Atrophic Posterior Maxilla Research Articles

Short implant versus conventional implant in the posterior atrophic maxilla: A systematic review and meta-analysis

Objective: A comparative study undertaken to measure the the marginal bone loss (MBL), implant survival rate, and prosthetic and biological complications among short implants (8 mm or shorter) and conventional implants (longer than 8 mm) in the posterior atrophic maxilla. Materials and Methods: A search in three databases PubMed (Medline), Scopus, and Cochrane was conducted. The present systematic review was registered with identification number CRD42020212805 at the International Prospective Register of Systematic Reviews. Data extraction included the publication year, patients’ number and number of implants, implant length and width, MBL, implant survival rate, and biological and mechanical complications. The Cochrane Risk of Bias 1.0 tool was used to assess the risk of bias. A meta-analysis was performed to evaluate the outcome variables. Comparisons for dichotomous variables, such as prosthetic and biological complications and implant survival rate, were done by applying the Mantel–Haenszel method. In contrast, a comparison was made by applying the inverse variance method for continuous variables like MBL. Results: Initially, 618 reports were recognized from electronic database searches. Five randomized controlled trials (RCTs) were included in the meta-analyses regarding the MBL, implant survival rate, and prosthetic complications, while three were included for biological complications. In 5 years of follow-up, no evidence of difference could be found between conventional and short implants for survival rate (risk ratio [RR]: 3.54; 95% confidence interval [CI]: 0.99–12.67; P = 0.05; I 2 = 0%). We do not find any evidence of difference for MBL between short implants and conventional implants (mean difference: −0.29; 95% CI: −0.49 to −0.08; P = 0.02; I 2 = 65%). Furthermore, no evidence of a difference exists between short and conventional implants for prosthetic complications (RR: 1.56; 95% CI: 0.68–3.55; P = 0.29; I 2 = 0%). The biological complications were seen less with short implants (RR: 0.47; 95% CI: 0.24–0.93; P = 0.03; I 2 = 0%). Conclusion: The results suggest no significant difference among conventional and short implants regarding survival rate in the posterior atrophic maxilla. The results of this systematic review and meta-analysis suggest that, for a 5-year period of follow-up, short implants are related to rarer biological complications and comparable MBL compared to conventional implants. Despite these promising findings, long-term studies with consistent study designs and clinical protocols are required to appraise the performance and durability of short implants.

Trans-crestal dental implants in the rehabilitation of a severely atrophic maxilla: A retrospective case series.

To evaluate the mid-term clinical and radiographic results of immediate fixed full-arch prosthesis supported by two anterior axial and two posterior trans-crestally placed tilted implants in patients with severely atrophic posterior maxilla. Patients with posterior maxillary ridge less than 4 mm high and 3 mm wide were rehabilitated with an immediate fixed provisional prosthesis supported by two anterior axially placed and two trans-crestal posterior tilted implants within 3 h after implant surgery. The final prosthesis, consisting of a CAD-CAM titanium framework and composite teeth was delivered 6 months later. Patients were scheduled for follow-up visits every 6 months to assess clinical and radiological parameters. Patients' satisfaction was assessed by a questionnaire up to 5 years. From April 2008 to May 2017, 56 implants (28 axial and 28 tilted) were inserted in 14 subjects (eight female and six male). The average bone loss for the anterior axial implants was 0.99 ± 0.19 mm at 1 year (n = 28 implants), 1.37 ± 0.31 mm at 5 years (n = 28), and 2.05 ± 0.32 mm at 10 years (n = 14). Only for three implants in two subjects the marginal bone loss was higher than 2 mm after 60 months. No implant was lost, and no prosthetic failure occurred after a mean follow-up of 125 months (range 79-186 months), leading to 100% implant and prosthesis survival rates. The upper 95% confidence limit of the failure rate was 23% and 6% at patient and implant level, respectively. High level of satisfaction was reported at 5-year follow-up. Wider sample sizes will be required to determine whether the presented technique is a reliable treatment option for the immediate rehabilitation of the atrophic maxilla.

A new classification for pterygomaxillary implants and its related surgical implications: a retrospective cohort study

BackgroundTo provide a novel classification for all implants in the maxillary retromolar region to simplify surgical design, reduce surgical risks, and guide clinicians in clinical decision-making.MethodsA total of 180 patients with bilateral partial or completely edentulous atrophic posterior maxillae who had received or were scheduled to receive pterygomaxillary implants were included in this study. Cone-beam computed tomography was performed, and the sagittal and coronal images were acquired at 110 kV and 10 mA. The exposure volume was 120 mm in diameter and 80 mm in height. The pterygomaxillary implants were divided into three different types based on the anatomical structures the implants passed through.ResultsThe average age of the 180 patients was 69 (range: 39–89) years; 99 were men and 81 were women. All the patients exhibited 360 pterygomaxillary implant sites. However, during mimic implantation, 14 implant sites were excluded due to severe resorption of the tuberosity, very small pterygoid plates, or variations in the descending palatal artery configuration. Of the 346 pterygomaxillary implant sites, 24.0% (83/346), 40.7% (141/346), 22.0% (76/346), and 13.3% (46/346) were classified as Types I, IIa, IIb, and III, respectively.ConclusionsType II pterygomaxillary implants were the most commonly used in the novel classification. Different types of pterygomaxillary implants should follow specific designs and surgical strategies to achieve optimal outcomes.

Crestal Sinus Lift with the Hydrodynamic Technique: Prospective Clinical Study at 3 Years Follow-Up

Aim: This study aimed to evaluate the implant survival rate, marginal bone loss (MBL), and surgical complications in single dental implants placed in the atrophic posterior maxilla using a transcrestal sinus lift with injectable graft materials. Materials and Methods: A prospective longitudinal study was conducted at IRCCS San Raffaele, Milan, Italy. Fifty-four patients with single edentulous sites and residual bone heights < 5 mm were included. A transcrestal sinus lift was performed using non-cutting drills (Cosci’s technique) and xenogenic bone graft in gel form (Gel40, Tecnoss, Italy). Follow-up visits were at 1 week, 3 and 6 months, and annually for 3 years. Results: The implant survival rate was 98.04%, with one implant lost. MBL values were 0.71 ± 0.94 mm at 6 months, 1.00 ± 0.99 mm at 1 year, 1.03 ± 1.00 mm at 2 years, and 1.02 ± 1.01 mm at 3 years. Our ANOVA showed a significant MBL increase from 6 months to 1 year (p = 0.015), with no significant changes thereafter. Minimal surgical complications were observed, each occurring in 1.85% of cases. Conclusion: Transcrestal sinus lifts with injectable graft materials demonstrate high implant survival, acceptable MBL, and minimal complications, making it a reliable option for posterior maxilla rehabilitation.

Transalveolar sinus lifting using autogenous chin graft containing implant in atrophic posterior maxillary alveolar ridge

Abstract Background Posterior maxillary implant rehabilitation is a critical procedure because of the diminished bone quality and quantity, especially in severe atrophic posterior maxilla which affect the stability of the implant and raises the demand of the sinus floor elevation, bone augmentation and ensuring implant stability in order for the implant to succeed. Transalveolar sinus lifting is a valuable technique in reaching and augmenting the floor of the sinus without penetrating the sinus membrane or causing sinusitis and to avoid numerous surgical interventions. Patients and methods This is a prospective, interventional clinical study that was carried out on 10 adult patients who had missed posterior maxillary teeth and wanted to restore it, with less than 5 mm residual bone height and greater than 7 mm bone width which treated with transalveolar sinus lifting using corticocancellous bone block containing the implant from the chin bone. All patients are followed-up clinically and radiographically by cone beam computed tomography. Results Our technique was performed successfully in all cases without any signs of infection or sinusitis and all implants inserted were clinically stable after 6 months with radiographic significant increase in the bone height and density around the implants. Conclusion Transalveolar sinus lifting using press-fitted corticocancellous bone block containing implant from chin bone was found to be highly effective technique for posterior maxillary rehabilitation in severe atrophic posterior maxilla.

Comparative efficacy of osteotome versus CAS kit-assisted indirect maxillary sinus lift and immediate implant placement in posterior atrophic maxilla: A clinico-radiological study

Background: The aim of this study was to compare and evaluate clinical and radiological outcomes of conventional osteotome technique and CAS kit uses for indirect sinus lifting and immediate implant placement in atrophic posterior maxilla. Methods: A total of 20 patients aged <18 years in which 60% males and 40% of females were included in this study requiring implant prosthesis in atrophic (RBH > 3mm) posterior maxilla with a minimum width of 6mm were included in the study. They were randomly divided into two groups by computerised allocation into one group undergoing sinus lift with osteotome, and the other with CAS kit. Statistical analysis was done by using descriptive and inferential statistics. Qualitative data were analyzed using the Chi-square test. Dependent and independent variables were evaluated by the paired t-test and unpaired t-test respectively. A p<0.05 was set as the level of significance. Results: Mean duration for implant placement in the CAS group was 13.40±2.98 and in patients the osteotome group was 22.10±2.55. Mean primary stability in patients with CAS group was 44±6.14 and patients with osteotome group were 35.50±7.61. Mean amount of bone regeneration radiographic evaluation at three months in patients of CAS group was 4.99±0.86 and in patients of osteotome group was 5.59±1.21. The mean amount of bone regeneration radiographic evaluation at nine months in the CAS group was 5.53±0.77 and 6.34±1.11 in the osteotome group. Conclusions: CAS kit compared to osteotome was better in terms of operative time, primary stability, and marginal bone loss resulting in recommended modality.

Sling Suture Technique Used to Stabilize the Collagen Membrane on the Lateral Bone Window During Maxillary Sinus Floor Augmentation With a Lateral Approach: A Retrospective Case Series.

Maxillary sinus floor augmentation is a safe and predictable technique used to increase bone volume under sinus cavity for implant placement in atrophic posterior maxilla before implant placement. Despite conflicting results concerning the new bone formation rates with or without a barrier membrane, the benefits of using a collagen membrane to cover the lateral bone window has been demonstrated, in order to prevent bone substitute particles dislodgement that may occur from the sinus cavity through the sinus antrostomy towards the oral mucosa, and to significantly reduce the postoperative swelling and pain reactions. The purpose of this case series is to present a sling suture technique used to stabilize the collagen membrane against the lateral bone window so as to improve the bone substitute stability inside the sinus cavity. Maxillary sinus floor augmentation with lateral approach using sling suture technique to maintain the collagen membrane against the lateral bone window was performed in 17 patients (8 women/ 9 men, mean age: 58.2 years). Postoperative cone-beam computed tomography (CBCT) images up to 6-month follow-up were performed to control the bone graft stability at the level of the lateral antrostomy. The clinical postoperative pain and swelling were assessed through a Visual Analogue Scale (VAS) questionnaire from level 1 (low), level 5 (acceptable), to level 10 (high) at one week postoperative. No bone substitute displacement was observed for all clinical cases on the CBCT images at 6-month postoperative. The pain and swelling level observed at one-week post operative were significantly low (respectively 1.6±1.0/2.1± 0.9). Within the limits of this case series, the use of sling suture technique to maintain the barrier membrane at the level of the lateral bone window in case of maxillary sinus floor augmentation with lateral approach surgery revealed to be a predictable protocol to prevent bone substitute displacement outside the sinus cavity.

Influence of a mesial cantilever on stress, strain, and axial force in fixed partial dentures with a distally tilted implant in the atrophic posterior maxilla.

This study aimed to investigate whether the presence of a mesial cantilever influences the biomechanical behavior and screw loosening in fixed partial dentures (FPDs) with a distally tilted implant in the atrophic posterior maxilla and where to best place the distal implant. Two configurations of implant-supported four-unit FPDs were modelled using finite element analysis. Five interabutment distances were considered. The stress and strain distributions in the implants, abutments, and prosthetic screws were verified under occlusal loading. The development of the axial force on the abutments and screws was also examined. Two-sample t-tests were used to identify differences (P < 0.05). The von Mises stress distributions of the components in the two configurations were similar, as were the maximum plastic strains of the distal prosthetic screws, distal implants, and 30° abutments. The difference in the maximum plastic strains of the straight abutments was statistically significant. The preload of the 30° abutment screws was significantly reduced after the initial loading. In the absence of a mesial cantilever, the axial force on the straight abutments increased. However, when a mesial cantilever was used, the preload of the straight abutments was maintained, and the axial force on the prosthetic screws fluctuated less. The axial force fluctuation of the abutments gradually decreased as the interabutment distance increased. Mesial cantilever usage had minimal effect on stress or strain distribution in FPD implants, abutments, or prostheses. However, it helped resist screw loosening. The distal screw access hole was preferably positioned close to the prosthetic end.

New perspectives in the treatment of the severe atrophic posterior maxilla: interpositional sandwich osteotomy combined with sinus floor grafting - a novel technique

Purpose: Dental implant installation in the posterior maxilla depends fundamentally on the presence of an adequate bone quantity. Tooth loss in the posterior maxilla is followed by extensive loss of the alveolar ridge and increased maxillary sinus pneumatization that often makes implant installation difficult to achieve. Maxillary sinus floor augmentation is traditionally the common surgical technique to overcome this situation. When the deficiency in the vertical dimension relates more to severe ridge resorption, crestal ridge augmentation should also be considered. Posterior maxillary sandwich osteotomy combined with sinus augmentation, using inter–positional bone graft might be a viable option to address this problem. This study describes a successful implementation of this technique to solve a severe vertical osseous ridge defect under the sinus floor. Material and Methods: A two–stage lateral wall sinus floor augmentation combined with inter–positional sandwich osteotomy followed by the insertion of dental implants with adequate length and diameter was performed. Deproteinized natural bovine bone mineral (DBBM) covered by a resorbable collagen membrane were used. Rehabilitation of this area was completed by a standard prosthetic protocol. Results: As a result of completing the above procedure favourable bone mass and form was created to enable implant placement in positions that are optimal from a prosthetic and esthetic point of view in terms of reshaping the alveolar crest and normali- zing the interocclusal distance improving the crown–implant ratio. Conclusion: This case demonstrates a step–by–step illustration of an innovative technique for overcoming a vertical ridge defect combined with increased maxillary sinus pneumatization. It can be concluded that this novel technique is recommended to meet the dimensional requirements of bone augmentation both crestal and intrasinusal in severe atrophic posterior maxilla to achieve an improved alveolar plane, equalized crown–to–implant ratios, and a more favourable gingival shape.

Evaluation of crestal sinus floor elevation in cases exhibiting an oblique sinus floor with a residual bone height of 4.0–7.0 mm using Densah burs with simultaneous implant placement: a prospective clinical study

PurposeTo evaluate the effectiveness of using Densah burs for lifting the maxillary sinus membrane in cases with an oblique sinus floor with a residual bone height of 4–7 mm.MethodsThe study was conducted on 16 patients, comprising 9 males and 7 females, aged 25–60 years, split into two groups of 8 each: group I with a residual bone height of 4–5.5 mm below the sinus floor and group II with a residual bone height of 5.5–7 mm. Exclusion criteria included smokers, presence of systemic or metabolic conditions that contraindicate implant placement and a local sinus pathology. The study involved the use of Densah burs, using the osseodensification concept to elevate the sinus floor, along with simultaneous dental implant placement. The integrity of the sinus membrane was verified via clinical examination and a confirmatory cone beam computed tomography scan.ResultsThe study revealed that out of the 16 cases, one case had a sinus membrane perforation, confirmed clinically at the time of the operation. The study achieved a mean lift of 4.42 mm and a mean final seating torque of 35.5 N/cm. At the 1-year follow-up, all cases showed clinical success, with no signs of sinus pathology or complications.ConclusionsIn cases with oblique sinus floors and a residual bone height of 4–7 mm in moderately atrophic posterior maxilla, the osseodensification concept proved to be a safe and effective method for performing sinus lift procedures with simultaneous implantation.Graphical

How to Prevent and Manage Postoperative Complications in Maxillary Sinus Augmentation Using the Lateral Approach: A Review.

Maxillary sinus augmentation with a lateral approach is known to present more postoperative complications than other atrophic posterior maxilla treatment modalities because it is more invasive. These complications include infections that occur in the form of chronic or acute sinusitis. According to the literature, the frequency of these complications ranges from 3% to 5%. They can result from an inadequate management of intraoperative complications or from a poor evaluation of maxillary sinus particularities and pathology before the surgery. Therefore, the prevention of postoperative complications lies in the selection of cases that will allow for the identification and evaluation of infectious risk. Only a multidisciplinary approach that includes an implantologist, a rhinologist, and the treating physician will allow this. On the other hand, in infectious complication cases, the intervention of the otorhinolaryngologist (ENT) specialist is necessary. Based on the available literature and the author's experience, the methodology described in this article will allow for the prevention and management of postoperative complications related to this surgical technique.

Pterygoid and tuberosity implants in the atrophic posterior maxilla: A retrospective cohort study

Statement of problemRehabilitation of the partially or completely edentulous posterior maxilla using dental implants is a clinical challenge because of the presence of the maxillary sinus, as well as the low quality and quantity of bone in that region. In addition to bone augmentation procedures, posterior maxillary rehabilitation using implants includes their anchoring in bones such as the zygoma, pterygoid, and maxillary tuberosity, as well as in short implants. However, the performance of pterygoid and tuberosity implants in the atrophic posterior maxilla is unclear. PurposeThe purpose of this retrospective cohort study was to evaluate the survival of tuberosity and pterygoid implants in patients with posterior maxillary atrophy. Material and methodsA nonprobability convenient sample of patients who had received fixed prostheses on implants placed in the maxillary tuberosity or pterygoid regions was analyzed retrospectively. Demographic variables included sex (male, female) and age. Implant-related variables included surface characteristics, site of placement, implant design, length, diameter, and anteroposterior insertion angle. Prosthetic-related variables included the type of reconstruction for rehabilitation and loading protocols. Implant survival, complications, crestal bone loss, and follow-up intervals were also documented. Collected data were analyzed at both patient and implant levels. The demographics and implant characteristics of patients receiving pterygoid or tuberosity implants were analyzed with a statistical software program (α=.05). Survival analysis was estimated by using the nonparametric Kaplan-Meier curve. ResultsA total of 119 patients had 183 pterygoid or tuberosity implants inserted. Most implants in the pterygoid region (71.5%) were Ø4.1 mm (87.4%) and 15 mm in length (60.1%). The most common prostheses were complete maxillary reconstructions (49.2%) with late loading (74.3%). The average implant anteroposterior insertion angle was 60.8 degrees. The cumulative survival rate was 97.3% (n=178) during the mean follow-up period of 57 months (range 1 to 168 months). Among all implants placed, 2.7% failed (n=5) within 2 months of their placement. The statistically significant differences noted between tuberosity and pterygoid implants were related to design, surface characteristics, and loading. The average crestal bone loss was 1.5 mm. ConclusionsThe survival of the implants placed in the maxillary tuberosity and pterygoid regions was high in patients with posterior maxillary atrophy.

The Customized Alveolar Ridge-Splitting (CARS) Technique Combined with Guided Bone Regeneration or Sinus Elevation Augmentation in Maxillary Deficient Ridges.

Various techniques have been proposed to regenerate deficient ridges after tooth removal, including guided bone regeneration, block grafting, distraction osteogenesis, and ridge splitting. However, these procedures are technique-sensitive and often present complications which prevent reconstruction of the deficient ridge and implant placement. In an atrophic anterior or posterior maxilla, these techniques often fail to produce satisfactory long-term outcomes due to the poor bone quality, pneumatization of the maxillary sinus, and the highly cosmetic patient demands. The customized alveolar ridge-splitting (CARS) technique was introduced to improve outcomes and minimize the risk of complications. The synergistic combination of this technique with another augmentation procedure-including lateral window sinus augmentation and guided bone regeneration-allows implant placement into ridges with deficient bone volume both vertically and horizontally. This study presents two case reports that were successfully treated with the CARS technique and additional augmentation techniques to treat severely atrophic ridges in the anterior and posterior maxilla.

Short‐term performance of unilateral zygomatic implants: A case series

AbstractThe aim of this investigation is to contribute to clarify whether zygomatic unilateral implants are a feasible alternative for the rehabilitation of the atrophic maxilla. Six consecutive, unilaterally edentulous patients who received zygomatic implants gave their consent to enter this retrospective observational study. Fixtures were inserted according to the Zygomatic Anatomy‐Guided Approach and loaded with functional screwed restorations. All patients were compliant with their scheduled follow‐up appointments. Six tapered implants were considered, mostly (80%) 4.4 mm diameter 40–50 mm long. These fixtures had been in place for an average of 4.1 years (range: 5–144 months). No implant failures were observed, and continuous fixed‐prosthesis function was achieved throughout the follow‐up period with no loosening or fracture of prosthetic screws. Patients were satisfied with the treatment and experienced only minor complications. Unilateral zygomatic implants seem to be a feasible alternative that diminishes morbidity and treatment times with high‐survival rates for patients with atrophic posterior maxilla.

Using Platelet-Rich Fibrin in Combination With Allograft Bone Particles Can Induce Bone Formation in Maxillary Sinus Augmentation

Sinus pneumatization secondary to posterior maxillary tooth extraction can hinder proper implant installation. Maxillary sinus floor augmentation is a surgical procedure that has been proposed to overcome this issue. The aim of this study was to evaluate and compare the histomorphometric outcomes of sinus floor elevation using allograft bone particles with or without platelet-rich fibrin (PRF). This randomized clinical trial included patients scheduled for maxillary sinus floor elevation in the Implant Department of Mashhad Dental School. Healthy adults with an edentulous maxilla and residual alveolar bone height of 3mm or less were eligible to participate and were randomly allocated to intervention (A) or control (B) groups. Bone biopsies were obtained 6months postoperatively. The predictor variable was using a PRF membrane for maxillary sinus augmentation. In group A, sinus floor elevation was performed using PRF combined with bone allografts, while in group B only allograft particles were used. The primary outcome variables were the recorded postoperative histologic parameters, as in the area of newly formed bone, new bone marrow, and residual graft particles (μm2). The secondary outcome variables were the radiographically measured postoperative bone height and width at the graft site. Age and sex. Independent sample t-test was employed to compare the postoperative histomorphometric parameters between groups A and B. P value ≤ .05 was considered statistically significant. A total of 20 patients (10 per group) completed the study. The mean rate of new bone formation was 43.25±5.22% in group A and 38.25±7.01% in group B. This difference was statistically insignificant (P=.087). The mean amount of newly formed bone marrow was significantly more in group A compared to group B (6.81±2.19% vs 10.23±4.49%; P=.044). The average amount of remaining particles was also significantly less in group A patients (9.35±3.43% vs 13.18±3.67%; P=.027). Incorporating PRF as an adjunctive grafting material results in fewer residual particles of allograft and in more bone marrow formation and may serve as a treatment option for developing the atrophic posterior maxilla.

One-Month Postoperative Reentry for Maxillary Sinus Floor Augmentation After a Large Sinus Membrane Perforation: A Retrospective Clinical and Radiographic Analysis.

The aim of this retrospective analysis was to evaluate the clinical and radiographic results of a shortened protocol (using a lateral approach) for early surgical reentry, following a large sinus membrane perforation that occurred during maxillary sinus augmentation (lateral approach), for the rehabilitation of patients with an atrophic posterior maxilla. Between May 2015 and October 2020, seven patients underwent reentry surgery using a lateral approach protocol 1 month after a large sinus membrane perforation during maxillary sinus floor augmentation with lateral approach surgery. All patients presented a residual under-sinus bone height < 3 mm in the posterior maxilla. The sinus membrane was elevated during the reentry surgery, without any difficulty for any patient, using manual blunt elevators or piezoelectric devices, and the sinus floor height was augmented with bone substitute particles. No further perforations were made, and no complications were recorded during the follow-up period from 18 months to 6 years. The 1-month waiting period after the initial sinus surgery allows easy sinus membrane elevation and a lack of complications. This timing could be a feasible option for surgical reentry after a large sinus membrane perforation occurs. Int J Periodontics Restorative Dent 2023;43:241-246. doi: 10.11607/prd.6463.

Vertical and horizontal ridge augmentation using customized three-dimensionally printed polycaprolactone mesh in atrophic posterior maxillae: a case report.

Polycaprolactone has exhibited expediency as a biomaterial for bone regenerative procedures preclinically. The present report of the two clinical cases in the posterior maxilla is the first to describe clinical application of a customized 3D printed polycaprolactone mesh for alveolar ridge augmentation. Two patients needing extensive ridge augmentation procedures for dental implant therapy were selected. Polycaprolactone meshes were virtually designed, 3D printed and applied in combination with a xenogeneic bone substitute. Cone-beam computed tomography was taken pre-operatively, immediately after the surgery, and 1.5 to 2 years after the delivery of implant prostheses. The serial cone-beam computed tomography images were superimposed to measure the augmented height and width at 1 mm increments from the implant platform to 3 mm apically. After 2 years, the mean [maximum, minimum] bone gain was 6.05 [8.64, 2.85] mm vertically and 7.77 [10.03, 6.18] mm horizontally at 1 mm below the implant platform. From immediately postoperative to 2 years, there was 14 % reduction of augmented ridged height and 24 % reduction of augmented width at 1 mm below the platform. All implants placed in augmented sites were successfully maintained until 2 years. The customized Polycaprolactone mesh might be a viable material for ridge augmentation in the atrophic posterior maxilla. This needs to be confirmed through randomized controlled clinical trials in future studies.

Residual Bone Height and New Bone Formation after Maxillary Sinus Augmentation Procedure Using Biomaterials: A Network Meta-Analysis of Clinical Trials.

Different factors may affect new bone formation following maxillary sinus floor augmentation for the rehabilitation of posterior edentulous maxilla. The purpose of this study was to determine the influence of residual bone height (RBH) on new bone formation after lateral sinus augmentation utilizing different biomaterials, through a network meta-analysis (NMA). PUBMED, Scopus, and Web of Science electronic databases were searched until 31 December 2022 to obtain relevant articles. A hand search was also conducted. Randomised controlled studies on maxillary sinus augmentation comparing different grafting materials in patients with atrophic posterior maxilla, in need of prosthetic rehabilitation, were included. The risk of bias was assessed following the guidelines of the Cochrane Collaboration. The primary outcome was new bone formation (NBF), assessed histomorphometrically. The statistical analysis was performed by splitting the data according to RBH (<4 mm and ≥4 mm). A total of 67 studies were eligible for conducting NMA. Overall, in the included studies, 1955 patients were treated and 2405 sinus augmentation procedures were performed. The biomaterials used were grouped into: autogenous bone (Auto), xenografts (XG), allografts (AG), alloplasts (AP), bioactive agents (Bio), hyaluronic acid (HA), and combinations of these. An inconsistency factor (IF) seen in the entire loop of the XG, AP, and Bio+AP was found to be statistically significant. The highest-ranked biomaterials for the <4 mm RBH outcome were XG+AG, XG+AP, and Auto. Similarly, the surface under the cumulative ranking curve (SUCRA) of biomaterials for ≥4 mm RBH was Auto, Bio+XG, and XG+Auto. There is no grafting biomaterial that is consistently performing better than others. The performance of the materials in terms of NBF may depend on the RBH. While choosing a biomaterial, practitioners should consider both patient-specific aspects and sinus clinical characteristics.

Short Implants versus Standard Implants and Sinus Floor Elevation in Atrophic Posterior Maxilla: A Systematic Review and Meta-Analysis of Randomized Clinical Trials with ≥5 Years' Follow-Up.

Background and objectives: The aim of this systematic review with meta-analysis was to assess the performance of short implants in comparison with standard implants and sinus floor elevation in atrophic posterior maxilla. Materials and methods: The protocol of the study was registered in the PROSPERO database (CRD42022375320). An electronic search on three databases (PubMed, Scopus, Web of Science) was performed to find randomized clinical trials (RCTs) with ≥5 years' follow-up, published until December 2022. Risk of bias (ROB) was calculated using Cochrane ROB. A meta-analysis was performed for primary (implant survival rate, ISR) and secondary outcomes (marginal bone loss, MBL; biological and prosthetic complications). Results: Of 1619 articles, 5 RCTs met the inclusion criteria. The ISR showed a risk ratio (RR) of 0.97 [0.94, 1.00] (CI 95%), p = 0.07. The MBL indicated a WMD of -0.29 [-0.49, -0.09] (CI 95%), p = 0.005. Biological complications showed a RR of 0.46 [0.23, 0.91] (CI 95%), p = 0.03. Prosthetic complications showed a RR of 1.51 [0.64, 3.55] (CI 95%), p = 0.34. Conclusions: The available evidence suggests that short implants might be used as an alternative to standard implants and sinus floor elevation. After 5 years, in terms of ISR, standard implants and sinus floor elevation showed a higher survival rate comparted to short implants, although statistical significance was not achieved. Future RCTs with long-term follow-up are needed to draw a clear conclusion on the advantages of one method over another.

Removal of dental implants displaced into the maxillary sinus: a retrospective single-center study

BackgroundThe use of dental implants in the prosthetic rehabilitation of the posterior atrophic maxilla might be a challenge procedure because of low bone quantity and quality. This study aimed to report cases of implant displacement or migration into the maxillary sinus treated from 2008 to 2021.Materials and methodsAll patients with unintentional insertion and/or displacement of dental implants into the maxillary sinus cavity that underwent surgical removal were included. Variables assessed included the patients’ characteristics, past medical history, clinical and radiological findings at presentation, surgical approach (transoral, transnasal, combined), and outcome.ResultsA total of forty patients (23 male, 17 female) underwent surgical removal of dental implant displaced in the maxillary sinus. The mean age was 52,3 + 11,3 years. Seven patients presented with oro-antral fistula (OAF). In 15 cases, an ostium obstruction was diagnosed. Twenty-five patients underwent transoral surgery under local anesthesia. Eleven patients were treated solely via transnasal endoscopic approach, and four patients who had an associated OAF underwent surgery through a combined transnasal and transoral approach. All patients healed uneventfully without complications.ConclusionThese results and recent literature validate that transoral and transnasal approach, or a combination of these procedures, can be used safely to treat complications following displacement/migration of dental implants in the maxillary sinus. Early surgical removal minimizes sinus inflammation and prevents more invasive procedures. Each procedure presents specific indications that must be carefully evaluated prior to treatment choice to optimize intervention outcomes.