which clinical situations a cantilever fixed implant supported restorations can be a treatment alternative and which complications are reported.

MATERIALS AND METHODS

Two operators screened the literature (MEDLINE, EMBASE) and performed a hand search on the main journals dealing with implantology and prosthetics until 31 December 2017. Only articles that considered cantilever implant fixed restorations with at least 10 patients and with a mean follow-up of at least 5 year were selected. The outcome variables were survival of implants and prosthesis, mechanical, technical and biological complications, marginal bone loss. The review was performed according to the PRISMA statements. Risk of bias assessment was evaluated. Failure and complication rates were analysed using random effect Poisson regression models to obtain summary estimate of 5- and 10-year survival and complication rates.

RESULTS

A total of nine papers were selected for partially edentulous patients and reported high survival rate of the prosthesis. The estimated survival rate for 5-10 years was calculated to be 98.4% for the implants and 99.2% for the rehabilitations. Mechanical, technical and biological complications were reported with a cumulative 5-10 years complication rate of 28.66% and 26.57% for the patients and for the prosthesis, respectively. Two papers for single implant supporting 2-unit cantilever were not sufficient to draw conclusions.

CONCLUSIONS

There is evidence that cantilever can be successful treatment in partially edentulous patients. In two adjacent edentulous sites, data are not yet sufficient.

Evaluation of satisfaction of individuals rehabilitated with zygomatic implants as regards anesthetic and sedative procedure: A prospective cohort study

PURPOSE

To evaluate the satisfaction of individuals with atrophic maxilla, rehabilitated with fixed dental prostheses, anchored on zygomatic implants, with variables being the anesthetic procedure: general anesthesia, or local with sedation.

MATERIALS AND METHODS

By means of the clinical record charts from the Training Course in Advanced Hospital Surgeries for Implant Dentists conducted at the Campinas-SP unit of the São Leopoldo Mandic School of Dentistry, 30 individuals were randomly selected. They had zygomatic implant placement surgeries performed, and were rehabilitated with fixed implant supported complete dentures, between the years 2005 and 2011. One group of 15 individuals underwent surgery in hospital, under general anesthesia. The other 15 were treated in the post-graduation clinic at the School of Dentistry, under local anesthesia and sedation.

RESULTS

From the emotional point of view, the Wilcoxon test revealed that irrespective of the anesthesia procedure used, at the beginning of treatment, the emotional condition of individuals differed from that verified after conclusion of the treatment (p < 0.0001).

CONCLUSION

There was no difference between the two groups as regards the anesthetic procedure. General satisfaction was high; there was emotional improvement after conclusion of the treatment, thus improving the quality of life.