Evaluation of 31 zygomatic implants and 74 regular dental implants used in 16 patients for prosthetic reconstruction of the atrophic maxilla with cross-arch fixed bridges

Round and flat zygomatic implants: effectiveness after a 3‑year follow‑up non‑interventional study

PURPOSE

This non-interventional study investigates variations in the type and frequency of late complications linked to novel zygomatic implant designs, installed adhering to the Zygoma Anatomy-Guided Approach (ZAGA) concept, over an extended follow-up period of at least 3 years.

METHODS

Consecutive patients presenting indications for treatment with ZIs were treated according to ZAGA recommendations. Implants were immediately loaded. The ORIS success criteria for prosthetic offset, stability, sinus changes and soft-tissue status were used to evaluate the outcome.

RESULTS

Twenty patients were treated. Ten patients received two ZIs and regular implants; one received three ZIs plus regular implants, and nine received four ZIs. Fifty-nine ZIs were placed: thirty-six (61%) Straumann ZAGA-Flat implants and twenty-three (39%) Straumann ZAGA-Round implants. Four patients (20%) presented earlier sinus floor discontinuities. Fifteen patients (75%) had prior sinus opacities. Nineteen patients were followed for between 38 and 53 months (mean 46.5 months). One patient dropped out after 20 months. When comparing pre-surgical CBCT with post-surgical CBCT, 84.7% of the sites presented identical or less sinus opacity; nine locations (15%) showed decreased, and another nine increased (15%) post-surgical sinus opacity. Fifty-three ZIs (89.8%) maintained stable soft tissue. Six ZIs had recessions with no signs of infection. ZIs and prosthesis survival rate was 100%.

CONCLUSIONS

The study highlights the effectiveness of ZAGA-based zygomatic implant rehabilitations using Round and Flat designs. Despite patient number constraints, minimal changes in the frequency of late complications from the 1-year follow-up were observed. 100% implant and prosthesis survival rate over a mean follow-up of 46.5 months is reported.

Immediate rehabilitation of severely atrophic maxillae using conventional and extended length subcrestal angulated (ELSA) implants: A retrospective analysis of 187 implants in 33 patients with up to three years of function

PURPOSE

The purpose of this study was to evaluate and determine clinical outcomes and survival rates of straight and extended length subcrestal angulated (ELSA) implants (20-24 mm lengths) placed for immediate (up to 72 h post-operative) or delayed rehabilitation (4 months post-operative) of severely atrophic maxillae. Prosthetic treatment consisted of interim and definitive implant-supported fixed implant-supported prostheses with up to 3 years of function.

MATERIALS AND METHODS

A retrospective analysis was conducted of 38 patients (five dropped out; final total was 33), treated between 2017 and 2019 in a private practice. Extended length subcrestal angulated (ELSA) implants and conventional endosseous straight implants (Southern Implants, Irene, South Africa) with (fixed) full arch prostheses were used to restore patients with edentulous maxillae immediately (within 72 hs) or delayed (4 months).  ELSA implants have subcrestal angulations of 24° and 36° of the restorative platforms, external hexagon crestal anti-rotation abutment connections, and lengths between 18 and 26 mm. Implant loading was determined by implant insertion torque values (as determined on the surgical units); 120 Ncm was the threshold level for immediate loading. Clinical and radiographic examinations were done that recorded the clinical outcomes of implants and prostheses. SPSS was used to process the data.

RESULTS

Thirty-three patients and 187 implants were included with follow-up periods of at least 12 months (range 12-36 months). The mean age of the study population was 62.6 ± 8.4 years old (at the time of implant placement). Thirty-three patients (86.8%) were followed for 12 months; 13 patients (39.4%) were followed for 24-35 months; 9 patients (27.3%) were followed for 36 months. In total, 13 implants in six patients failed secondary to sinus infections. Mean bone levels (MBLs) were respectively: 0.88 ± 2.12 mm at loading, -1.53 ± 2.03 mm at 12 months, -2.26 ± 1.45 mm at 24 months, and -2.54 ± 1.46 mm at 36 months. The ELSA implants showed significantly lower (p = 0.014) MBL at 36 months than did the conventional implants. One hundred thirty-seven implants were placed and loaded within 72 h; 50 implants were placed and loaded 4 months post placement. The combined implant survival rates were 93.0% at 12 months, 91.1% at 24 months, and 100% at 36 months. The ELSA implants showed significantly lower (p = 0.014) MBLs at 36 months when compared to the conventional implants.

CONCLUSIONS

The results of this retrospective clinical chart review indicated that the use of ELSA implants placed into anterior maxillae and nasal crests with accentuated distal tilts (>30°) and simultaneous sinus augmentation provided favorable outcomes for prosthetic rehabilitation in patients with severe atrophic maxillae. ELSA implants placed with simultaneous sinus augmentation are an alternative option to zygomatic implants (ZI) when immediate loading is prescribed. Sinus infections were thought to be the proximate causes of all implant failures. Further long-term clinical studies are warranted with larger patient populations.

Evaluation of Quality of Life and Satisfaction with Fixed Prostheses on Zygomatic Implants vs All-on-Four Concept: A Randomized Clinical Study

AIM

To compare between the rehabilitation of atrophied maxilla with fixed prosthesis using two posterior zygomatic implants and two conventional anterior implants or four implants inserted according to the all-on-four concept regarding the patient quality of life and satisfaction after one year of prosthesis insertion.

MATERIALS AND METHODS

Thirty-six patients with atrophic edentulous maxillae were randomized into two groups: Group I (rehabilitated with fixed prostheses supported by two zygomatic and two conventional implants in the anterior region) and group II (fixed prostheses on four implants in the anterior region following an all-on-four concept). One year after the placement of the definitive prostheses, patients completed oral health impact profile-14 and satisfaction questionnaires.

RESULTS

All patients were satisfied regarding retention, stability, occlusion, comfort, cleaning, speaking, chewing, bolus quality, appearance, handling, prosthesis apart, and embarrassing, with no significant significance between two groups except satisfaction with surgical procedures and healing period.

CONCLUSIONS

Using two distally tilted zygomatic implants or all-on-four concept to rehabilitate atrophied maxilla by fixed detachable prosthesis could be considered a promising functional and esthetic treatment option regarding the patient satisfaction.

CLINICAL SIGNIFICANCE

Traditionally, treatment of maxillary atrophied ridges was done by bone grafting or sinus-lifting techniques; however, using all-on-four concept or zygomatic implants was a successful treatment as it has high success rates and highly satisfied by the patients. How to cite this article: Nagib MA, Ibrahim AM, Abdel-Rahman FH, et al. Evaluation of Quality of Life and Satisfaction with Fixed Prostheses on Zygomatic Implants vs All-on-Four Concept: A Randomized Clinical Study. J Contemp Dent Pract 2024;25(2):141-147.

Longitudinal reactions of maxillary sinus in patients treated with multiple zygomatic implants: A modified radiographic evaluation with clinical follow-up

OBJECTIVES

To investigate the effects of zygomatic implant placement on the maxillary sinus using radiographic and clinical indicators.

METHODS

Patients with an atrophic maxilla who underwent zygomatic implant placement were included. The thickness and morphology of the Schneiderian membrane (SM), infundibular obstruction, and posterior bone wall of the maxillary sinus were analyzed. The generalized estimating equation and chi-square tests were performed to compare the measurements.

RESULTS

Fifty patients with 100 maxillary sinuses were included. In total, 148 zygomatic implants and 105 regular implants were placed in the maxilla. Overall, the mean pre- and postoperative SM thickness was 2.79 ± 3.26 mm and 3.97 ± 5.45 mm, respectively (p = 0.063). In sinuses with two zygomatic implants, the SM thickness increased significantly from 2.12 ± 2.14 mm preoperatively to 4.07 ± 6.14 mm postoperatively (p = 0.026). The number of sinuses with type IV morphology (fully radiopaque) increased from zero preoperatively to six (13%) postoperatively. Sinuses with a single zygomatic implant showed no difference in the pre- and postoperative SM thickness. Postoperatively, six sinuses had infundibulum obstructions. Postoperative osteitis of the bilateral sinuses was found in two patients.

CONCLUSIONS

We have proposed a new imaging evaluation method and system for evaluating the maxillary sinus response. Preoperative infundibulum obstruction combined with mucosal thickening and double zygomatic implant placement are more likely to induce postoperative maxillary sinus mucositis and osteitis.

The Zygomatic Anatomy-Guided Approach, Zygomatic Orbital Floor Classification, and ORIS Criteria-A 10-Year Follow-Up

BACKGROUND

Presently, the management of patients with maxilla bone defects of the Cawood V or VI class is achieved using zygomatic or individual implants or through augmentation of the bone. For zygomatic implants, the ORIS criteria represent the most common factor in helping practitioners register success rates. The zygomatic anatomy-guided approach (ZAGA)and zygomatic orbital floor (ZOF) are factors that are crucial to examining the anatomy of a particular patient before the procedure. The aim of thisarticle is to find the statistical relationship between the abovementioned terms and other factors.

METHODS

A total of 81 patients underwent zygomatic implant procedures in different configurations. The ORIS, ZAGA, and ZOF parameters were compared with other factors such as type of surgery, sex, age, and the anatomy of the zygomatic bone.

RESULTS

Most patients in this article were classified as ZAGA Class 2. The relationships between type of surgery and ZAGA classification, and ZAGA and sinus/maxilla zygomatic implant localization were statistically significant.

CONCLUSIONS

The ZAGA and ZOF scales are practical and valuable factors that should be taken into account before surgery, whereas to date, criteria better than the ORIS scale have not been described in terms of the success of zygomatic implants. The ZOF scale might omit perforation of the orbit because this parameter warns a practitioner to be aware of the anatomy of the orbit.

Hygienic maintenance in patients with maxillae atrophy and in oncological patients with maxillary resection rehabilitated with zygomatic implants: A nested monocentric prospective cohort study

OBJECTIVE

To assess peri-implant soft tissues condition, comparing clinical parameters of implants placed in patients with atrophic upper jaws and patients who underwent maxillary resection for oncological reasons.

BACKGROUND

Zygomatic implants (ZIs) in oncologic patients could be affected by more complications compared to implants placed in atrophic maxillae. The soft tissue condition is an essential requirement for implant success, but few studies have investigated this topic.

METHODS

A nested monocentric prospective parallel cohort (atrophic vs. oncological patients) study was performed. Clinical visits and professional hygiene sessions were performed every three months, and bleeding on probing (BOP), probing pocket depth (PPD), gingival index (GI), plaque index (PI) and implant mobility were recorded by a blind outcome assessor.

RESULTS

In total, 77 ZIs placed in 21 patients were evaluated: 54 (70.1%) ZIs were inserted in patients belonging to the atrophic cohort (PAM) and 23 (29.9%) ZIs in the oncologic cohort (OP). The probability of having BOP at the considered mean follow-up (27 months) was 24.8% (95% CI 19.0-31.9) for PAM and 22.9% (95% CI 15.1-33.9) OP. The mean PPD values were 2.78 ± 1.28 (range 1-8) in PAM and 2.91 ± 1.98 (range 0-10) in OP. None of the implants showed mobility. No associations between group belongingness and the entity of PPD, PI, GI and the risk of BOP were found, adjusting for the considered confounding factors (age, smoking and implant position).

CONCLUSIONS

Under a strict supportive hygiene therapy protocol ZIs in oncologic patients showed similar peri-implant tissue conditions to that of patients with maxillary atrophy.

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.

Evaluation of surgical techniques in survival rate and complications of zygomatic implants for the rehabilitation of the atrophic edentulous maxilla: a systematic review

PURPOSE

To assess the outcome [zygomatic implant (ZI) survival] and complications of the original surgical technique (OST) and an Anatomy-Guided approach (AGA) in the placement of ZI in patients with severely atrophic maxillae.

METHODS

Two independent reviewers conducted an electronic literature search from January 2000 to August 2022. The inclusion criteria were articles reporting at least five patients with severely atrophic edentulous maxilla undergoing placement OST and/or AGA, with a minimum of 6 months of follow-up. Number of patients, defect characteristics, number of ZI, implant details, surgical technique, survival rate, loading protocol, prosthetic rehabilitation, complications, and follow-up period were compared.

RESULTS

Twenty-four studies comprised 2194 ZI in 918 patients with 41 failures. The ZI survival rate was 90.3-100% in OST and 90.4-100% in AGA. Probability of complications with ZI with OST was as follows: sinusitis, 9.53%; soft tissue infection, 7.50%; paresthesia, 10.78%; oroantral fistulas, 4.58%; and direct surgical complication, 6.91%. With AGA, the presenting complications were as follows: sinusitis, 4.39%; soft tissue infection, 4.35%; paresthesia, 0.55%; oroantral fistulas, 1.71%; and direct surgical complication, 1.60%. The prevalence of immediate loading protocol was 22.3% in OST and 89.6% in the AGA. Due to the heterogeneity of studies, statistical comparison was only possible after the descriptive analysis.

CONCLUSIONS

Based on the current systematic review, placing ZI in severely atrophic edentulous maxillae rehabilitation with the OST and AGA is associated with a high implant survival rate and surgical complications within a minimum of 6 months follow-up. Complications, including sinusitis and soft tissue infection around the implant, are the most common. The utilization of immediate loading protocol is more observed in AGA than in OST.

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.

Survival of conventional dental implants in the edentulous atrophic maxilla in combination with zygomatic implants: a 20-year retrospective study

PURPOSE

Implant-supported prosthetic rehabilitation in the resorbed maxilla is a great challenge. The aim of this study was to determine the survival rate of conventional anterior implants placed in combination with zygomatic implants according to the Brånemark technique, and to identify risk factors for implant failure.

METHODS

We collected data retrospectively from 72 consecutive patients who received treatment from 1998 to 2018 at our center, according to Brånemark's original technique. Kaplan-Meier analysis was conducted to assess survival rate, and a survival regression model was used with the patient as the random factor, applying the Weibull distribution.

RESULTS

A total of 236 maxillary anterior implants were included, with a mean follow-up of 12.1 years. Kaplan-Meier analysis showed overall cumulative survival rates of 95.3% at 1 year, 94.8% at 2 years, 93.0% at 5 years, 90.5% at 10 years, 81.6% at 15 years, and 67.7% at 20 years. Survival regression showed an association between bruxism and implant failure as well as implants bearing an overdenture. Implants with length ≤ 10 mm had a significantly lower survival time. No significant association was found between the number of anterior implants and survival rate.

CONCLUSIONS

We found acceptable long-term anterior conventional implant survival. Significant risk factors for failure were bruxism, overdentures, and implants shorter than 10 mm.

Effect of vitamin B complex administration on pain and sensory problems related to inferior alveolar nerve damage following mandibular implant placement surgery

Background. Inferior alveolar nerve damage can lead to mild to severe paresthesia and even facial pain. One of the treatments considered today for the reconstruction and treatment of damaged peripheral nerves is the use of vitamin supplements. This study aimed to evaluate the effect of vitamin B complex supplementation on pain and sensory problems following mandibular implant placement surgery. Methods. In this single-blind clinical trial, 46 patients applying for implant placement, who were eligible for the study, were evaluated. All the patients were examined for sensory facial injury and inferior alveolar nerve injury within 24 hours after implant placement. The nerve damage was recorded by AI (asymmetry index) in the initial examination. Patients who reported clinical and radiographic signs of nerve damage due to implant or drill impingement of the nerve canal were excluded from the study and promptly treated with anti-inflammatory protocols. Then the patients were randomly divided into control (n=23) and intervention (n=23) groups. Patients in the control group received routine treatment after implantation, and patients in the intervention group received vitamin B complex pills in addition to routine treatment. A placebo was used to eliminate the inductive effect of the drug in the control group. Follow-up of patients was performed at intervals of 14 days and 1, 2, and 3 months after treatment. Data analysis was performed using SPSS 24 and Kruskal-Wallis, Wilcoxon, and chi-squared tests. Results. In both groups, a decreasing trend in pain intensity was observed for up to three months. There were no significant differences between the mean pain intensity in the intervention and control groups at all the follow-up intervals. In both groups, a decrease in the rate of paresthesia was observed during the 3-month follow-up. The mean of paresthesia in the two groups was not significantly different at any follow-up interval. Conclusion. Vitamin B complex might not affect pain intensity and paresthesia after implant surgery.

Maxillary Sinusitis as a Complication of Zygomatic Implants Placement: A Narrative Review

Aims: The aim of this review is to consider maxillary sinusitis as a complication of zygomatic implants placements. Maxillary sinusitis a common complication but in the literature there are no reviews that focus only on this condition and its possible treatment. This review was carried out with to highlight the main findings of the literature on this topic and to improve knowledge in this field. Methods: The search strategy resulted in 155 papers. After selection of the inclusion criteria only 11 papers were examined. From the papers these, 12.3% patients presented maxillary sinusitis but only four studies evaluated sinusitis (both clinical and radiological evaluation). The most common treatment used by the authors were antibiotics alone or combined with functional endoscopic sinus surgery (FESS). Results: The literature shows an absence of precise and shared guidelines diagnosis and post-operative follow-up, and of the treatment of maxillary sinusitis following zygomatic implantology. It has not been determined if the surgical placement of ZIs is better than the other techniques for treatment of the onset of maxillary sinusitis in the post-operative period. Conclusion: To date there are no shared protocols for maxillary sinusitis treatment. In our experience, and according to the literature in the presence of risk factors such as age, comorbidities, smoking, nasal septal deviation or other anatomical variants, we suggested that FESS is performed at the same time as placement of zygomatic implants.

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.

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.

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.

Zygomatic implants placed in atrophic maxilla: an overview of current systematic reviews and meta-analysis

BACKGROUND

Zygomatic implants are a treatment option for severely atrophic maxilla.

MAIN TEXT

This study aimed to summarize and evaluate systematic reviews assessing the clinical outcomes of zygomatic implants including survival/failure rate and complications. PubMed-MEDLINE, Google Scholar, LILACS, and the Cochrane Database were searched up to April 2020. Risk of bias assessment was conducted by the AMSTAR tool. Initial searches yielded 175 studies. These were assessed, and following title abstract and full-text evaluation, 7 studies (2 meta-analyses) were included in the final review. According to the AMSTAR tool, 1 was deemed high quality, 4 were classified as medium, and 2 as low quality. The mean AMSTAR score (±SD) was 5.28 of 9 (±2.36) ranging from 2/9 to 9/9. The reported survival rates ranged from 95.2 to 100% except for resected maxillas, which established higher failure rates up to 21.43%. Concerning the complications with the zygomatic implants, various surgical and prosthetic complications were reported with sinusitis being the most frequently observed complication. Zygomatic implants appears to offer a promising alternative to formal bone grafting techniques with lower costs, less complications, less morbidity, shorter treatment times, and comparably high survival rates.

CONCLUSION

Complications were rare and usually easy to manage. However, the treatment should be directed by appropriately trained clinicians with noticeable surgical experience.

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.

Maxillofacial Rehabilitation With Zygomatic Implants in an Oncologic Patient: A Case Report

Tumor ablation results in significant sequelae in the appearance, function, and esthetics of a patient with cancer, especially resection for head and neck cancer. Reconstruction with local and microvascular flaps is a workable option; however, the esthetic results will occasionally be unfulfilling and inadequate for the rehabilitation of lost structures. Prosthetic rehabilitation with conventional and zygomatic implants can provide favorable and predictable long-term results. We report the clinical case of a 53-year-old female patient with adenoid cystic carcinoma (ACC). The treatment protocol included radical surgery, radiotherapy, and maxillofacial rehabilitation with conventional and zygomatic implants. Management of an ACC case requires a timely, radical, and multidisciplinary approach. In our patient, rehabilitation of masticatory function was accomplished in the immediate postoperative period and before radiotherapy. The rehabilitation of masticatory function improved the patient's systemic and nutritional status and her speech, with coverage of the esthetic defect. These outcomes reduced the psychological and emotional effects of tumor ablation.

Does Middle Meatal Antrostomy Prevent the Onset of Maxillary Sinusitis After Zygomatic Implant Placement?

PURPOSE

To evaluate the role of middle meatal antrostomy in preventing the onset of maxillary sinusitis after placement of zygomatic implants. We hypothesized that middle meatal antrostomy might reduce the incidence of this complication.

MATERIALS AND METHODS

A prospective longitudinal study was performed of patients who had undergone placement of 4 zygomatic implants and concurrent middle meatal antrostomy with an endoscopic approach at the maxillofacial surgery unit of Verona University. The radiological results of the maxillary sinuses were evaluated on computed tomography scans performed 12 months after surgery using the Lund-Mackay staging system. Clinical symptoms were evaluated both preoperatively and 12 months after surgery using the Sino-Nasal Outcome Test-20 (SNOT-20). Intraoperative violation of the Schneiderian membrane was also assessed. The outcomes from the present study were compared with historical controls.

RESULTS

The sample included 13 patients, 26 maxillary sinuses with negative radiologic findings of sinonasal pathologic features, and 52 zygomatic implants. A moderate increase was found in radiologic findings of sinonasal pathologic features postoperatively compared with preoperatively, with mucosal hypertrophy in 3 maxillary sinuses (11.5%). The incidence and severity of mucosal hypertrophy was significantly lower than the outcomes of the historical controls. The average preoperative SNOT-20 score was 13.45, and the postoperative SNOT-20 score was 1.18. The Schneiderian membrane was pierced in 13 sinuses in 9 patients.

CONCLUSIONS

Shrinkage of the ostiomeatal complex seems to play a fundamental role in the onset of sinonasal pathologic features after zygomatic implant placement compared with implant-related causes. Although functional endoscopic sinus surgery is a supplementary surgical method in implant placement, it seems to provide statistically significant improvement in the health of the sinonasal system. Perforation of the Schneiderian membrane does not appear to correlate with the onset of sinus opacification and sinonasal symptoms.

Extra-Sinus Zygomatic Implants to Avoid Chronic Sinusitis and Prosthetic Arch Malposition: 12 Years of Experience

This report retrospectively at the 12-year follow-up results of the treatment and rehabilitation of edentulous maxillae, applying extra-sinus zygomatic implants alone or in combination with intra-sinus zygomatic implants. We recruited 22 patients with 35 zygomatic Brånemark system implants; 24 implants in the standard Brånemark protocol through the sinus and 11 extra-sinus implants outside the sinus. Additionally, 147 regular implants were placed. The minimum follow-up period was 50 months to a maximum of 152 months. The zygoma survival rate after 12 years was 97.15%. Chronic sinusitis occurred in 11.42% of patients. We lost 1 (2.85%) zygomatic implant placed through the sinus and none of those in the extra-sinus position. The survival rate of the regular implants was 93.87%. Chronic sinusitis occurred in 4 patients (11.42%) who received zygomatic implants using standard protocol through the sinus. None of the extra-sinus zygoma patients developed sinusitis. Peri-implantitis was detected with only 3 zygomatic implants. In the original P-I Brånemark zygoma protocol the implants were passing through the sinus, which resulted in chronic sinusitis in some patients and malposition of the prosthetic platform toward the palate. These complications can be avoided by the extra-sinus placement of zygoma implants as demonstrated in this study.

Long-term Schneiderian membrane thickness changes following zygomatic implant placement: A retrospective radiographic analysis using cone beam computed tomography

OBJECTIVES

The purpose of this retrospective study was to evaluate the long-term changes in the thickness of Schneiderian membranes after zygomatic implant placement using cone beam computed tomography (CBCT).

MATERIAL AND METHODS

Twenty-five consecutive patients were included in this study. All the patients underwent bilateral zygomatic implant placement. Schneiderian membrane thickness (SMT) in 49 maxillary sinuses (one sinus was not included because of early loss of the zygomatic implants) was measured using CBCT before and at least 1 year after zygomatic implant placement. Ostium patency of each sinus was also evaluated and recorded.

RESULTS

In total, 84 zygomatic implants and 30 regular implants were placed in included patients. Two unilateral maxillary zygomatic implants in one patient were removed 2 months after implant placement. The SMT increased from 1.03 mm (inter-quartile range: 1.57 mm) to 1.33 mm (inter-quartile range: 1.98 mm) after a median follow-up time of 23.00 months (inter-quartile range: 14 months), and the difference was statistically significant. Before zygomatic implant insertion, 24.5% (12/49) of sinuses had SMT greater than 2 mm, whereas this value was 28.6% (14/49) after zygomatic implant placement. The percentage of sinuses observed with ostium patency also increased from 2.0% (1/49) to 12.2% (6/49).

CONCLUSIONS

Chronic Schneiderian membrane thickening could result from zygomatic implant insertion. Intensive postoperative care and clinical and radiographic monitoring are recommended after zygomatic implant placement.

Avaliação da satisfação de reabilitações com implantes zigomáticos

Resumo Introdução A reabilitação oral de pacientes com atrofia óssea maxilar representa um grande desafio por estes pacientes apresentarem comprometimento da qualidade de vida, dificuldades alimentares, complicações nutricionais, dificuldades sociais e emocionais. Propostas de reabilitações de maxilas mutiladas e/ou atróficas com próteses totais fixas implantossuportadas, utilizando implantes zigomáticos, foram relatadas. Objetivo O objetivo deste estudo foi avaliar o grau de satisfação dos pacientes reabilitados com implantes zigomáticos e convencionais, em função de carga imediata com prótese do tipo protocolo através de um estudo retrospectivo, por meio de questionário respondido pelos pacientes. Material e método Foram incluídos dezenove pacientes, tratados na clínica do Instituto Latino Americano de Pesquisa e Ensino Odontológico (ILAPEO) em Curitiba, PR (Brasil), entre dezembro de 2005 e junho de 2010. Os pacientes foram reabilitados com 41 implantes zigomáticos e 73 implantes convencionais, todos do tipo cone Morse. As próteses, tipo híbridas, foram instaladas em carga imediata. Resultado O índice de satisfação encontrado foi de 100%. Conclusão Pode-se concluir que esta técnica de reabilitação restabelece fatores primordiais ao ser humano como mastigação, fonética e estética. Os pacientes relataram satisfação com o resultado do tratamento, conseguindo desenvolver atividades sociais dentro da normalidade, elevando sua autoestima.

Evaluation of Clinical Soft Tissue Parameters for Extramaxillary Zygomatic Implants and Conventional Implants in All-on-4 Hybrid Rehabilitations: Short-Term Outcome and Proposal of Clinical Recommendations for Intervention in Recall Appointments

PURPOSE

This prospective cohort study aimed to investigate the short-term soft tissue clinical outcomes and recommendation for evaluation and follow-up after a new hybrid All-on-4 rehabilitation.

METHODS

Forty consecutively included patients rehabilitated in the complete edentulous atrophic maxillae through a hybrid All-on-4 treatment concept (4 immediate function implants in a combination between zygomatic and conventional implants). Periimplant conditions at zygomatic and conventional implants were compared. Four clinical levels (CLs) were used to classify the presence and severity of periimplant conditions.

RESULTS

Four patients withdrew from the study. No significant differences were found for periimplant conditions at zygomatic and conventional implants. The distribution was 28, 2, 1, and 9 patients with CL1, CL2, CL3, and CL4, respectively.

CONCLUSIONS

Soft tissue clinical outcomes of extramaxillary zygomatic implants and conventional implants seem to follow a similar distribution. The proposed classification system stratifies patients, supports decision making, and with further validation may elucidate recommendations for frequency of recall appointments and intervention to enhance long-term success.

Surgical complications in zygomatic implants: A systematic review

BACKGROUND

The use of zygomatic implants in the prosthetic rehabilitation of the patient with severe maxillary bone atrophy is another therapeutic alternative, not exempt from complications. The main objective of this review is to analyze and describe the most frequent surgical complications associated with the use of zygomatic implants.

MATERIAL AND METHODS

An electronic database search on PubMed, along with a manual search, without taking into account date nor language, was undertaken by two observers, selecting studies that comprised a study period from 6 to 12 months, any type of clinical trial, and series that included a follow-up and/or review period during the aforementioned margin, that mentioned at least two types of complications.

RESULTS

Out of the initial search that yielded 455 studies, 67 were considered potentially relevant for the present study, out of which 14 were finally selected. Out of the most frequent surgical complications, sinusitis (3,9%) and failure in osseointegration (2,44%) are highlighted.

CONCLUSIONS

The analysis of the results shows that the most frequent complications are sinusitis and failure in osseointegration of the zygomatic implant. However, a standardised data collection system for the data on complications is needed.

Zygomatic implants: indications, techniques and outcomes, and the zygomatic success code

The zygoma implant has been an effective option in the management of the atrophic edentulous maxilla as well as for maxillectomy defects. Brånemark introduced the zygoma implant not only as a solution to obtain posterior maxillary anchorage but also to expedite the rehabilitation process. The zygoma implant is a therapeutic option that deserves consideration in the treatment-planting process. This paper reviews the indications for zygoma implants and the surgical and prosthetic techniques (including new developments) and also reports on the clinical outcome of the zygomatic anatomy-guided approach. An overview of conventional grafting procedures is also included. Finally, a Zygoma Success Code, describing specific criteria to score the success of rehabilitation anchored on zygomatic implants, is proposed.

Survival and Complications of Zygomatic Implants: An Updated Systematic Review

PURPOSE

To assess the survival rate of zygomatic implants (ZIs) and the prevalence of complications based on previously published studies.

MATERIALS AND METHODS

An electronic search of 3 databases was performed in December 2015 and was supplemented by manual searching. Clinical series of ZIs were included. Interval survival rate and cumulative survival rate (CSR) were calculated. The untransformed proportion of complications (sinusitis, soft tissue infection, paresthesia, oroantral fistulas) was calculated by considering the prevalence reported in the studies.

RESULTS

Sixty-eight studies were included, comprising 4,556 ZIs in 2,161 patients with 103 failures. The 12-year CSR was 95.21%. Most failures were detected within the 6-month postsurgical period. Studies (n = 26) that exclusively evaluated immediate loading showed a statistically lower ZI failure rate than studies (n = 34) evaluating delayed loading protocols (P = .003). Studies (n = 5) evaluating ZIs for the rehabilitation of patients after maxillary resections presented lower survival rates. The probability of presenting postoperative complications with ZIs was as follows: sinusitis, 2.4% (95% confidence interval [CI], 1.8-3.0); soft tissue infection, 2.0% (95% CI, 1.2-2.8); paresthesia, 1.0% (95% CI, 0.5-1.4); and oroantral fistulas, 0.4% (95% CI, 0.1-0.6). However, these numbers might be underestimated, because many studies failed to mention the prevalence of these complications.

CONCLUSION

ZIs present a high 12-year CSR, with most failures occurring at the early stages postoperatively. The main observed complication related to ZIs was sinusitis, which can appear several years after ZI installation surgery.

Influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient satisfaction

Background

To assess the influence of the prosthetic arm length (palatal position) of zygomatic implants upon patient comfort and stability, speech, functionality and overall satisfaction.

Material and Methods

A retrospective clinical study was made of patients subjected to rehabilitation of atrophic maxilla with complete maxillary implant-supported fixed prostheses involving a minimum of two zygomatic implants (one on each side) in conjunction with premaxillary implants, and with 12 months of follow-up after implant loading. Subjects used a VAS to score general satisfaction, comfort and stability, speech and functionality, and the results were analyzed in relation to the prosthetic arm length of the zygomatic implants 12 months after prosthetic delivery.

Results

Twenty-two patients participated in the study, receiving 22 prostheses anchored on 148 implants (44 were zygomatic and 94 were conventional implants). The mean right and left prosthetic arm length was 5.9±2.4 mm and 6.1±2.7 mm, respectively, with no statistically significant differences between them (p=0.576). The mean scores referred to comfort/retention, speech, functionality and overall satisfaction were high - no correlation being found between prosthetic arm length and patient satisfaction (p=0.815).

Conclusions

No relationship could be identified between prosthetic arm length (palatal position) and patient satisfaction.

Key words:Zygomatic implants, patient satisfaction, zygomatic prosthesis, prosthetic arm length.

Are Zygomatic Implants Associated With Maxillary Sinusitis?

PURPOSE

The purpose of the present study was to analyze the relation between zygomatic implants and symptomatic and radiologic modifications of the maxillary sinuses.

MATERIALS AND METHODS

A retrospective cohort study of patients who underwent zygomatic implant rehabilitation at the Clinic of Dentistry and Maxillofacial Surgery of the University of Verona from January 2005 through May 2014 was designed. The primary predictor variable was time (pre- vs postoperative). Concerning outcome variables, radiologic findings of thickened mucosa or opacification of the maxillary sinuses were evaluated on computed tomograms using the Lund-Mackay Staging System. Clinical symptoms were evaluated using the Sino-Nasal Outcome Test-20 (SNOT-20). The parameters assessed underwent descriptive statistical analysis.

RESULTS

The sample was composed of 41 patients (mean age, 54 yr; 61% women). Preoperatively, 12% had sinus findings. Postoperatively, 46% had sinus findings (P = .0001 by McNemar paired test). Preoperatively, 12% had a SNOT-20 score higher than 11. Postoperatively, 15% had a SNOT-20 score higher than 11 (P = 1 by McNemar paired test).

CONCLUSIONS

In accordance with data in the literature data, placement of zygomatic implants does not seem to be associated with severe rhinosinusitis complications. However, in a considerable number of patients, asymptomatic radiologic alterations of the paranasal sinuses were observed. Therefore, it is important to plan assessments of the prosthetic and peri-implant components of the procedure and the postoperative homeostasis of the maxillary sinuses.

Rehabilitation with 4 zygomatic implants with a new surgical protocol using ultrasonic technique

When the residual bone crest cannot allow the placement of standard implants, the treatment for complete arch rehabilitation of severely atrophic maxillae can be performed with 4 zygomatic implants (ZIs) and immediate function with predictable results in terms of aesthetics, function, and comfort for the patient. However, even if ZIs' rehabilitations showed a good success rate, this surgery is difficult and need a skillful operator. Complications in this kind of rehabilitation are not uncommon; the main difficulties can be related to the reduced surgical visibility and instrument control in a critical anatomic area. All the surgical protocols described in the literature used drilling techniques. Furthermore, the use of ultrasonic instruments in implant surgery compared with drilling instruments have shown advantages in many aspects of surgical procedures, tissues management, enhancement of control, surgical visualization, and healing. The aim of this study was to report on the preliminary experience using ultrasound technique for ZIs surgery in terms of safety and technical improvement. Ten consecutive patients with severely atrophic maxilla have been treated with 4 ZIs and immediate complete arch acrylic resin provisional prostheses. The patients were followed up from 30 to 32 months evaluating implant success, prosthetic success, and patient satisfaction with a questionnaire. No implants were lost during the study period, with a 100% implant and prosthetic success rate. Within the limitations of this preliminary study, these data indicate that ultrasonic implant site preparation for ZIs can be a good alternative to the drilling technique and an improvement for the surgeon.

Closure of oroantral communication with buccal fat pad after removing bilateral failed zygomatic implants: A case report and 6-month follow-up

The aim of this study was to assess the use of buccal fat pad (BFP) technique as an option to close oroantral communications (OAC) after removing failed zygomatic implants in a patient with a severely resorbed maxilla, and to determine the degree of patient satisfaction. A 64-year-old woman presented recurrent sinusitis and permanent oroantral communication caused by bilateral failed zygomatic implants, 3 years after prosthetic loading. Zygomatic implants were removed previous antibiotic treatment and the BFP flap technique was used to treat the OAC and maxillary defect. The degree of patient satisfaction after treatment was assessed through a visual analogue scale (VAS). At 6-months follow-up, patient showed complete healing and good function and the results in terms of phonetics, aesthetics and chewing were highly rated by the patient. Key words:Bichat fat pad, buccal fat pad, zygomatic implants, oroantral communication.

Finite element analysis of three zygomatic implant techniques for the severely atrophic edentulous maxilla

STATEMENT OF PROBLEM

A variety of zygomatic implantation techniques currently exist; however, a consensus regarding the most suitable method has not yet been reached.

PURPOSE

The purpose of this study was to evaluate and compare 3 zygomatic implantation techniques and to clarify the optimal number and position of zygomatic and dental implants for the reconstruction of the severely atrophied edentulous maxilla.

MATERIAL AND METHODS

A 3-dimensional finite element analysis craniofacial model was constructed from the computed tomography data of a selected patient with a severely atrophic edentulous maxilla. Modeled zygomatic implants were inserted into the craniofacial model with 3 surgical techniques (classic Brånemark, exteriorized, and extramaxillary), and with 3 model variations that involved the number and position of zygomatic and dental implants. The zygomatic implants were loaded with a vertical force of 150 N and a lateral force of 50 N. The stresses on and deformations of the bones and implants were then observed and compared.

RESULTS

No obvious differences in the amount and distribution of stress on the external craniofacial bones were detected in the models. The lowest stresses on the zygomatic implants were observed in the exteriorized technique group. The lowest deformations of the bone that surrounds zygomatic implants and dental implants were observed in the exteriorized technique and classic Brånemark technique groups. For the exteriorized technique group, the model with 1 dental implant in the site of the maxillary lateral incisor exhibited the lowest stress on the zygomatic implants and the least deformation of the bone surrounding the zygomatic and dental implants.

CONCLUSIONS

All 3 zygomatic implant techniques resulted in more or less homogeneous transference of force and thus could reconstruct the edentulous maxilla; however, the exteriorized technique with 1 dental implant in the lateral incisor appeared to be the most appropriate reconstruction method for the severely atrophied edentulous maxilla.

Survival and complications of zygomatic implants: a systematic review

PURPOSE

This systematic review attempted to answer the focused questions: "What is the survival rate of zygomatic implants (ZIs)?" and "What are the most common complications related to surgery of zygomatic implants?"

METHODS

An electronic search without date or language restrictions was undertaken in PubMed in March 2012. Titles and abstracts from these results (n = 123) were read for identifying studies that meet the eligibility criteria. Eligibility criteria included studies reporting clinical series of zygomatic implants (ZIs). Because of the scarcity of articles with high-level grades of evidence, all articles, including studies with few case reports, were considered for inclusion. All reference lists of the selected and review studies were hand-searched for additional papers that might meet the eligibility criteria. Simple case report articles were not included. Review articles without original data were excluded. Quantitative data extracted from the included studies that provided data for the period of failure of ZIs were used for the calculation of interval survival rate during each follow-up period and cumulative survival rate (CSR) over a 12-year period.

RESULTS

Thirty-seven studies were identified without repetition and five more studies were included by hand-searching, giving a total of 42; 12 evaluated the use of ZI applied with immediate function protocols and 3 for rehabilitating patients after maxillary resections for tumor ablations. These latter three studies showed smaller ZI success. Postoperative complications reported were as follows: 70 cases of sinusitis, 48 of soft tissue infection, 15 of paresthesia, and 17 cases of oroantral fistulas. However, this number may be underestimated, since most of the studies did not mention the presence or absence of these complications. Most ZI failures were detected at the abutment connection phase (6 months after the surgery of implant placement) or before. The CSR over a 12-year period was 96.7 %.

CONCLUSIONS

Despite the high survival rate observed, there is an impending need for conducting randomized controlled clinical trials to test the efficacy of these implants in comparison with the other techniques to treat the atrophic maxilla. Thus, the findings reported in the review must be interpreted with considerable caution. Moreover, more studies with longer follow-up periods involving adequate number of ZIs are needed. This will help to obtain a better understanding of the survival of ZIs in a long term. It is suggested that multicenter, randomized controlled clinical trials and longer clinical studies should be implemented in this area, before recommending routine use of ZIs for patients could be given. The placement of zygomatic implants requires very experienced surgeons because it is not risk free since delicate anatomic structures such as the orbita and brain may be involved.

Rehabilitation of posterior maxilla with zygomatic and dental implant after tumor resection: a case report

Zygomatic implants have been used for dental rehabilitation in patients with insufficient bone in the posterior upper jaw, due to, for example, tumor resection, trauma, or atrophy. Zygomatic implants are an alternative to complex free or vascularized bone grafting and distraction osteogenesis. A 42-year-old male patient with a severe defect in the right posterior maxilla, starting from the first canine region, which had occurred after tumor resection 3 years earlier, was referred to our department. One zygomatic implant (Brenemark System, Nobel Biocare, Goteborg, Sweden) to the zygoma and one dental implant to the canine region were placed. After a 5-month osseointegration period, a fixed denture was fabricated and adapted to the implants. Although the surgical and prosthetic procedures for zygoma implants are not easy, the final outcomes can be successful with appropriate planning.

Zygomatic implants placed using the zygomatic anatomy-guided approach versus the classical technique: a proposed system to report rhinosinusitis diagnosis

PURPOSE

The first aim of this study is to compare the outcomes in rehabilitating the atrophic maxilla using zygomatic implants (ZIs) and regular implants (RIs) using the classical zygomatic technique (CZT) versus the zygomatic anatomy-guided approach (ZAGA). The second goal of this paper is to propose a standardized system to report rhinosinusitis diagnosis.

MATERIALS AND METHODS

Twenty-two consecutive zygomatic patients operated on from 1998 to 2002 and 80 consecutive zygomatic patients operated on from 2004 to October 2009 were selected. All included patients were in a maintenance program. Survival rates (SRs) of ZI and RI were recorded. Implants were individually tested using Periotest® (Periotest value [PTv], Siemens AG, Bensheim, UK). Sinus health was radiographically and clinically assessed according to Lund-Mackay system and Lanza and Kennedy survey recommended by Task Force on Rhinosinusitis for research outcomes. A satisfaction questionnaire (Oral Health Impact Profile for assessing health-related quality of life in Edentulous adults) and different anatomical measurements were also performed.

RESULTS

No significant differences (p = .602) were observed with respect to SR between the two groups (95.12% vs 96.79%). Significant differences (p = .000) were found comparing measurements of ZI head distance to the alveolar crest (5.12 ± 2.38 mm vs 2.92 ± 2.30 mm). With the CZT, more palatal emergence of ZI was observed. PTv gave significantly greater stability for the CZT compared with the ZAGA group in both measurements (-4.38 ± 1.75 vs -2.49 ± 4.31, p = .000; -4.94 ± 1.46 vs -3.11 ± 5.06, p = .000). Lund-Mackay score was significantly lower for the ZAGA group (2.38 ± 3.86 vs 0.56 ± 1.26, p = .042). Statistically significant difference (p = .047) regarding the percentage of patients with no signs or symptoms of rhinosinusitis (Lanza and Kennedy test negative and Lund-Mackay score zero) was observed between groups (54.55% vs 76.25%, p = .047).

CONCLUSIONS

Both procedures had similar clinical outcomes with respect to implant survival. The ZAGA concept is able to immediately rehabilitate the severely atrophic maxillae, minimizing the risk of maxillary sinus-associated pathology. Moreover, less bulky, more comfortable, and easy to clean prostheses are achieved.

Rehabilitation of Atrophic Posterior Maxilla With Zygomatic Implants: Review

The objective of this study was to review the published literature to evaluate treatment success with zygomatic implants in patients with atrophic posterior maxilla. Studies from 1987 to 2010 were reviewed. In each study, the following were assessed: indications for treatment, number of patients, number of implants, length and diameter of the implants, surgical technique, prosthetic rehabilitation, success rate, complications, and patient satisfaction. Sixteen studies were included, with a total of 941 zygomatic implants placed in 486 patients. The follow-up periods ranged from 12 to 120 months. Three different surgical techniques were used to place zygomatic implants: intrasinus implants with the classic sinus window technique, the sinus slot technique, and extrasinus zygomatic implants. The most common restoration used was fixed prosthesis, with either delayed loading after 3–6 months (89%–100% success) or immediate loading (96.37%–100% success). The weighted average success rate was 97.05%, and the most frequent complication was maxillary sinusitis. The general level of patient satisfaction was high. Zygomatic implants have a high success rate and constitute a suitable alternative to treat severe posterior maxillary atrophy.

The long-term use of zygomatic implants: a 10-year clinical and radiographic report

BACKGROUND

The zygoma implant has been an effective option in the short-term management of the atrophic edentulous maxilla.

PURPOSE

To report on long-term outcomes in the rehabilitation of the atrophic maxilla using zygomatic (ZI) and regular implants (RI).

MATERIAL AND METHODS

22 consecutive zygomatic patients in a maintenance program were included. Cumulative survival rate (CSR) of ZI, RI, prostheses, and complications were recorded during, at least, 10 years of loading. Implant mobility was tested using Periotest(®). Sinus health was radiographically and clinically assessed according to Lund-Mackay (L-M) score and Lanza and Kennedy survey, respectively. A satisfaction questionnaire and anatomical measurements were also performed.

RESULTS

Patients received 22 prostheses, anchored on 172 implants. Forty-one were ZI. Three RI failed (10 years CSR = 97.71%). Two ZI were partly removed due to perimplant infection (10 years CSR = 95.12%). All patients maintained functional prostheses. One patient fractured framework twice. Loosening or fracturing screws happened in 11 patients. Seven patients fractured occlusal material. Four ZI abutments in two patients were disconnected because of uncomfortable prostheses. Alveolar height at the ZI head level on the right and left sides was 2.64 mm and 2.25 mm, respectively. Mean distance of ZI head center to ridge center, on the right and left sides was 4.54 mm and 5.67 mm, respectively. Mean Periotest values (PTv) of ZI were -4.375 PTv and -4.941 PTv before prostheses placement and after 10 years, respectively. Six patients experienced sinusitis 14-127 months postoperatively. 54.55% of the L-M scores did not present opacification (L-M = 0) in any sinus. Osteomeatal obstruction happened in eight patients (two bilateral). Two (9.09%) were diagnosed with sinusitis. Eighty-four percent reported satisfaction levels above 80%. 31.81% reported maximum satisfaction score (100%).

CONCLUSIONS

The long-term rehabilitation of the severely atrophic maxillae using ZI is a predictable procedure.

Maxillary all-on-four therapy using angled implants: a 16-month clinical study of 1110 implants in 276 jaws

The maxilla is a challenging area for dental implant restoration. Encroachment of anatomic structures such as the sinus and nasal floor make vertical placement difficult. Implants placed at an angle may be used to avoid these anatomic structures or eliminate the need for a bone grafting procedure. The question occasionally arises about the possible detrimental effects of placing implants at an angle. This article reviews relevant literature, presents two case reports on maxillary angled implants and presents 3 years of data on 276 All-on-Four restorations.

Zygomatic implants: a critical review of the surgical techniques

PURPOSE

The purpose of the present study is to identify and describe the different surgical techniques for placement of zygomatic implants reported in the literature and discuss the differences between them.

METHODS

An electronic search was undertaken in July 2011. The titles and abstracts from these results (n = 130) were read for identifying studies, which reported different surgical techniques for placement of zygomatic implants, which resulted in 41 articles.

RESULTS

Five different surgical approaches were identified: (1) the classical approach, (2) the sinus slot technique, (3) the exteriorized approach, (4) the minimally invasive approach by the use of custom-made drill guides, and (5) the computer-aided surgical navigation system approach. When the maxilla is severely resorbed, the concavity formed by the ridge crest is small, and the original classical technique should be used. When maxillary resorption generates a large concavity, it would be better to exteriorize the zygomatic implant. The externalized technique has fewer surgical steps than the classical and sinus slot methods, is less invasive, and reduces surgical time. It is recommended that utilization of the sinus slot technique together with the CT-based drilling guide would enhance the final results. Although the technique that uses the computer-aided surgical navigation system approach may produce an improved precision in the clinical procedure, its use is expensive, prolongs the operation time, and is limited to centers that have the necessary equipment for the surgery.

CONCLUSIONS

Preference for one technique over the other should take into consideration the concavity formed by the ridge crest, maxillary sinus, and region of implant insertion in the zygomatic bone.