Indications for implant-supported rehabilitation of the posterior atrophic maxilla: A multidisciplinary consensus among experts in the field utilising the modified Delphi method.

PURPOSE: To establish consensus-driven guidelines that could support the clinical decision-making process for implant-supported rehabilitation of the posterior atrophic maxilla and ultimately improve long-term treatment outcomes and patient satisfaction. MATERIALS AND METHODS: A total of 33 participants were enrolled (18 active members of the Italian Academy of Osseointegration and 15 international experts). Based on the available evidence, the development group discussed and proposed an initial list of 20 statements, which were later evalu-ated by all participants. After the forms were completed, the responses were sent for blinded ana-lysis. In most cases, when a consensus was not reached, the statements were rephrased and sent to the participants for another round of evaluation. Three rounds were planned. RESULTS: After the first round of voting, participants came close to reaching a consensus on six statements, but no consensus was achieved for the other fourteen. Following this, nineteen statements were rephrased and sent to participants again for the second round of voting, after which a consensus was reached for six statements and almost reached for three statements, but no consensus was achieved for the other ten. All 13 statements upon which no consensus was reached were rephrased and included in the third round. After this round, a consensus was achieved for an additional nine statements and almost achieved for three statements, but no consensus was reached for the remaining statement. CONCLUSION: This Delphi consensus highlights the importance of accurate preoperative planning, taking into consideration the maxillomandibular relationship to meet the functional and aesthetic requirements of the final restoration. Emphasis is placed on the role played by the sinus bony walls and floor in providing essential elements for bone formation, and on evaluation of bucco-palatal sinus width for choosing between lateral and transcrestal sinus floor elevation. Tilted and trans-sinus implants are considered viable options, whereas caution is advised when placing pterygoid implants. Zygomatic implants are seen as a potential option in specific cases, such as for completely edentulous elderly or oncological patients, for whom conventional alternatives are unsuitable.

Mucosal cyst aspiration in conjunction with maxillary sinus elevation: A clinical cohort study.

INTRODUCTION: Patients with mucosal cysts in the maxillary sinus require special consideration in patients who require implant therapy for the restoration when undergoing implant therapy for the restoration of the posterior maxillary dentition. Treatment strategies for these clinical situations remain controversial in the literature. Thus, this study seeks to describe a safe and effective therapeutic strategy for sinus augmentation in patients with pre-existing maxillary antral cysts. METHODS: A total of 15 patients and 18 sinuses were consecutively enrolled in this cohort study and underwent maxillary antral cyst treatment by needle aspiration and simultaneous maxillary sinus augmentation (MSA). During surgical procedures, threeimplants (Zimmer Biomet, Indiana, USA) were positioned in 11 sinuses and two implants (Zimmer Biomet, Indiana, USA) were positioned in 5 sinuses. RESULTS: Overall implant success and survival rates were 100% and 97.8%, respectively at 1 year and 5-year follow-ups. Crestal bone resorption averaged 0.3 ± 0.2 mm 5-year post-loading, showing bone stability. Implant survival rate at 5-year follow-up expressed predictability of the technique comparable to historical data when MSA was performed alone. Crestal bone resorption averaged 0.3 ± 0.2 mm 5 years post-loading and shows bone stability utilizing mucosal cyst aspiration with concomitant MSA procedures. Quality of life evaluation at 1-week post-op showed similar results to published historical data. In 81% (13 sinuses), the CBCT examination at 5-year follow-up showed no cyst reformation, in 19% (3 sinuses) cyst reformation was visible, but smaller in size when compared to the pre-op CBCT evaluation, and all the patients were asymptomatic. CONCLUSIONS: Maxillary sinus mucosal cyst aspiration with concomitant MSA, may be a viable option to treat maxillary sinus cyst.

Remediation of a Failed Lateral Window Sinus Augmentation via a Palatal Approach: Rationale and Case Report.

Maxillary sinus elevation by the lateral window approach has been shown to be a highly predictable surgical procedure for increasing bone volume in the posterior maxilla. There are occasions, however, where this procedure may be difficult or impossible to perform in a highly predictable manner. There are many presurgical conditions and anatomical features that can make lateral window access difficult, leading to an increase in intraoperative complications and procedural failures. These complicating factors include complex internal sinus anatomy (multiple septa, anteroposterior septa), a narrow available window space, a thin or absent labial plate on adjacent teeth, and the presence of a root apex in the proposed window area, or it may be due to iatrogenically created defects, such as a previous failed sinus elevation, a healed oroantral fistula, or defects created by difficult extractions. While not frequently used or routinely reported in the literature, the palatal window approach may negate many of these obstacles. When it is reported, success rates are similar to those of lateral window procedures, and as an added advantage, postoperative morbidity is dramatically reduced, allowing the patient to wear a removable appliance immediately after surgery. There are, however, anatomical limitations that dictate when this procedure can be used. This case report is unique in that many of the lateral window complicating factors are present, and the palatal anatomy proved ideal for performing the technique.

Maxillary Sinus Elevation Difficulty Score with Lateral Wall Technique.

Maxillary sinus augmentation is a procedure commonly performed in patients in need of posterior maxillary implants with limited vertical ridge height and sinus pneumatization. However, minimal information has been presented to evaluate the complexity of the sinus elevation procedure via a lateral window approach based on patient examination, including extraoral findings, anatomical factors, and the possible influence from the surgeon's experience. Therefore, this article presents a new scheme of maxillary sinus floor elevation difficulty score based on comprehensive patient- and surgical-related factors. The proposed scoring tool aims to aid surgeons in performing a comprehensive presurgical evaluation prior to the lateral wall sinus augmentation surgery and also enhance communication between clinicians and patients regarding the complexity of the case.

Risk factors in lateral window sinus elevation surgery.

Maxillary sinus augmentation is the most predictable of the pre-prosthetic surgical procedures. There are, however, known and well-documented complications that can and do occur. The most common are the intraoperative complications of sinus membrane perforation and bleeding, and the postoperative complications of sinus graft infections, sinus infections, and sinusitis. The majority of these complications can be prevented, or their incidence greatly reduced, through a thorough understanding of maxillary sinus anatomy, the multifaceted etiologies of these conditions, and the steps that can be taken to avoid them. This volume of Periodontology 2000 will discuss both the preoperative and intraoperative procedures that will prevent these untoward outcomes and the necessary treatment modalities that will limit their adverse effects.

Maxillary Sinus Grafting With Biphasic Bone Ceramic or Autogenous Bone: Clinical, Histologic, and Histomorphometric Results From a Randomized Controlled Clinical Trial.

PURPOSE: The present, randomized, controlled clinical trial compared the histologic and histomorphometric results from maxillary sinus augmentation with either biphasic calcium phosphate (BCP) (60% hydroxyapatite and 40% ß-tricalcium phosphate) or autogenous bone (AB) as bone-grafting materials. MATERIAL AND METHODS: Ten patients received bilateral sinus elevation surgery with intraoral AB chips (control group) on one side and BCP (test group) on the contralateral side. After a healing period of 6 to 8 months, implant sites were created and trephine cores were harvested for histological and histomorphometric analysis of the grafted areas. RESULTS: The histological examination of biopsies showed BCP particles interconnected by bridges of a vital newly formed bone. Histomorphometry demonstrated that the amount of newly formed bone in the control group (36.8%) was significantly greater than that in the BCP (28.2%) group (P = 0.0032). BCP and AB cores revealed an average of residual graft particles of 32.9% and 4.8%, respectively. The average percentage of soft tissue components was 38.9% in the BCP cores and 58.4% in the AB cores. CONCLUSIONS: Based on our findings, the amount of vital bone formation was significantly higher for AB than that for BCP. However, BCP seemed to be a biocompatible and osteoconductive material that can be used with success as a bone substitute in maxillary sinus procedures.

A comprehensive clinical review of maxillary sinus floor elevation: anatomy, techniques, biomaterials and complications.

Several systematic reviews have shown that maxillary sinus augmentation is a predictable and effective procedure for augmentation of an atrophic posterior maxilla. However, we know of no reviews that have covered all the clinical aspects. We searched the PubMed, EMBASE, Cinhal, and Cochrane databases up to January 2015 to select relevant studies that cover the different objectives of this review, including the anatomy of the maxillary sinus, surgical techniques, biomaterials used in the sinus augmentation, and potential complications.

Effect of xenograft (ABBM) particle size on vital bone formation following maxillary sinus augmentation: a multicenter, randomized, controlled, clinical histomorphometric trial.

The purpose of this study was a histomorphometric comparison of vital bone formation following maxillary sinus augmentation with two different particle sizes of anorganic bovine bone matrix (ABBM). Bilateral sinus floor augmentations were performed in 13 patients. Trephine bone cores were taken from the lateral window areas of 11 patients 6 to 8 months after augmentation for histologic and histomorphometric analysis. Bone samples from both the large and small particle size groups showed evidence of vital bone formation similar to that seen in previous studies, confirming the osteoconductivity of ABBM. Significant bone bridging was seen creating new trabeculae composed of the newly formed bone and residual ABBM particles. Histologic evaluation revealed the newly formed bone to be mostly woven bone with some remodeling to lamellar bone. Osteocytes were seen within the newly formed bone as well as osteoblast seams with recently formed osteoid. Isolated osteoclasts were observed on the ABBM surfaces. Vital bone formation (primary outcome measure) was more extensive in the large particle grafts compared with the small particle grafts (26.77% ± 9.63% vs 18.77% ± 4.74%, respectively). The histologic results reaffirm the osteoconductive ability of ABBM when used as the sole grafting material in maxillary sinus augmentation. The histomorphometric results at 6 to 8 months revealed a statistically significant increase (P = .02) in vital bone formation when the larger particle size was used. Additional studies should be performed to confirm these results.

Maxillary sinus elevation by lateral window approach: evolution of technology and technique.

CONTEXT: The maxillary sinus elevation procedure has become an important pre-prosthetic surgical procedure for the creation of bone volume in the edentulous posterior maxilla for the placement of dental implants. Research and clinical experience over the past 30 years has increased the predictability of this procedure as well as reduced patient morbidity. EVIDENCE ACQUISITION: Data on grafting materials and implant survival rates comes from 10 published evidence-based reviews that include all relevant published data from 1980 to 2012. Supporting clinical material comes from the experience of the authors. EVIDENCE SYNTHESIS: The evidence-based reviews report and compare the implant survival rates utilizing various grafting materials, implant surfaces, and the use or non-use of barrier membranes over the lateral window. Clinical studies report on complication rates utilizing piezoelectric surgery and compare them to complication rates with rotary instrumentation. CONCLUSIONS: The conclusions of all the evidence-based reviews indicate that the utilization of bone replacement grafts, rough-surfaced implants, and barrier membranes result in the most positive outcomes when considering implant survival. Further, the utilization of piezoelectric surgery, rather than rotary diamond burs, for lateral window preparation and membrane separation leads to a dramatic reduction in the occurrence of the intraoperative complications of bleeding and membrane perforation.

Histologic and histomorphometric evaluation of an allograft stem cell-based matrix sinus augmentation procedure.

PURPOSE: Long-term success of dental implants has been demonstrated when placed simultaneously with or after a sinus augmentation procedure. However, optimal bone formation can be from 6 to 9 months or longer with grafting materials other than autogenous bone. For this reason, there is interest in any surgical technique that does not require autogenous bone harvesting, yet results in sufficient bone formation within a relatively short time frame. MATERIALS AND METHODS: This study evaluated and compared bone formation following sinus-augmentation procedures using either an allograft cellular bone matrix (ACBM), containing native mesenchymal stem cells and osteoprogenitors, or conventional allograft (CA). RESULTS: Histomorphometric analysis of the ACBM grafts revealed average vital bone content of 32.5% ± 6.8% to residual graft content of 4.9% ± 2.4% for the 21 sinuses in the study, at an average healing period of 3.7 ± 0.6 months. Results for the CA, in the same time frame, were average vital bone content of 18.3% ± 10.6% to residual graft content of 25.8% ± 13.4%. A comparison of ACBM and CA grafts, for both vital and residual bone contents, showed P values of .003 and .002, respectively, indicating a statistically significant difference between the groups. CONCLUSION: The high percentage of vital bone content, after a relatively short healing phase, may encourage a more rapid initiation of implant placement or restoration when a cellular grafting approach is considered.

Histomorphometric comparison of a biphasic bone ceramic to anorganic bovine bone for sinus augmentation: 6- to 8-month postsurgical assessment of vital bone formation. A pilot study.

This blinded, randomized, controlled pilot investigation is the first to histomorphometrically compare vital bone formation following bilateral sinus grafting with a biphasic calcium phosphate (BCP) (Straumann Bone Ceramic) to an anorganic bovine bone matrix (ABBM) (Bio-Oss) 6 to 8 months following graft placement. Twelve patients were selected. Following elevation of the lateral sinus walls, one material was placed in the right sinus and the other material was placed in the left sinus, as determined by randomization. Six to 8 months after grafting (with the same time frame used for each patient), a trephine core was taken from the grafted area and sent for histomorphometric analysis. Cores were obtained from 21 healed sinuses in 12 patients. Nine patients provided bilateral cores. Histomorphometric analysis of 10 BCP cores and 11 ABBM cores revealed an average vital bone content of 28.35% and 22.27%, respectively. The average percentage of residual graft particles was 28.4% in the BCP cores and 26.0% in the ABBM cores. The difference in vital bone formation was not significantly different (n = 9 patients, paired t test) between bilateral sinuses treated with the BCP and those treated with the ABBM. Histologically, both materials appeared to be osteoconductive and support new bone formation. Future studies are needed to confirm the ability of this regenerated bone to support dental implant maintenance over time.

Maxillary sinus augmentation: evidence-based decision making with a biological surgical approach.

Sinus elevation surgery has been used by the dental profession to increase bone quantity in the posterior maxilla for the placement of root-form implants. The original treatment protocol was developed using existing bone-healing theories that relied on expert opinion. In 2003 and 2004, 2 evidence-based literature reviews were published, expanding significantly on the previous review of 1996. The new reviews were based on the best studies available and were designed to present information that would help clinicians achieve more favorable outcomes. This article discusses this information and answers further questions relating to the sinus elevation procedure.

Comparison of mineralized cancellous bone allograft (Puros) and anorganic bovine bone matrix (Bio-Oss) for sinus augmentation: histomorphometry at 26 to 32 weeks after grafting.

The present blinded, randomized, controlled investigation histomorphometrically evaluated the vital bone formed following bilateral grafting with two different materials--Puros, a mineralized cancellous bone allograft (MCBA), and Bio-Oss, an anorganic bovine bone matrix (ABBM)--at 26 to 32 weeks following graft placement. Thirteen patients were selected who required bilateral sinus augmentation. Following elevation of the lateral sinus walls, one material was placed in the right sinus and the other in the left sinus, as determined by randomized choice. Twenty-six to 32 weeks after grafting (the same time frame was used for each individual patient), a trephine core was taken from the previously elevated lateral wall area and sent for histomorphometric analysis. Cores were obtained from 22 healed sinus augmentations in 11 patients. Eight patients provided bilateral cores, two patients had intact MCBA cores but inadequate ABBM cores, and another patient had an intact ABBM core but an inadequate MCBA core. Histomorphometric analysis of 10 MCBA cores and 9 ABBM cores revealed average vital bone content of 28.25% and 12.44%, respectively. The average percentage of residual nonvital bone was 7.65% in the MCBA cores and 33.0% in the ABBM cores. Significantly more bone was formed in the MCBA sites (n = 8 patients, paired t test). Histologically, both MCBA and ABBM particles were surrounded by new bone, osteoid, and osteoblasts. A higher average percentage of new vital bone was seen around the MCBA particles than around the ABBM particles.

Effect of maxillary sinus augmentation on the survival of endosseous dental implants. A systematic review.

BACKGROUND: Grafting the floor of the maxillary sinus has become the most common surgical intervention for increasing alveolar bone height prior to the placement of endosseous dental implants in the posterior maxilla. Outcomes of this procedure may be affected by specific surgical techniques, simultaneous versus delayed implant placement, use of barrier membranes over the lateral window, selection of graft material, and the surface characteristics and the length and width of the implants. RATIONALE: The primary objective of this systematic review was to determine the efficacy of the sinus augmentation procedure and compare the results achieved with various surgical techniques, grafting materials, and implants. FOCUSED QUESTION: In patients requiring dental implant placement, what is the effect on implant survival of maxillary sinus augmentation versus implant placement in the non-grafted posterior maxilla? SEARCH PROTOCOL: MEDLINE, the Cochrane Oral Health Group Specialized Trials Register, and the Database of Abstracts and Reviews of Effectiveness were searched for articles published through April 2003. Hand searches were performed on Clinical Oral Implants Research, International Journal of Oral and Maxillofacial Implants, and the International Journal of Periodontics & Restorative Dentistry and the bibliographies of all relevant papers and review articles. In addition, researchers, journal editors, and industry sources were contacted to see if pertinent unpublished data that had been accepted for publication were available. INCLUSION CRITERIA: Human studies with a minimum of 20 interventions, a minimum follow-up period of 1-year loading, an outcome measurement of implant survival, and published in English, regardless of the evidence level, were considered. EXCLUSION CRITERIA: Studies involving multiple simultaneous interventions (e.g., simultaneous ridge augmentation) and studies with missing data that could not be supplied by the study authors were excluded. DATA COLLECTION AND ANALYSIS: Where adequate data were available, subgroups of dissimilar interventions (e.g., surgical techniques, graft materials, implant surfaces, membranes) were isolated and subjected to meta-regression, a form of meta-analysis. MAIN RESULTS: 1. Forty-three studies, 3 randomized controlled clinical trials (RCTs), 5 controlled trials (CTs), 12 case series (CS), and 23 retrospective analyses (RA) were identified. Thirty-four were lateral window interventions, 5 were osteotome interventions, 2 were localized management of the sinus floor, and 2 involved the crestal core technique. 2. Meta-regression was performed to determine the effect of the variables of block versus particulate grafting techniques, implant surface, graft material, and the use of a membrane over the lateral window. 3. The survival rate of implants placed in sinuses augmented with the lateral window technique varied between 61.7% and 100%, with an average survival rate of 91.8%. For lateral window technique: 4. Implant survival rates reported in this systematic review compare favorably to reported survival rates for implants placed in the non-grafted posterior maxilla. 5. Rough-surfaced implants have a higher survival rate than machine-surfaced implants when placed in grafted sinuses. 6. Implants placed in sinuses augmented with particulate grafts show a higher survival rate than those placed in sinuses augmented with block grafts. 7. Implant survival rates were higher when a membrane was placed over the lateral window. 8. The utilization of grafts consisting of 100% autogenous bone or the inclusion of autogenous bone as a component of a composite graft did not affect implant survival. 9. There was no statistical difference between the covariates of simultaneous versus delayed implant placement, types of rough-surfaced implants, length of follow-up, year of publication, and the evidence level of the study. REVIEWERS' CONCLUSIONS: Insufficient data were present to statistically evaluate the effects of smoking, residual crestal bone height, screw versus press-fit implant design, or the effect of implant surface micromorphology other than machined versus rough surfaces. There are insufficient data to recommend the use of platelet-rich plasma in sinus graft surgery.