ORIS Criteria of Success for the Zygoma-Related Rehabilitation: The (Revisited) Zygoma Success Code
Abstract and Figures
Zygomatic-related implant rehabilitation differs from traditional implant treatment in biomechanics, clinical procedures, outcomes, and eventual complications such as soft tissue incompetence or recession that may lead to recurrent sinus/soft tissue complications. The extreme maxillary atrophy that indicates the use of zygomatic implants prevents use of conventional criteria to describe implant success/failure. Currently, results and complications of zygomatic implants reported in the literature are inconsistent and lack a standardized systematic review. Moreover, protocols for the rehabilitation of the atrophic maxilla using zygomatic implants have been in continuous evolution. The current zygomatic approach is relatively new, especially if the head of the zygomatic implant is located in an extramaxillary area with interrupted alveolar bone around its perimeter. Specific criteria to describe success/survival of zygomatic implants are necessary, both to write and to read scientific literature related to zygomatic implant-based oral rehabilitations. The aim of this article was to review the criteria of success used for traditional and zygomatic implants and to propose a revisited Zygomatic Success Code describing specific criteria to score the outcome of a rehabilitation anchored on zygomatic implants. The ORIS acronym is used to name four specific criteria to systematically describe the outcome of zygomatic implant rehabilitation: offset measurement as evaluation of prosthetic positioning; rhino-sinus status report based on a comparison of presurgical and postsurgical cone beam computed tomography in addition to a clinical questionnaire; infection permanence as evaluation of soft tissue status; and stability report, accepting as success some mobility until dis-osseointegration signs appear. Based on these criteria, the assessment of five possible conditions when evaluating zygomatic implants is possible.
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... The outcome of the combination of the ZAGA protocols together with the new Straumann ® Zygomatic Implant System was evaluated using the ORIS criteria for a systematic report of a zygomatic implant-related rehabilitation [28,29]. ...
... Based on these criteria, one of five possible conditions is assigned to each implant. Following the ORIS criteria [28], two independent researchers (B Al-N and WP) from separate centers, blinded to the study, analyzed the radiological outcomes by comparing pre-operative and postoperative CBCT images. The analysis was simple and consisted of comparing the screenshot with the virtual planning of the implant with screenshots showing the actual implant already placed in the planned site. ...
... The unique characteristics of zygomatic implants and their distinct anatomical context necessitate specialized evaluation criteria separate from those used for conventional implants. Specific criteria called ORIS have been introduced [28] to assess the outcomes of zygomatic implant-supported rehabilitations to address this need. These criteria enable clinicians to conduct standardized follow-ups, employing strict benchmarks tailored to the intricacies of zygomatic implant treatment. ...
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.
... Some studies suggest an association between thinner mucosal phenotypes and increased peri-implant bone loss [49] and recession of the peri-implant mucosal margin [50]. However, other studies registered no association between the exposure of the zygomatic implant body and implant failure [19,21,51,52]. Nevertheless, as soft tissue dehiscence exposes the zygomatic implant body, this makes it more difficult for the patient to perform good self-care and increases the risk of additional complications such as sinus communication, mucositis, or cellulitis [19,51,52]. ...
... However, other studies registered no association between the exposure of the zygomatic implant body and implant failure [19,21,51,52]. Nevertheless, as soft tissue dehiscence exposes the zygomatic implant body, this makes it more difficult for the patient to perform good self-care and increases the risk of additional complications such as sinus communication, mucositis, or cellulitis [19,51,52]. Protocols to prevent these potential complications could include the displacement of the buccal fat pad [53,54] over the zygomatic implant body, or the ZAGA Scar Graft [55]. ...
Background/Objectives: There is a need for alternative approaches to full-arch rehabilitation of atrophic maxillae. The aim of this short case series was to describe the technique and assess the short term-outcomes of atrophic maxillae rehabilitation using transnasal implants in conjunction with zygomatic implants. Methods: Three female patients (average age: 62 years) presenting comorbidities and atrophic maxillae preventing the insertion of standard maxillary anchored implants received a full-arch fixed prosthesis supported by transnasal implants together with zygomatic implants, using the ad modum all-on-4 concept. Patients were followed during the functional osseointegration period. Primary outcome measures were prosthetic and implant survival based on function. Secondary outcome measures were complication parameters (biological and mechanical), plaque and bleeding levels, and probing pocket depths > 4 mm. Results: No implant failures were registered, and all prostheses remained in function. The only complication was a fracture of a provisional crown that was resolved. Plaque and bleeding scores were mild during the follow-up period. Conclusions: The present manuscript describes the use of extra-long transnasal implants in combination with zygomatic implants in immediate function for full-arch fixed prosthetic rehabilitation of atrophic maxillae, with the objective of promoting more research into this relatively recent technique. More studies are needed to validate the technique.
... 34 On the other hand, more specific criteria had to be applied to the zygomatic implants. The criteria depended on the peculiar shape of the implant and on the anatomical and morphological features of the areas in which the zygomatic implants had to be placed, so clinicians had been forced to introduce the criteria of Offset, Rhinosinusitis, Infection, and Stability classification.Unambiguous success criteria for assessing the prosthetic status and evaluating the state of health of the maxillary sinus mucosa, and also the stability of the anchored zygomatic implants, had been introduced with positive results.14 ...
Purpose:
The study aimed to compare the short-term outcomes (3.7±0.4yrs) of full-arch immediately loaded fixed maxillary prostheses supported by conventional and unilateral single zygomatic implants versus those supported by conventional and bilateral single zygomatic implants.
Methods:
A retrospective analysis was conducted on patients suffering severe bone loss in the posterior area of the maxilla. The success of zygomatic implants was defined following Offset-Rhinosinusitis-Infection-Stability (ORIS) criteria. The criteria used to define success of standard dental implants were absence of mobility, pain, discomfort/neurologic disorder, and of persistent or chronic infection. The level of significance was 0.01.
Results:
Thirty-eight patients received 2-5 standard implants plus two zygomatic implants (bilateral), whereas 10 patients had 3-5 standard implants plus a single zygomatic implant (unilateral). The cumulative success rate for standard implants was 99% and 97.3%, respectively, in the bilateral and unilateral groups. Four patients showed symptoms of acute rhinosinusitis (R-criterion): 1 in the unilateral and 3 in the bilateral group. Following the O-criterion, just 2 dental implants in the bilateral group showed a success grade 1. One zygomatic implant, belonging to the group bilateral, developed peri-implant mucositis with a success grade 3 (I-criterion). All zygomatic implants were checked individually and did not show either any signs of mobility or rotation after applying forces to the implant (S-criterion). The ORIS criteria divided the implants into three groups according to the success grades I,II,III: 32,36,8 for the bilateral, and 6,1,3 for the unilateral group, with no significant difference between the two groups. No zygomatic implant failure occurred so that the same zygomatic implant success rate (100%) was recorded for both groups. A prosthetic failure was registered in the unilateral group. The overall prosthesis success rates were 89.5% and 70%, respectively, in the bilateral and unilateral groups.
Conclusions:
A high degree of success was achieved for both groups treated with zygomatic implants, although in group unilateral there was one failure of a standard dental implant placed in the posterior area. This suggested that the use of zygomatic implants could provide adequate support to the fixed full-arch prostheses even in the configuration with a single unilateral zygomatic implant.
... Thus, Aparicio et al. outlined four distinct criteria to be considered: offset of the definitive prostheses, rhinosinus condition, soft tissue infection, and stability. [9] Evaluating these criteria allows a practitioner to categorize a patient into one of the following five conditions: ...
Background
One of the most critical complications that can occur after placing zygomatic implants is the accidental penetration of the patient's eye socket by a drill or implant. This article aims to find some relationships between the anatomical features of the lower orbital wall, different configuration of zygomatic implants, and other factors when planning the placement of zygomatic implants.
Methods
A total of 81 patients underwent zygomatic implant procedures, receiving different combinations of implants. These included four zygomatic implants along with one or two conventional implants (Group I), four zygomatic implants alone (Group II), two zygomatic implants paired with four conventional implants (Group III), or three zygomatic implants alongside one or two conventional implants (Group IV). The aim of the study was to describe the complications and clinical outcomes of treatment in 81 patients who received zygomatic implants.
Results
The following parameters were statistically significant between all four groups of patients: height and distance of two zygomatic implants in the zygomatic bone; surgery type and duration; the distance between zygomatic implants in the zygomatic bone; and zygomatic orbital floor (ZOF) classification at the left side showed significant differences; intramaxillary insertion of zygomatic implants reduced the rupture of Schneiderian’s membrane; the average of zygomatic implants’ length in all groups was 42.8 mm.
Conclusions
Not damaging the ZOF is profoundly important for preventing orbital damage during osteotomy for zygomatic implants and should be measured before every surgery.
... Aparicio updated the ORIS criteria of success in 2020 by revising the zygoma success code. 15 The evaluation of zygomatic implants can be divided into five categories based on Aparicios criteria: Success Condition 1: At this point, the zygomatic implant performs exceptionally well and satisfies all the requirements for success. It is the ideal stage. ...
Zygoma implants, sometimes called zygomatic implants, are different from conventional dental implants in that they are affixed in the zygomatic bone, not the maxilla. They can be used in situations when there is not enough maxillary bone, either in terms of quantity or consistency, to support a dental implant. Insufficient maxillary bone volume may result from a combination of maxillary sinus pneumatization and bone resorption. To guarantee proper implant survival, the normal implant placement in the posterior maxilla requires a bone height of about 10 mm. Increased bone volume can be achieved by sinus elevation and bone grafting techniques in cases when there is insufficient bone available. The drawbacks of bone grafting procedures in the jaws include the need for prolonged care, restrictions on denture wear, morbidity at the donor surgical site, and graft rejection. Keywords: Zygomatic implants, Prosthodontic Rehabilitation, Prosthetically driven approach
... This detailed planning is instrumental in preventing both intraoperative and postoperative complications, ultimately ensuring the success of the prosthodontic rehabilitation. By addressing these considerations, practitioners can enhance the predictability and safety of the Quad Zygoma surgery, contributing to favourable outcomes for patients with severely atrophic maxilla [3]. ...
Purpose
Quad zygoma surgery is challenging procedure that requires an accurate prosthetic and implant planning. The objective of our study was to evaluate zygomatic implants placed according to quad zygoma protocol in the severely absorbed maxilla on cone beam computed tomography (CBCT) scans using an virtual implant placement program and to compare the variables according to gender.
Methods
56 zygomatic bones from 28 patients were examined using CBCT scans. A total of 112 zygomatic implants were evaluated to zygomatic bone-implant contact (BIC) lenght, the relationship zygomatic implants between the maxillary sinus and zygomaticofacial foramen were compared and analyzed by gender on the virtually placed anterior and posterior implants on the three-dimensional reconstruction images.
Results
The average zygomatic BICs length in males was found to be 11.77 ± 3.47 mm, in females 11.23 ± 2.61 mm. Among the anterior and posterior exit profile according to zygoma anatomy-guided approach (ZAGA) classification, respectively, 1.7% and 7.2% were classified as ZAGA 0, 7.2% and 7.2% as ZAGA 1, 16.1% and 21.4% as ZAGA 2, 55.3% and 14.2% as ZAGA 3, 19.7% and 50.0% as ZAGA 4. No statistically significance found between gender-related parameters that were investigated. However, it was found that the contact to zygomaticofacial foramen was significantly higher in implants with an anterior exit profile compared to implants placed posteriorly (p < 0.05).
Conclusion
Examining the anatomy of the region with three-dimensional imaging techniques before quad zygoma surgery and conducting surgical rehearsals with programs that allow virtual surgery are crucial to prevent potential complications.
... For this purpose, the main estimated values of X-ray bone tissue density were implemented using the Hounsfield scale (HU) [11]: a healthy bone (D1) at ≥850 HU; a pastous bone (D2) at 350-850 HU; and a bone affected by local osteoporosis (D3) at ≤350 HU. However, in spite of manufacturers' recommendations for the use of a specific type of zygomatic implants depending on the presence and condition of bone tissue, the selection of their number and configuration is made intuitively in most cases, taking into account the experience of maxillofacial surgeons [12,13]. When installing zygomatic implants, an important aspect is to predict their mechanical behavior in addition to some other biomedical issues (primarily, osseointegration). ...
The research addresses evaluation of stress-strain state (SSS) in the “zygomatic bones–implants–denture base” system by varying the type and number of the zygomatic implants, as well as applying loads. The load magnitude was varied over a wide range, characteristic of the mastication process. Changing the adhesion conditions at the “zygomatic implant–bone tissue” interface varied both the level of maximum stress and the location of the critical stress concentrator. The local violation of the integrity of bone tissue in the skull was one of the key reasons for the redistribution of stresses in the “zigomatic implantdenture base” system. Such a phenomenon should be primarily taken into account when choosing the standard sizes of installed zygomatic implants in order to reduce the compliance of weakened areas of the skull (as the basis of the load-bearing structure). Based on the results of the FEM-based computer simulation, the algorithm was proposed for planning prosthetic treatment, which involves the iterative method for selecting both size and location of installing zygomatic implants depending on the results of the SSS calculation and the onset of a critical condition (primarily in bone tissue at the contact area with zygomatic implants).
Zygoma implants are an alternative for rehabilitating severe maxillary atrophy. Since 2004, when Prof. Branemark first reported the long-term findings on zygomatic implants using the original intra-sinus approach, various surgical techniques have been introduced. In 2006, an anatomy-guided approach was developed, applying different implant trajectories based on alveolar atrophy levels and sinus concavity. The purpose of this review is to clarify the existing techniques and long-term outcomes of ZI rehabilitation over the past 20 years. Additionally, it aims to enhance the quality of current practices and identify gaps in the understanding of ZI treatment for future studies.
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.
PurposeThe 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 (R) (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. ResultsNo 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 (5.122.38mm vs 2.92 +/- 2.30mm). 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.
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.
Background: The surgical protocol for zygomatic fixtures prescribes an intrasinus approach ideally maintaining the sinus membrane intact and the implant body inside the sinus while gaining access to the zygomatic bone. In the presence of a pronounced buccal concavity, the implant head has to be placed far from the alveolar crest in a palatal direction, which results in a bulky bridge construction.
Purpose: The aim of this study was to report on the preliminary experiences with zygomatic implants placed with an extrasinus approach in order to have the implant head emerging at or near the top of the alveolar crest.
Materials and Methods: Twenty consecutive patients with pronounced buccal concavities in the edentulous posterior maxilla were treated with 104 regular and 36 zygomatic implants as support of fixed dental bridges. Sixteen patients were treated bilaterally and four patients were treated unilaterally. The zygomatic implants were inserted by using an extrasinus surgical approach with the implant body passing from the alveolar crest through the buccal concavity into the zygomatic bone. This enabled placement of the implant head at or close to the alveolar crest. The patients were followed from 36 to 48 months after occlusal loading with a mean follow-up of 41 months. The relation of the zygomatic implants to the crest was measured and compared with a control group of 20 patients treated with conventional placement of zygomatic implants.
Results: No implants were lost during the study period. No pain, discomfort, or complications related to the extrasinus path of the zygomatic implants were recorded after the initial healing period and up to the 36th-month checkup. The zygomatic implants emerged, on average, 3.8 mm (SD 2.6) palatal to the top of the crest compared with 11.2 mm (SD 5.3) to the conventional technique.
Conclusion: The present 3-year clinical study shows that an extrasinus approach can be utilized when placing zygomatic implants in patients with pronounced buccal concavities in the posterior maxilla. Moreover, the technique results in an emergence of the zygomatic fixture close to the top of the crest, which is beneficial from a cleaning and patient-comfort point of view.
The aim of the present systematic review was to evaluate reported survival rate and marginal bone (MBL) loss of implants with different surface roughness and followed up for 10 years or longer. For the majority of the 62 included clinical studies, no direct comparison between different surfaces was made, thus our report is mainly based on reported survival rates and marginal bone loss for individual implant brands with known surface roughness. The survival rate was 82.9 to 100% for all implants after 10 or more years in function and the marginal bone loss was, on average, less than 2.0 mm for all implant surfaces included, i.e. turned, titanium plasma sprayed (TPS), blasted, anodised, blasted and acid-etched but the turned surface in general demonstrated the smallest MBL. However, the survival rates were in general higher for moderately rough surfaces. The roughest TPS surface demonstrated the highest probability for failure, while the anodised showed the lowest probability. In conclusion, the present systematic review demonstrates that it is possible to achieve very good long-term results with all types of included surfaces.
The prevalence, causes and consequences of crestal bone loss at dental implants are a matter of debate. In recent years, a high prevalence of peri-implant soft-tissue inflammation, associated with peri-implant bone loss, has been reported and the need for treatments similar to those offered for natural teeth affected by periodontitis has been proposed. This suggestion is based on the assumption that periodontal indices, such as probing pocket depth and bleeding on probing, are reliable indicators of the peri-implant tissue conditions and good predictors of future bone loss. However, based on a critical review of the literature in the present paper, it is concluded that periodontal indices are not reliable either for identifying peri-implant disease or for predicting future risk for peri-implant crestal bone loss and implant failure. The long-term experiences with dental implants, presented in the literature, indicate that the presence of bleeding on probing, probing pocket depths much larger than 4 mm and some bone loss seem to reflect, in most instances, normal conditions of well-functioning dental implants, bearing in mind that healing of dental implants is the result of a foreign body reaction with the formation of scar tissue. Therefore, the use of probing pocket depth and bleeding on probing assessments may lead to over-diagnosis and possibly to over-treatment of assumed biofilm-mediated peri-implantitis lesions. It is the opinion of the authors of this review that a treatment should only be initiated when a clinical problem is present based on patient's symptoms (discomfort, pain), the presence of swelling, redness and pus, and significant crestal bone loss over time (as verified with radiographs). The treatment should aim at resolving the infection, which could include removal of the implant. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
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.
This study reports on the histologic characteristics of the early phases of implant osseointegration, focusing on osteopontin concentrations in the coronal area of implants placed with marginal defects and in control sites without defect preparation. In the mandibular right area of 12 dogs, two recipient sites were prepared and the margins were widened to obtain a gap of 0.5 mm at one site (small defect) and 1.25 mm at another site (large defect). Implants were placed and allowed a fully submerged healing. The procedure was subsequently performed in the left side in such a way as to obtain healing times of 5, 10, 20, and 30 days. Paraffin sections were stained with osteopontin antibodies and analyzed. At control implants, scarcely organized collagen fibers were observed in the space between the pristine bone and implant and were quickly replaced by mineralized tissue. In the small and large defects, the collagen fibers were organized in a layer that ran parallel to the implant at day 10 and became denser and thicker with time. Osteopontin was evenly distributed in the peri-implant tissue at control implants, while it was mainly located in the collagen bundle section around the implants placed in the defects.
Purpose:
The zygomatic implant is mainly indicated for the rehabilitation of extremely atrophied maxillae when bone augmentation should be avoided. One drawback of zygomatic implants, which typically pass through the sinus, is initial or late bone resorption around the implant neck, which can result in oroantral communications followed by possible infection of the sinus. To decrease the risk of sinus infection, a modified technique was developed to preserve the integrity of the sinus membrane and to regenerate bone around zygomatic implants using an extended sinus grafting approach.
Materials and methods:
Patients with extremely atrophied maxillae were provided with one to four zygomatic implants in conjunction with sinus grafting, plus conventional auxiliary implants, for immediate support of a provisional full-arch maxillary prosthesis. Definitive prostheses were delivered at 6 months after implant placement. All patients underwent clinical and radiographic examinations at 6 months.
Results:
Twenty-two zygomatic and 23 conventional auxiliary implants were placed in 10 patients. The overall 6-month implant survival rate was 90.9% for zygomatic implants and 100% for auxiliary implants placed in the anterior area. Only two minor technical complications were seen, and clinical indicators (including probing pocket depth, keratinized tissue, and plaque and bleeding indices) were good in all patients. A substantial gain of radiographic bone around the zygomatic implants was observed.
Conclusion:
The proposed technique led to successful prosthetic function for all patients. With the described technique, exposed implant threads within the maxillary antrum are eliminated and the potential for biologic complications is minimized.
