Risk factors in lateral window sinus elevation surgery

Management of Oral Surgery-Related Complications

This article reviews the optimal management of oroantral fistulas, implants protruding into the maxillary sinus, implants completely displaced into the sinus(es), and infected bone grafts used for sinus augmentation. For each scenario, multidisciplinary management strategies will be considered based on whether there is concurrent infectious odontogenic sinusitis. A multidisciplinary approach with oral surgeons and otolaryngologists is often mandatory to ensure optimal therapeutic outcomes.

Prevention and management of intra-operative complications in maxillary sinus augmentation: A review

Maxillary sinus floor elevation is usually performed in two different ways: the lateral approach involves the creation of a bony window on the maxillary sinus lateral wall, providing direct access to the sinus cavity for membrane elevation and subsequent graft placement, and the transcrestal approach is considered less invasive. The aim of this article is to describe, based on the literature, how to anticipate, avoid, and manage the intraoperative complications that can occur with both approaches. For both approaches, the most common complication is the sinus membrane perforation. For the lateral approach, an average frequency ranging from 15.7% to 23.1% is reported, but because of the better visibility, their management will be easier compared to the transcrestal approach. Mean perforation rate reported for the transcrestal approach is lower (3.1%-6.4%), but it should be noted that a significant number of perforations cannot be detected and managed given the blind nature of this technique. Anatomical parameters such as sinus width and buccal wall thickness may be a risk factor for one approach and not the other. As it is impossible to assess the resistance of the Schneiderian membrane, the transcrestal approach is more likely to lead to infectious complications in the event of perforation. Others, such as the risk of vascular damage, are encountered only with the lateral approach, which can be prevented easily by dissecting the alveolo-antral artery. For both approaches, prevention is essential and consists in analyzing the anatomy, mastering the surgical technique, and collaborating with the ENT to manage the essentially infectious consequences of intraoperative complications.

Novel use of dynamic navigation for guiding a piezoelectric device during window osteotomy for maxillary sinus floor elevation in complex clinical scenarios

In patients with severe atrophy of the posterior maxilla requiring lateral maxillary sinus floor elevation (MSFE), the window location and size are commonly designed according to the future implants and anatomical conditions. A window osteotomy becomes challenging when there is an extended edentulous space in the maxilla with no reference from the natural dentition, or when the surgical site involves anatomical variations, for example in the course of a large vessel or a sinus septum. Through preoperative planning and real-time visualization, the application of dynamic navigation allows an accurate location, optimal dimension, and customized shape during lateral window osteotomy. This article introduces a digital protocol for ensuring an accurate and safe window osteotomy for MSFE in complex clinical scenarios, by integrating dynamic navigation and a piezoelectric device.

Does alveolar ridge preservation reduce the need for sinus floor elevation: A comparative study to spontaneous healing

INTRODUCTION

In cases of atrophy in the maxillary posterior region, characterized by reduced vertical bone volume, implant placement becomes challenging. Augmentation procedures like sinus lifts are often needed to address insufficient bone volume. This study aims to explore if alveolar ridge preservation, using a bovine bone substitute and a porcine collagen membrane, significantly decreases the need for sinus lifts compared to natural wound healing after tooth extraction.

MATERIALS AND METHODS

In this comparative clinical study, 40 patients requiring a total of 53 extractions were assigned to one of the following groups: a test group with bovine bone substitute material (Straumann® XenoFlex) and a porcine collagen membrane (Jason® membrane), or a control group with spontaneous socket healing. After 6 months, digital volume tomography was performed for implant planning.

RESULTS

For seven patients from the control group (n = 22 extracted sites) sinus lift augmentations were performed while only four sinus lift procedures were performed in the test group (n = 31 extracted sites), indicating a higher need for sinus augmentation procedures in the control group, however not statistically different on a p value of 0.05 (p = 0.168). In the control group, the mean value of the radiographically measured bone height (mesial and distal) was 11.13 ± 2.12 mm preoperatively before tooth extraction, while it was 11.3 ± 2.17 mm postoperatively after implant placement. In contrast, the mean value in the test group was 11.78 ± 3.09 mm preoperatively and 11.92 ± 2.79 mm postoperatively. Statistical analysis revealed no significant difference between the two groups (odds ratio 0.32; 95% CI: 0.08, 1.26; p = 0.951). The implant survival rate in the control group was 100%, compared to 96.77% in the test group.

CONCLUSION

Within the limits of this study, the use of bovine bone substitute and a porcine resorbable membrane after tooth extraction in the posterior maxilla seems to reduce the need for sinus augmentation in comparison to spontaneous healing although the difference was not statistically significant. Additionally, the Alveolar Ridge Preservation in the test group made external sinus floor elevation unnecessary compared to the control group. The change in radiographically measured bone height pre- and postoperatively showed no significant difference between the two groups.

Patient and implant-related risk factors for implant failure of one-stage lateral sinus floor elevation: A 2- to 10-year retrospective study

OBJECTIVES

This retrospective study aimed to evaluate the early and late implant failure rates of one-stage lateral sinus floor elevation (LSFE) and to identify the patient and implant-related risk factors associated with these failures.

MATERIALS AND METHODS

All patients treated with one-stage LSFE from January 2014 to December 2021 were evaluated for inclusion. A total of 618 patients with 936 implants met the inclusion criteria. Clinical and radiographic information about patient and implants was collected. Univariate and multivariate Cox proportional hazards frailty regression models were performed to identify risk factors for early and late implant failure.

RESULTS

The cumulative implant survival rate was 95.62% (95% CI 93.90%-97.68%), with 16 early implant failures and 25 late implant failures. The Cox analysis indicated that ≤3 mm residual bone height (RBH) was associated with a higher early failure rate. For late implant failure, smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors. Narrow sinus ostium, long infundibulum, and flat thickening of Schneiderian membrane might be non-independent risk factors for late implant failure. No significance was found in other variables, including age, periodontitis history, implant characteristics (position, diameter, length, protrusion length, marginal bone loss), surgeon experience, healing time, opposing dentition, and prosthesis.

CONCLUSIONS

One-stage LSFE is a predictable treatment for patients with atrophic maxilla. ≤3 mm RBH increased the risk of early implant failure, while smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors for late implant failure.

Collaboration between otolaryngologists and oral surgeons in maxillary sinus elevation planning

BACKGROUND

The collaboration between otolaryngologists and dental providers is crucial for the planning and execution of maxillary sinus elevation (MSE) procedures, which are integral to successful dental implant placements.

PURPOSE

This article examines the essential role of otolaryngological assessments in identifying potential sinonasal risks that could impact the outcomes of MSE.

MATERIALS AND METHODS

A comprehensive narrative review of existing literature was conducted.

DISCUSSION

The review underscores the importance of thorough preoperative evaluations, including patient history, computed tomography (CT) or cone-beam CT (CBCT) scans, and nasal endoscopy, to mitigate sinonasal health risks. It details various clinical scenarios and patient assessments, emphasizing a systematic approach to diagnosing and managing sinonasal conditions proactively. The discussion reveals that while some sinus conditions may not significantly affect MSE success, conditions impacting mucociliary clearance and sinus drainage are critical risk factors requiring otolaryngological intervention. Additionally, the article introduces a grading system to assist clinicians in identifying patients who would benefit from otolaryngological evaluations prior to MSE.

CONCLUSION

This review highlights the value of interdisciplinary collaboration and standardized protocols in enhancing the predictability and safety of MSE procedures, ultimately improving patient outcomes.

Anatomical Factors of the Anterior and Posterior Maxilla Affecting Immediate Implant Placement Based on Cone Beam Computed Tomography Analysis: A Narrative Review

BACKGROUND

The aim of this narrative review was to provide insights into the influence of the morphological characteristics of the anatomical structures of the upper jaw based on cone beam computed tomography (CBCT) analysis on the immediate implant placement in this region.

MATERIAL AND METHODS

To conduct this research, we used many electronic databases, and the resulting papers were chosen and analyzed. From the clinical point of view, the region of the anterior maxilla is specific and can be difficult for immediate implant placement.

FINDINGS

Anatomical structures in the anterior maxilla, such as the nasopalatine canal and accessory canals, may limit and influence the implant therapy outcome. In addition to the aforementioned region, immediate implant placement in the posterior maxilla may be challenging for clinicians, especially in prosthetic-driven immediate implant placement procedures. Data presented within the recently published materials summarize the investigations performed in order to achieve more reliable indicators that may make more accurate decisions for clinicians.

CONCLUSION

The possibility for immediate implant placement may be affected by the NPC shape in the anterior maxilla, while the presence of ACs may increase the incidence of immediate implant placement complications. The variations in IRS characteristics may be considered important criteria for choosing the implant properties required for successful immediate implant placement.

Surgical Drainage and Simultaneous Sinus Floor Augmentation in Patients with Chronic Maxillary Sinusitis

Chronic maxillary sinusitis accompanied by severe thickening of the sinus mucosa, blockage of the ostium, and patient-reported symptoms requires preoperative assessment and treatment by an otolaryngologist before maxillary sinus floor augmentation (MSFA). Prescription of antibiotics and nasal saline irrigation are the first choice of treatment; however, endoscopic sinus surgery is considered when the treatment's effect is limited and drug resistance is observed. Nevertheless, MSFA performed in the presence of sinus pathologies have been reported to have favorable results when the lesions are managed properly. This report presents cases of two patients who required MSFA but were diagnosed with chronic maxillary sinusitis (case 1 with nasal sinusitis and case 2 with dental sinusitis). After 2 weeks of antibiotic therapy, endoscopic surgery was recommended due to minimal changes in the size of the sinus lesion; however, the patients refused because of improved self-reported symptoms. Therefore, intraoral surgical drainage was planned as an alternative treatment. A large bony window was prepared at the lateral wall of the maxillary sinus, and a long intentional incision was made to improve access for the suction tip in various directions and depths into the sinus cavity. Thorough suction of the purulent exudate and saline irrigation were performed through this access. The size of the perforated area was reduced along with the elevation of the Schneiderian membrane from the sinus floor, and simultaneous bone grafting with implant placement was performed. Prosthesis was delivered after 6-8 months. At 1-year follow-up after loading, favorable outcomes of implant survival and maintenance of augmented bone height were observed, with no recurrence of postoperative sinusitis. Within the limitations of the present case report, thorough sinus drainage and saline irrigation during maxillary sinus floor augmentation resolved sinus infection in patients with chronic maxillary sinusitis with short-term clinical outcomes.

Croco Eye Technique: Mucous Retention Cyst Excision with Immediate Open Sinus Lift-A Retrospective Cohort Study

Objectives: A mucous retention cyst is a common, asymptomatic lesion that may cause complications during or after the sinus lift procedure. The goal of this study is to assess the effectiveness of the Croco Eye Technique (CET), which allows simultaneous excision of the cyst and sinus floor elevation. Methods: The technique was thoroughly described in two versions, and the group of 33 patients was analyzed. Patients who qualified for this procedure had insufficient alveolar ridge height, and their CBCT showed radiological images typical for retention cysts. Analyzed parameters included the version of CET, demographic data, anatomical parameters, intraoperative complications, recurrence of the cyst, success rate of the sinus lift and implants, and the follow-up period. Results: Out of the 33 cases, 9 were of the primary version (27.27%) and 24 of the final version (72.73%). The average height of a retention cyst was 24.05 mm, with the average alveolar ridge height of 1.86 mm. In three cases (9.09%), implants were placed immediately. The prevalence of uncontrolled Schneiderian membrane perforation was reduced from 55.56% to 4.17% between the primary and final versions. The cyst's recurrence rate was 3.13%. The implant survival rate was 100%. The mean follow-up period was 48.625 months (max 110 months). Conclusions: The Croco Eye Technique, despite the perforation of the Schneiderian membrane, enables successful sinus lift and implantation with a success rate of 100%. Excision of the retention cyst, which is the cause of perforation, allows for limiting the risk of the cyst's recurrence.

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.

A Clinical Approach for the Removal of a Large Antral Pseudocyst with Simultaneous Maxillary Sinus Augmentation: A Case Series

For a large benign lesion within the maxillary sinus, such as an antral pseudocyst, maxillary sinus floor augmentation is more commonly performed using a two-stage approach. This involves first removing the lesion, and then, re-entry following several months of healing. In this case series, we described the "one-bony-window" approach, which is a technical surgical modification of the previous one-stage approach, for simultaneous cyst removal and maxillary sinus floor augmentation. Four patients with large maxillary antral pseudocysts were included. The "one-bony-window" approach involves the preparation of a large window opening of approximately 15 mm × 20 mm at the lateral wall. A mesiodistally extended intentional perforation was made in the upper part of the exposed membrane to enhance the access for instrumentation. The antral pseudocyst was removed in its entirety without being deformed to prevent rupture or leakage of the cystic contents. Subsequent detachment and elevation of the Schneiderian membrane at the sinus floor significantly reduced the perforation site, and bone grafting with implant placement was performed simultaneously. This alleviated the need to surgically repair the perforation. The lateral opening was either uncovered or repositioned using bony window lids. Healing abutments were connected after six months, and the final prosthesis was placed after two months. At the 1-year follow-up, the antral pseudocysts had resolved with no specific recurrence, and the stability of the augmented sinus was maintained with excellent implant survival. Within the limitations of our findings, the "one-bony-window" technique can be suggested for the simultaneous removal of large antral pseudocysts and maxillary sinus floor augmentation with favorable clinical outcomes.

Maxillary bone augmentation with calvarial bone graft for immediate full-arch rehabilitation: Insights from a 10-year proof-of-concept retrospective analysis

OBJECTIVE

Evaluate the long-term outcomes of full-arch rehabilitation using immediate dental implant placement and continuous functional loading with full-fixed dental prostheses (FFDPs).

MATERIALS AND METHODS

Fifty-six patients received temporary implants (n = 327) at maxillary augmentation with calvarial bone. A provisional acrylic FFDP was immediately loaded onto these implants. After 6 months, the temporary implants were replaced with definitive implants (n = 326) and immediately loaded with a second provisional FFDP (N = 55). Subsequently, a baseline radiograph was taken following a 6-month healing period. The second bridge was then substituted with a definitive FFDP. Primary outcomes included peri-implant marginal bone level (MBL) and definitive implant survival. Secondary outcomes evaluated provisional implant and prostheses survival, complications, and patient satisfaction.

RESULTS

The provisional implants had a survival rate of 97.9%. One patient was excluded from further analysis due to loss of temporary implants and first FFDP. The definitive implant survival rate after 10 years was 92.2%, with a moderate but significant decrease in MBL between baseline radiography and 10 years later (-0.08 ± 0.18 vs. -0.24 ± 0.44). However, large individual variations were observed, with 65.8% of implants showing no bone loss and 9.2% showing loss ≥0.5 mm. Sinusitis was experienced by 14.3% of patients upon surgery. Patient satisfaction was high or reported no issues after protocol completion (80%). One patient lost all six definitive implants and definitive FFDP 8.2 years after implant placement.

CONCLUSIONS

The described protocol can be regarded as a long-term, highly successful method for full-arch rehabilitation of atrophied maxillae while enabling continuous masticatory and speaking functionality.

Osseodensification versus lateral window technique for sinus floor elevation with simultaneous implant placement: A randomized clinical trial on patient-reported outcome measures

OBJECTIVES

To compare patient-reported outcome measures and additional surgical outcomes after sinus floor elevation (SFE) with osseodensification (OD) versus lateral window (LW), both with simultaneous implant placement.

MATERIALS AND METHODS

Twenty participants requiring single-implant rehabilitation with residual bone height (RBH) ≤4 mm were enrolled. Pain experience, quality of life (QoL) via the Oral Health Impact Profile-14 (OHIP-14), analgesics intake, and other symptoms were self-reported for a week on a daily basis. Surgery duration, complications, and implant stability quotient at baseline (ISQ T0 ) and after 6 months (ISQ T6 ) were registered. Participants were followed up for 1 year.

RESULTS

From Day 0 (day of surgery) to Day 3, pain experience was significantly lower (p < 0.05) in the OD group. OHIP-14 score was significantly lower (p < 0.05) in the OD group on all postoperative days, except on Day 5. Average analgesics intake was significantly lower (p < 0.001) in the OD group. Surgery mean duration was significantly higher (p < 0.001) in LW compared to OD (71.1 ± 10.4 vs. 32.9 ± 5.3 min). After osseointegration period, all implants were successfully restored with screw-retained crowns.

CONCLUSIONS

Within the limitations of this study, it can be concluded that OD and LW techniques were similarly effective in SFE with simultaneous implant placement when RBH ≤ 4 mm. However, OD significantly outperformed LW in pain experience, impact on self-perceived QoL, surgery duration, postoperative edema, and analgesics intake.

Sinus floor augmentation using crestal approach in conjunction with hydroxyapatite/cross-linked collagen sponge: A pilot study

BACKGROUND

Different biomaterials were suggested for sinus floor augmentation (SFA). Recently, new materials were launched showing true bone formation without remnants.

PURPOSE

The aim of this prospective study was to evaluate an hydroxyapatite-based, sugar cross-linked collagen sponge (OSSIX™ Bone) in transcrestal SFA (t-SFA).

MATERIALS AND METHODS

Twenty-four patients with edentulous posterior maxilla and residual bone height (RBH) >4 mm underwent t-SFA with OSSIX™ Bone as grafting material and simultaneous implant placement. The implant Stability Quotient (ISQ) was measured by resonance frequency analysis (RFA) directly after implant insertion and at 6 months. Differences in bone height (BH) and volume were determined in CBCT and x-rays at baseline versus 1 year of follow-up. Graft volume was evaluated by tridimensional reconstructions. Linear regression analysis was used to evaluate the effect of bucco-palatal sinus dimension, RBH, and length of the implant protruding (PIL) into the sinus, on the graft height (GH) changes up to 1 year, and on the graft volume at 1 year. Autocorrelation between time lag and augmented bone volume was evaluated through time series analysis correlograms. Health-related quality-of-life outcomes were captured.

RESULTS

Twenty-two patients completed the study. The mean RBH measured at baseline was 5.81 ± 2.2 mm. The mean graft volume was 1085.8 ± 733.4 mm3 . The mean GH, measured in the immediate post-operative period, at 6 and 12 months respectively, was 7.24 mm ±1.94; 6.57 mm ± 2.30; 5.46 mm ± 2.04. The mean ISQ measured after the implant placement was 62.19 ± 8.09, and 6 months later was 76.91 ± 4.50. There was a significant correlation between buccolingual dimension and graft volume at 1 year. Neither buccolingual volume nor RBH had a significant effect on GH change, while the PIL showed a significant positive correlation (P = 0.02 and P = 0.03 at 6 and 12 months, respectively). The correlograms indicated no significant correlation, meaning that there is no tendency for graft volume to increase or decrease over time, therefore suggesting graft stability, at least up to one year of follow-up. 86% of patients had no chewing interference.

CONCLUSION

Within the limitations of the study, OSSIX™ Bone could be considered a valid material for SFA due to its manageability and its positive results in promoting new bone formation with long-term stability. T-SFA is confirmed as a less invasive and less painful method.

Is it safe and effective to extract impacted maxillary tooth adjacent to maxillary sinus via submaxillary sinus membrane space approach?-a randomized controlled trial

OBJECTIVE

To evaluate the clinical outcomes following extraction of impacted maxillary tooth adjacent to maxillary via submaxillary sinus membrane space approach.

MATERIALS AND METHODS

Seventy-two patients were enrolled in our study. The positions of the maxillary impacted tooth were confirmed by cone-beam computed tomography (CBCT). Cases were randomly divided into two groups: the "submaxillary sinus membrane space approach" was applied in the new method (NM) group, and the conventional "avoid maxillary sinus membrane exposure" strategy was executed in the traditional method (TM) group. The clinical and follow-up data were recorded.

RESULTS

The duration of the procedure in the TM group was significantly longer than those in the NM group (P < 0.05). Four teeth were accidentally displaced into the maxillary sinus with MSM perforation. The MSM perforation rate was slightly higher in the TM group than in the NM group, however, without significant difference between the two groups (8/36 vs. 3/36, P = 0.19). The maxillary sinus membrane perforation was associated with the displacement of tooth into the maxillary sinus (OR = 16.2, P = 0.026). The root tip exposure of the adjacent tooth was significantly higher in the TM group than in the NM group (10/36 vs. 1/36, P = 0.006). The incidence of reduced pulp vitality of the adjacent tooth was significantly higher in the TM group (10/36 vs. 1/36, P = 0.006), and it was associated with the exposure of the root tip intraoperatively (OR = 456.5, P < 0.001). The incidence of external root resorption was significantly lower in the NM group, and there was no significant association with the root exposure intraoperatively (OR = 3.7, P = 0.47).

CONCLUSIONS

Submaxillary sinus membrane space approach is a safe and efficient approach in extraction of impacted maxillary tooth. It is an alternative way for cases which are in close proximity to the maxillary sinus.

CLINICAL RELEVANCE

A novel method to extract impacted maxillary tooth adjacent to maxillary sinus.

The Effectiveness and Practicality of a Novel Barrier Membrane for the Open Window in Maxillary Sinus Augmentation with a Lateral Approach, with Risk Indicators for Bone Graft Displacement and Bone Height Decrease: A Prospective Study in Humans

Maxillary sinus augmentation with a lateral approach (MSA) is a well-established treatment. In this prospective study, we evaluated risk factors for postoperative bone graft displacement and reported the clinical application of long-term resorbable L-lactic acid/-caprolactone (PLA/PCL) as a barrier membrane to cover the open window in the lateral wall in MSA. Twenty-four patients underwent MSA according to the relevant criteria; CT data obtained before and 1 week (1 w) and 5-6 months (5 m) post-MSA, bone height changes, bone height reduction rates at 1 w and 5 m post-MSA, bone graft displacement measurements, and risk factors were examined. All patients showed bone height increments (p < 0.005). However, no difference was observed between 1 w and 5 m post-MSA. Bone graft displacement was observed in eight patients; the reduction rate from 1 w to 5 m post-MSA was 8.38% ± 4.88%. Sex, septa, maxillary sinus floor-palatal bone distance, and maxillary sinus floor-maxillary ostium distance were associated with bone graft displacement (p < 0.05). The height from the maxillary sinus floor to the palatal bone and the sinus angle influenced the augmentation degree (p < 0.05). The PLA/PCL membrane is compared favorably with other membranes and may be useful as a barrier membrane for the MSA open window.

Maxillary sinus floor augmentation: a review of current evidence on anatomical factors and a decision tree

Maxillary sinus floor augmentation using lateral window and crestal technique is considered as predictable methods to increase the residual bone height; however, this surgery is commonly complicated by Schneiderian membrane perforation, which is closely related to anatomical factors. This article aimed to assess anatomical factors on successful augmentation procedures. After review of the current evidence on sinus augmentation techniques, anatomical factors related to the stretching potential of Schneiderian membrane were assessed and a decision tree for the rational choice of surgical approaches was proposed. Schneiderian membrane perforation might occur when local tension exceeds its stretching potential, which is closely related to anatomical variations of the maxillary sinus. Choice of a surgical approach and clinical outcomes are influenced by the stretching potential of Schneiderian membrane. In addition to the residual bone height, clinicians should also consider the stretching potential affected by the membrane health condition, the contours of the maxillary sinus, and the presence of antral septa when evaluating the choice of surgical approaches and clinical outcomes.

The Bone Bridge Technique Utilizing Bone from the Lateral Wall of the Maxillary Sinus for Ridge Augmentation: Case Reports of a 1-7 Year Follow-Up

The post-extraction socket of a periodontally compromised tooth/implant is oftentimes accompanied by a very wide-deep alveolar ridge defect. The commonly utilized treatment is ridge preservation followed by delayed implant placement 4 to 6 months after extraction. In the four cases presented in this study, a novel technique of utilizing a bone block obtained from the lateral wall of the maxillary sinus is introduced. Due to the severe localized vertical ridge deficiency, an intraoral autogenous bone block was obtained from the ipsilateral sinus bony window. After the obtained bone block was properly trimmed, it was fixed in the form of a bridge over the vertical defect by the press-fit method. In two cases, the gap between the autogenous bone and defect was filled with a particulate synthetic bone graft, and in another two cases, the gap was left without grafting. All cases were covered with a resorbable collagen membrane. At the time of re-entry after 5 to 6 months, the bone bridge was well incorporated beside the adjacent native bone and helped by the implant placement. Uncovering was performed after 3 to 6 months, and prostheses were delivered after 2 months. Oral function was maintained without any change in the marginal bone level even after the 1- to 7-year post-prosthesis delivery. This case series showed that the bone bridge technique performed using an ipsilateral sinus bony window for a localized vertical deficiency of a post-extraction socket can be used for successful vertical ridge augmentation (VRA).

How to avoid intraoperative and postoperative complications in maxillary sinus elevation

Maxillary sinus floor elevation, via the lateral approach, is one of the most predictable bone augmentation procedures performed in implant dentistry. but both intra- and postoperative complications can occur, and some of them are severe. Our aim is as follows: To review the pertinent literature on the topic, especially assessing the risk factors related to complications. To give clinical recommendations to minimize intra- and postoperative complications with the ultimate scope of improving the standard of clinical care and patient safety.

CBCT for Diagnostics, Treatment Planning and Monitoring of Sinus Floor Elevation Procedures

Sinus floor elevation (SFE) is a standard surgical technique used to compensate for alveolar bone resorption in the posterior maxilla. Such a surgical procedure requires radiographic imaging pre- and postoperatively for diagnosis, treatment planning, and outcome assessment. Cone beam computed tomography (CBCT) has become a well-established imaging modality in the dentomaxillofacial region. The following narrative review is aimed to provide clinicians with an overview of the role of three-dimensional (3D) CBCT imaging for diagnostics, treatment planning, and postoperative monitoring of SFE procedures. CBCT imaging prior to SFE provides surgeons with a more detailed view of the surgical site, allows for the detection of potential pathologies three-dimensionally, and helps to virtually plan the procedure more precisely while reducing patient morbidity. In addition, it serves as a useful follow-up tool for assessing sinus and bone graft changes. Meanwhile, using CBCT imaging has to be standardized and justified based on the recognized diagnostic imaging guidelines, taking into account both the technical and clinical considerations. Future studies are recommended to incorporate artificial intelligence-based solutions for automating and standardizing the diagnostic and decision-making process in the context of SFE procedures to further improve the standards of patient care.

A Combination of Platelet-Rich Fibrin and Collagen Membranes for Sinus Membrane Repair: A Case Report (Repair of Sinus Membrane Perforation)

Maxillary sinus lift surgery is applied to compensate for the reduced vertical height in the posterior maxilla to facilitate placing a dental implant of a suitable length. Pathological conditions may be accidentally discovered, which necessitate careful assessment and management to prevent the infection of the maxillofacial complex and eventually bone grafting and dental implant failure. This case report describes an approach for the management of Schneiderian membrane perforation associated with the removal of an antral pseudocyst for successful dental implant therapy. A 70-year-old healthy Caucasian male presented for implant therapy to replace a non-restorable maxillary molar. Initial examination revealed the need for a sinus lift procedure to prepare the site for implant placement. A 3D CBCT evaluation before surgery revealed an incidental finding of a pathological lesion at the surgical site. The histological analysis of a biopsy specimen retrieved during implant site preparation showed findings consistent with antral pseudocyst. The resulting perforation of the sinus membrane was treated, and an adequate period of healing was given. A thickened sinus membrane was detected upon surgical exposure for implant placement. The novel technique illustrated could result in a fibrotic repaired sinus membrane and help shorten the time required for dental implant treatment.

Preoperative HbA1c and Blood Glucose Measurements in Diabetes Mellitus before Oral Surgery and Implantology Treatments

Diabetes mellitus has become a worldwide epidemic and is frequently accompanied by a number of complications proportional to the duration of hyperglycemia. The aim of this narrative review is to assess the most up-to-date guidelines on DM provided by both diabetes and dental associations. Furthermore, to gather evidence on the uni/bidirectional relationships of elevated HbA1c levels on dental surgery, implantology, bone augmentation, and periodontology and to demonstrate the importance of measuring HbA1c levels before invasive dental treatments. HbA1c and blood glucose measurements are a minimally invasive method for preventing complications in diabetes mellitus. The authors conducted a literature review to determine which oral conditions are affected by diabetes mellitus. MEDLINE served as a source with the use of a specific search key. Regarding oral complications of diabetes, prevention is the most vital factor. With this publication, we hope to assist physicians and dentists to make prompt diagnoses and to help in recognizing various oral manifestations of diabetes and follow the existing guidelines.

Biomechanical evaluation of custom-made short implants with wing retention applied in severe atrophic maxillary posterior region restoration: A three-dimensional finite element analysis

Severe bone atrophy in the maxillary posterior region poses a big challenge to implant restoration. Digitally designed and customized short implants with wing retention provide a safer and minimally invasive implant restoration scheme in such circumstances. Small titanium wings are integrated with the short implant supporting the prosthesis. Using digital designing and processing technology, the wings fixed by titanium screws can be flexibly designed, providing the main fixation. The design of the wings will influence the stress distribution and implant stability. This study analyzes the position, structure, and spread area of the wings fixture scientifically by means of three-dimensional finite element analysis. The design of the wings is set to linear, triangular, and planar styles. Under the simulated vertical and oblique occlusal forces, the implant displacement and stress between the implant and the bone surface are analyzed at different bone heights of 1 mm, 2 mm, and 3 mm. The finite element results show that the planar form can better disperse the stress. By adjusting the cusp slope to reduce the influence of lateral force, short implants with planar wing fixtures can be used safely even if the residual bone height is only 1 mm. The results of the study provide a scientific basis for the clinical application of this new customized implant.

Association between smoking and Schneiderian membrane perforation during maxillary sinus floor augmentation: A systematic review and meta-analysis

OBJECTIVE

To estimate the association between smoking and Schneiderian membrane perforation in sinus floor augmentation.

MATERIALS AND METHODS

Searches were conducted in PubMed, Web of Science, Embase, and Cochrane Library. Data were extracted by two authors independently. The inclusion criteria were the (1) age of patients >18, (2) the number of participants >10, and (3) smoking and the patients of Schneiderian membrane perforation were accurately recorded. The risk of bias was assessed by the Newcastle-Ottawa scale (NOS). Statistics analyses were conducted using Reman5.4.1 and Stata (15.0). The association of Schneiderian membrane perforation with smoking habits during maxillary sinus floor elevation was expressed as odds ratios (ORs) with a 95% confidence interval (95% CIs). And the I2 statistic was used to estimate statistical heterogeneity. The funnel plot and Egger's tests were used to evaluate the reliability and stability of the results.

RESULTS

Of 1463 articles screened, nine studies were included in our systematic review, and eight were synthesized for meta-analysis. Eight were retrospective observational studies and one was a clinical trial, with a total of 1424 patients included. The nine studies were proved as high quality according to the NOS. There was no significant publication bias in the studies (p = 0.827). A random-effects model was used because of differences in the adopted methodologies (p = 0.39, I2  = 5%). During maxillary sinus augmentation, smoking and Schneiderian membrane perforation were associated (odds ratios, 1.58 [95% CI, 1.10-2.25]).

CONCLUSION

Smoking increased the risk of membrane perforation in maxillary sinus floor augmentation. Our evaluation was limited by the poor reporting of the number of cigarettes smoked per day (PROSPERO number was CRD42022306570).

Changes in sinus mucosal thickening in the course of tooth extraction and lateral sinus augmentation with surgical drainage: A cone-beam computed tomographic study

OBJECTIVES

The objective of the study was to evaluate the radiographic changes in sinus mucosal thickness (SMT) in patients with mucosal thickening of odontogenic origin after maxillary molar extraction and lateral sinus augmentation with simultaneous surgical drainage and implant placement.

MATERIALS AND METHODS

Forty-six patients were included in this study. The changes in SMT were evaluated using cone-beam computed tomography images produced at four time points: before extraction (T0), before surgery (T1), immediately after surgery (T2), and after prosthesis delivery (T3), and statistical differences between time points were analyzed. The changes in SMT and augmented bone height (ABH) regarding the reason of extraction, smoking, ostial patency, and the presence of postoperative sinusitis were also evaluated.

RESULTS

Over time points, SMT gradually decreased (T0: 19.44 ± 9.22 mm, T1: 15.10 ± 8.89 mm, T2: 8.42 ± 6.01 mm, and T3: 4.16 ± 4.91 mm) (p < .05). Five out of 6 patients with ostial obstruction at T1 presented ostial patency at T3. Two patients developed postoperative sinusitis but recovered with medication. Ostial patency at T1, SMT at T1, and reason of extraction did not statistically significantly influence SMT at T3. SMT at T1 had no statistically significant impact on ABH change between T2 and T3.

CONCLUSION

Sinus mucosal thickness was gradually reduced by extraction of compromised teeth and drainage during lateral sinus augmentation. The drainage contributed more to the reduction in SMT.

Evaluation of alveolar antral anastomosis in south Indian population using cone beam computed tomography: a prospective study

OBJECTIVES

The posterior superior alveolar artery (PSAA) and the infraorbital artery (IOA), both of which are ultimate branches of the maxillary artery, are connected by a horizontal anastomosis. PSAA anastomoses intraosseously and extraosseously with IOA. Profuse bleeding from the lateral wall while performing the direct sinus augmentation is a significant intraoperative complication.Thus the present study focused to assess the location of an alveolar antral anastomosis (AAA) in relation to the crest of the alveolar bone using cone beam computed tomography (CBCT).

METHODS

A total of 200 CBCT scans of patients who were indicated for implant surgery were chosen and assessed. Group 1 includes 100 dentate patients and Group 2 includes 100 partially edentulous patients. The location of anastomosis along the lateral wall of the maxillary sinus was evaluated in association with alveolar bone height with respect to three posterior maxillary teeth: first premolar, second premolar, and first molar.

RESULTS

The mean distance for P1, P2, and M1 was 21.94 ± 1.02 mm, 19.41 ± 0.40 mm, and 17.36 ± 0.51 mm, respectively, in the dentate group, whereas in the edentulous group, it was 20.07 ± 0.46 mm, 18.95 ± 0.32 mm, and 16.08 ± 0.16 mm. In 80% of participants, the distance of an AAA from the alveolar crest was between 16 and 23 mm, whereas in 12% of the participants the distance of an AAA from the alveolar crest was less than 16 mm.

CONCLUSION

The present study concludes that the first premolar region is safe for preparing the lateral window but for the second premolar and first molar additional care should be taken prior to surgery.

Application of a Titanium Screw for the Hemorrhage from the Bone Channel during the Lateral Window Technique: A Technical Note

Pulsatile and profuse hemorrhage occurred in the lateral window technique for implant placement. The surgery was performed in the dental clinic under local anesthesia. The posterior superior alveolar artery was suspected to be the main feeder. Ordinary methods for hemostasis, such as vasoconstrictor-soaked gauze compression, electrocautery hemostasis, absorbable hemostat packing, and bone wax application, were tried. However, strong pulsatile bleeding could not be controlled at all. Complete hemostasis was hardly expected. The idea came up when the titanium screws came into sight. The sterilized screw was always stocked for bone grafting. After visualizing the bleeding point clearly by suction, and the screw was inserted into the bone channel. The bleeding was completely stopped immediately. It may not be a novel method, but is certainly a reliable application of the screw, which is fundamentally the same as arterial catheter embolization.

Influence of the contact area of the sub-antral space with sinus bone and the Schneiderian membrane on osteogenesis in lateral window sinus elevation surgery: a prospective experiment

BACKGROUND

Osteogenesis of lateral window sinus elevation surgery is the key to placement of the subsequent implant, excessive collapse of the sub-antral space may adversely affect long-term stability of implants. At present, few studies focus on the influence of the contact area of the sub-antral space on osteogenesis. This study evaluated whether the change in the contact area of the sub-antral space with maxillary sinus bone and the Schneiderian membrane can affect osteogenesis.

METHODS

Cone beam computed tomography (CBCT) images were collected of patients requiring maxillary sinus floor elevation (residual bone height < 6 mm) for standard-length implant placement before surgery, after surgery, and at 6-month follow-up visits. The postoperative sub-antral space volume (V₁) and surface area (S₁), and the remaining volume after six months of healing (V₂) were measured. Then, the contact area of sub-antral space with maxillary sinus bone (S_bc) and the Schneiderian membrane (S_mc), the absorbed volume during healing (V_a), and the percentage of remaining volume (V₂%) and absorbed volume (V_a%) were calculated. The correlation between anatomical parameters was analyzed using multiple linear regression.

RESULTS

A total of 62 maxillary sinuses from 56 patients were augmented, of which 57 were considered for the final analysis (5 withdrew due to perforation). Multiple linear regression results demonstrated that S_bc was significantly positively correlated with V_a (β coefficient = 0.141, p < 0.01) without correlation between S_mc and V_a (β coefficient =  - 0.046, p = 0.470). There was a positive correlation between S_bc and V₂% (β coefficient = 2.269, p < 0.05).

CONCLUSIONS

This study confirmed that the size of the S_bc in lateral window sinus elevation surgery affected osteogenesis after six months of healing. Clinicians should assess the sinus contour type preoperatively, then consider whether it is necessary to expand the range of the Schneiderian membrane elevation to avoid excessive collapse of the sub-antral space.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR), ChiCTR2200057924. Registered 22 March 2022-Retrospectively registered.

Healing Patterns of Non-Collagenated Bovine and Collagenated Porcine Xenografts Used for Sinus Floor Elevation: A Histological Study in Rabbits

Objective: To compare healing of collagenated and non-collagenated xenografts used for maxillary sinus floor elevation. Materials and Methods: Two different xenografts were used: deproteinized bovine bone (DBBM group) and collagenated corticocancellous porcine bone (collagenated group). Healing was studied after 2, 4, and 8 weeks. The loss of dimensions of the elevated area and the percentages of new bone, xenograft remnants, osteoclastic zones, vessels, inflammatory infiltrates, and soft tissues were analyzed. Three regions were evaluated: close to the bone walls (bone wall region), subjacent the sinus mucosa (submucosa region), and the center of the elevated area (middle region). The primary variables were the percentage of new bone and xenograft remnants. Results: Between 2 and 8 weeks, the elevated areas showed a reduction of 16.3% and 52.2% in the DBBM and collagenated groups, respectively (p < 0.01 between the two areas after 8 weeks). After 8 weeks, the highest content of new bone was observed in the bone wall region, which was higher in the collagenated group than in the DBBM group (41.6% and 28.6%, respectively; p < 0.01). A similar quantity of new bone was found between the two groups in other regions. A higher percentage of vessels in all regions evaluated (p < 0.01) and soft tissue in the sub-mucosa region (p < 0.05) was found in the collagenated group than in the DBBM group. Conclusions: The present study showed that both xenografts allowed new bone formation. In comparison with the non-collagenated xenograft, the collagenated xenograft underwent higher resorption, resulting in greater shrinkage of the elevated space after sinus lifting and a higher content of new bone in the regions close to the bone walls. Clinical relevance: In this study, the region adjacent to the bone wall showed the highest new bone content. This region resembles the base of the sinus, closest to the sinus floor and walls, and is the most important region from a clinical point of view because it is where the implant will be installed. Residues of the biomaterial remained after 8 weeks of healing. Other reports have shown that these biomaterial residues may interfere with the integration of implants.

Use of a Lateral Sinus Bony Window as an Intraoral Donor Site for Guided Bone Regeneration in Wide Post-Extraction Defects

Maxillary sinus augmentation (MSA) and guided bone regeneration (GBR) have shown successful clinical, radiological, and histological outcomes for implant-related bone reconstruction and have been used to augment bony defects of various shapes and sizes. This study demonstrated that the lateral sinus bony window obtained during MSA can be used as an autogenous block bone graft for the augmentation of wide post-extraction defects. During the uncovering procedure performed 6 months after surgery, the grafted lateral bony window was well integrated with the adjacent native bone, and complete bone filling was observed in all bony defects around the implants. All of the implants survived. Within the limitations of this study, autogenous block bone obtained from lateral window sites can be used as novel donors for the resolution of wide bony defects around implants.

Complications of sinus floor elevation procedure and management strategies: A systematic review

AIM

This systematic review aimed to investigates the types and incidences of complications following sinus floor elevations (SFE) along with their prevention and management strategies.

MATERIALS AND METHODS

Electronic database and hand search were conducted to screen the literature published from January 1960 to June 2021. The selected studies had to report well-described SFE techniques, complications during, and post-SFE. Data extraction included types of SFE techniques, complications, and their treatment strategies.

RESULTS

A total of 74 studies with 4411 SFE procedures met the inclusion criteria. Different SFE techniques demonstrated varying patterns for both complications and complication rates. Postoperative pain, swelling, and edema were widely reported. The most common complications that required intervention following Lateral SFE (LSFE) were sinus membrane perforation (SMP), wound dehiscence, graft exposure and failure, and sinusitis. LSFE had more SMPs and sinusitis cases compared with a transcrestal SFE (TSFE). The presence of benign paroxysmal positional vertigo following TSFE was significant in certain selected studies.

CONCLUSION

Given the inherent limitations, this systematic review showed distinct features of complications in SFE using varying techniques. Treatment planning for these procedures should incorporate strategies to avoid complication occurrence.

The use of corticosteroids in the lateral sinus augmentation surgical procedure: A systematic review and meta-analysis

BACKGROUND

The lateral maxillary sinus augmentation (MSA) procedure has good predictability in terms of the success of bone regeneration with a low incidence of postoperative infections, estimated between 2% and 5.6%. Although the use of antibiotics is an established and standardized prophylactic measure for MSA procedures, the addition of corticosteroids still varies among clinician preference and clinical judgment.

PURPOSE

The aim of this systematic review was to identify whether the administration of corticosteroids during the MSA surgical procedure affects postoperative symptoms including swelling, pain, and infection rate.

MATERIALS AND METHODS

A literature search through PubMed, EMBASE, Ovid MEDLINE, and Web of Science indices, according to PICO criteria, was conducted to identify whether MSA peri-operative use of corticosteroids reduces the incidence of complications and patient morbidity. A single arm meta-analysis was performed due to the lack of randomized controlled trials (RCTs) comparing groups treated with or without peri-operative corticosteroids. The intracluster correlation co-efficient (ICC) and design effect were calculated to adjust for the clustering design.

RESULTS

In the 37 studies included, a total of 1599 patients (378 Cort, 1221 No-Cort) were analyzed. Before and after taking account of clustering, there was statistically significant effect of corticosteroids on swelling, pain, wound dehiscence, trismus, and hematoma. The complication rates postoperatively were comparable between the two study groups, however slight differences existed in the incidence of active suppuration (1.7% [95% CI 0.7-3.9] Cort vs. 3.2% [2.2-4.5] No-Cort), wound dehiscence (3.9% [1.3-11.2] Cort vs. 2.1% [1.0-4.1] No-Cort) and trismus (2.7% [0.8-8.4] Cort vs. 1.4% [0.8-2.5] No-Cort).

CONCLUSIONS

Although the event rate of the 1-to-2-week postoperative complications did not differ between the two groups, the lack of conclusive data and research comparing peri-operative corticosteroid use makes it impossible to draw definitive conclusions and more evidence and studies designed for this specific purpose are needed.

Short and Ultra-Short Implants, in Association with Simultaneous Internal Sinus Lift in the Atrophic Posterior Maxilla: A Five-Year Retrospective Study

Recent short-term studies suggested the use of short and ultra-short implants in association with a modified osteotome sinus floor elevation (internal sinus lift) technique for the treatment of edentulous resorbed posterior maxilla. The aim of this retrospective study was to investigate this hypothesis in locking-taper implants with a mid-term follow-up of 5 years. Overall, 155 implants (32, 100, and 23 of, respectively, 5.0 mm, 6.0 mm, and 8.0 mm length) were positioned in the atrophic upper maxilla of 79 patients, and 151 implants were loaded with single crowns. Overall implant survival after 5 years was 94.84%. Implant survival for each length group was 93.75%, 94%, and 100% for 5.0, 6.0, and 8.0 mm length, respectively. Preoperative residual crestal bone height of 4.45 (1.3) mm increased to 9.25 (2.13) mm after implant placement and settled at 6.35 (1.73) mm after loading and at 5.25 (1.68) mm at follow-up. Elevation of the Schneiderian membrane was 4.8 (2.46) mm after implant placement, 3.06 (1.3) mm after loading, and 1.46 (1.06) mm at follow-up. Mean variations of peri-implant crestal bone loss and first bone-to-implant contact point were, respectively, -0.36 (1.3) mm and -0.62 (1.15) mm. It can be confirmed that internal sinus lift procedure revealed stable bone gain and negligible resorption at mid-term follow-up for atrophic upper crests with reduced height.

Application of an assembled surgical guide for lateral approach sinus augmentation and sinus septum management: A technical note

The presence of maxillary septa may render sinus augmentation more challenging particularly when encountered at the ideal implant position. This article demonstrated a novel technique for lateral access sinus augmentation using an assembled surgical guide to achieve proper lateral window outline, precise septum identification and osteotomy, and secure membrane detachment. This technique increases the predictability and efficiency of the procedure while reducing the risk of complications.

Simultaneous Implant Placement and Sinus Lift Using Leukocyte-Platelet Rich Fibrin: A Retrospective 40-Month Study

ABSTRACT

The aim of this study was to report the 40-month clinical radiographical outcomes of maxillary sinus floor augmentation using leukocyte-platelet rich fibrin (L-PRF) as a single graft in combination with immediately placed implants. Twenty partially edentulous individuals with missing teeth in the region associated to maxillary sinus were included in this retrospective study. A lateral sinus floor elevation was performed considering a complete wear of the bone wall of the maxillary sinus and immediately placing the implant and filled the maxillary sinus with L-PRF clots as a single graft. After 5 months, all the implants received single screwed implant-supported prostheses. Subsequent evaluation was every 4 months assessing the success rate and biological complications. Two maxillary sinus membrane were perforated and covered with L-PRF clots. The mean bone height gain was 62.6%, observing a 100% of success and that in all the cases achieved at least the implant height. In conclusion, the use of platelet-rich fibrin clot as a single graft biomaterial during the maxillary sinus lift procedure combined with immediate implant placement may be a reliable clinical alternative, even to repair the sinus membrane.

The Relation between Morphology of Maxillary Sinus after Augmentation in Three Classification Methods and Residual Bone Height: A Retrospective Study

Maxillary sinus augmentation is critical to oral implantology, particularly in some cases. The morphology of the sinus floor reflects the lifting effect to a certain extent; however, there has been limited research on the morphology after sinus augmentation. The present study aims to investigate the relationship between residual bone height (RBH) and the morphology of the sinus floor and determine whether a correlation exists between the different evaluation classifications. Maxillary sinus floor augmentation procedures were performed in 56 patients and 68 teeth using the sinus crest approach (SCA). Imaging results obtained after one year of sinus augmentation were analyzed and simultaneously classified along the coronal plane, the sagittal plane, and the biplane (coronal-sagittal). The higher the RBH, the closer the result tends to be to A, A', or type 1 (more satisfactory). There was a significant correlation between the three different evaluation classifications (p < 0.05). The morphology of perforation cases was involved in types C, D, C', and D'. A more satisfactory post-lifting morphology (tent type and flat type) is probably related to an optimal preoperative bone height, and an unsatisfactory post-lifting morphology is related to a low preoperative sinus floor height. The sagittal plane evaluation correlates with the coronal plane and biplane evaluation and is thus more recommended.

Influence of the Use of a Collagen Membrane Placed on the Bone Window after Sinus Floor Augmentation-An Experimental Study in Rabbits

BACKGROUND

We studied the influence on healing of a resorbable membrane covering the osteotomy site after maxillary sinus grafting, evaluated in different regions of the augmented area.

METHODS

Maxillary sinus augmentation was performed in 24 New Zealand rabbits. Osteotomy, 4 × 6 mm, were performed bilaterally. A collagenated cortico-cancellous porcine bone was used to fill the elevated region. A collagen membrane was randomly placed over the osteotomy site on one side (MG), and the other side was left uncovered (NMG). The animals were euthanized after 2, 4, and 8 weeks; and histomorphometric analysis was performed in eight different regions.

RESULTS

New bone percentages were similar in both groups. There were no statistically significant differences. In MG, the overall percentages were 15.6 ± 7.3%, 22.9 ± 6.1%, and 24.9 ± 12.0% after 2, 4, and 8 weeks, respectively. In NMG, the percentages were 11.2 ± 4.5%, 24.1 ± 5.7%, and 24.5 ± 15.7%, respectively. The proportions of new bone in the various regions after 8 weeks were 31 ± 8.9% and 29.9 ± 9.1% in the bone walls region, 25 ± 10.1% and 32.8 ± 9.1% in the submucosa region, 22.6 ± 21.6% and 10.9 ± 11.5 in the middle region, 17.3 ± 14% and 13.4 ± 9.8% in the close-to-window region, and 21.8 ± 11.6%, 19.1 ± 6.4% in the osteotomy region-for MG and NMG, respectively.

CONCLUSIONS

In both groups the greatest amounts of bone formation occurred near to the pre-existing bone walls, followed by the sub-mucosa region. The smallest amounts were found in the close-to-window region, followed by the central region. The placement of a collagen membrane to cover the osteotomy site did not influence the amount of new bone formation after sinus grafting.

Risk factors for sinus membrane perforation during lateral window maxillary sinus floor elevation surgery: A retrospective study

PURPOSE

To analyze the sinus membrane perforation (SMP) rate and its potential risk factors during lateral window maxillary sinus floor elevation (LSFE).

MATERIALS AND METHODS

For patients with LSFEs at Department of Implantology, Stomatology Hospital, School of Medicine, Zhejiang Universitiy during January 2014 to December 2020, patient-related risk factors (age/sex/smoking habit), surgery-related risk factors (operator experiment/number of tooth units/technique of osteotomy/surgical approach), and maxillary sinus-related risk factors (residual bone height/sinus membrane thickness/lateral wall thickness/maxillary sinus contours/presence of septa/blood vessels at the lateral maxillary sinus wall) were compared between perforated and nonperforated sites and were evaluated for their influence affecting SMP.

RESULTS

The study sample comprised 278 LSFE procedures in 278 patients; a total of 47 LSFE procedures (16.91%) presented SMP. Four significant factors were identified: smoking habit (p < 0.001), thin (≤1.5 mm) sinus membrane (p = 0.027), maxillary sinus contours (p < 0.001), and presence of septa (p = 0.001). The SMP rate of irregular, narrow tapered, and tapering sinus contours was significantly higher than that of ovoid and square one (p < 0.05).

CONCLUSION

In general, smoking habit, thin sinus membrane, irregular, narrow tapered, and tapering sinus contours, and presence of septa may increase the risk of SMP during LSFE.

A Replicable and Reproducible Digital Method for Quantifying Maxillary Sinus Airway Changes after Sinus Lifts Using the Lateral Window Approach Technique-A Retrospective Study

In the present retrospective study, we aimed to assess the replicability and reproducibility of a novel digital measurement technique for analyzing the volumes of the left and right maxillary sinuses and the nasal and maxillary sinus airway complex after a sinus lift procedure using the lateral window approach, to provide an accurate measurement technique for easily applying in clinical practice and to allow pre-operative assessment of maxillary sinus lift surgery, avoiding complications and making surgery more predictable. Material and Methods: Thirty patients with partially edentulous posterior maxilla were selected and submitted to bilateral sinus lift using the lateral window approach technique, with grafting materials selected and submitted to cone beam computed tomography (CBCT) scans, both pre- and postoperatively. Then, datasets were uploaded to therapeutic digital planning software to measure the volume of the right and left maxillary sinuses and the nasal and maxillary sinus airway complex. Gage R&R statistical analysis was performed to assess the replicability and reproducibility of the digital measurement technique. Results: The variability attributable to the novel digital measurement technique was 3.4% for replicability and 3.4% for reproducibility of the total variability of the samples. Conclusion: The novel digital method proposed is a replicable and reproducible technique for analyzing the volume of the right and left maxillary sinuses and the nasal and maxillary sinus airway complex after a sinus lift using the lateral window approach technique, allowing an accurate pre-operative assessment of maxillary sinus lift surgery, avoiding complications and making surgery more predictable.

Management of sinus graft infection-a systematic review

Sinus graft infections are rare but serious complications, as they are associated with significant morbidity and sinus graft loss. The aim of this study was to systematically review the management of sinus graft infection in order to define which protocols should be implemented. The terms searched in each database were "sinus graft infection management", "maxillary sinus lift infection", "maxillary sinus graft infection", "maxillary sinus elevation infection", and "maxillary sinus augmentation infection". The management of the sinus graft infection was assessed. The outcomes evaluated were maxillary sinus health and dental implantation results. The initial search yielded 1190 results. Eighteen articles were included, reporting a total of 3319 patients and 217 sinus graft infections. Drainage was performed with an intraoral approach in 13 studies, an endoscopic approach in two studies, and a combined approach in three studies. In every study, a disease-free sinus was finally obtained in all patients, but the outcomes of the graft and the dental implant were more varied. It is not possible to define the best treatment protocol for sinus graft infections based on the published data, since the level of evidence is poor. Management is very heterogeneous. This review highlights the necessity of surgical treatment associated with antibiotic therapy.

Argon Bioactivation of Implants Installed Simultaneously to Maxillary Sinus Lifting without Graft. An Experimental Study in Rabbits

Background: The treatment of the surface of titanium implants with argon plasma improved its hydrophilicity and cell adhesion, resulting in higher bone apposition on implant and graft surfaces. The spontaneous perforation over time of the sinus mucosa after sinus augmentation has been documented in experimental studies at both implants and graft particles. The aim of the present study was to evaluate the influence of plasma argon treatment of the implant surface on bone apposition and on the rate of sinus mucosa perforations. Methods: A sinus lifting procedure was performed bilaterally in sixteen rabbits, and implants, either treated with argon plasma or left without treatment (control), were placed simultaneously without grafts. After 8 weeks, histological analyses were carried out. Results: A collapse of the sinus mucosa was observed at all implants. Twenty-four out of thirty-two implants presented sinus mucosa perforations at the apex. Several perforations were also found at the threads. Thinned mucosa sites (width < 40 µm) were found around almost all implants. About 2.6–2.9 mm of the apical regions of the implant did not present signs of osseointegration and about 1.3 mm were exposed to the sinus cavity. No statistically significant differences were found between plasma and control sites. Conclusions: In conclusion, the sinus mucosa was damaged and perforated by direct contact with treated and non-treated implant surfaces. The treatment of the implant surface with argon plasma did not affect the outcomes.

Etiology and Management of Complications Associated with Sinus Augmentation Procedures

Sinus floor elevation is a predictable procedure for vertical bone augmentation in the atrophic posterior maxilla. As with most surgical procedures, complications can be encountered during sinus floor elevation/augmentation. A clinician should have a thorough knowledge of factors that can lead to complications and possible ways to manage. Presurgical evaluation of the sinus is a prerequisite in identifying the concomitant presence of systemic disease and maxillary sinus disease that may lead to postoperative complications. Despite the best efforts, one may encounter adverse events. Complications can broadly be divided into intraoperative, acute, and chronic complications based on the timing of its occurrence. The most commonly encountered complications include membrane perforation and excessive bleeding. Evaluation of anatomic deviations and sound surgical skill is required to reduce intraoperative complications. Prevention is better than cure. It is always better to know how and when a complication might occur so that the clinician might take the necessary steps to avoid it. This article reviews the management of most commonly encountered complications and the best possible ways to manage them.

Repairing maxillary sinus membrane perforations, iatrogenic or intentional: Two case reports

INTRODUCTION

Maxillary sinus augmentation is a common and predictable procedure utilized to gain vertical alveolar bone height to allow for successful placement of dental implants in the deficient posterior maxilla. The surgical techniques, however, may be associated with intraoperative complications, the most common of which is Schneiderian membrane perforation and, less commonly, bleeding and the loss of an implant into the sinus cavity.

CASE PRESENTATION

In the current report, we present two cases with unique complications. A large perforation which was discovered after the graft material had been placed was successfully managed by carefully removing the graft material from both sides of the perforation and sealing the perforation with a resorbable membrane and a tack fixation. The second case involved a patient who presented with an implant that had migrated into the sinus during an unsuccessful transcrestal sinus lift. The case was successfully treated by locating and removing the implant through an intentional membrane perforation, repairing the perforation, and placing a new implant with simultaneous grafting.

CONCLUSION

Management and repair of maxillary sinus membrane perforations that are either intentionally or iatrogenically created can be predictable procedures with favorable outcomes if thoughtful evaluation and treatment are provided. Managing such complications at the time of occurrence avoids unnecessary additional surgical procedures that might prove to be even more complicated.

Advantages of Porcine Xenograft over Autograft in Sinus Lift: A Randomised Clinical Trial

This study aimed to compare the performance of intra-oral autologous bone grafts versus porcine xenografts in a two-step lateral window sinus lift. This split-mouth randomised controlled trial sequentially enrolled 12 patients with a 6-month follow-up. For each patient, a simultaneous randomised bilateral maxillary sinus lift was performed and filled with autologous bone from the mandible (control) or a porcine xenograft (test). A bone biopsy sample was collected during the implant placement for histological and histomorphometric analysis. CT scans were performed at the beginning and at the end of the trial to assess radiological evolution. A comparison of initial and six-month CT scans indicated statistically significant increases in bone level for both materials (7.8 ± 2.4 mm for autologous and 8.7 ± 2.2 mm for xenograft, p < 0.05), and there were no significant differences between the performance of the two materials over time (p = 0.26). The histological analysis showed various stages of the remodelling process and no cells or other signs of inflammation or infection were visible in both groups. The porcine xenografts presented similar results for the studied variables when compared to autologous bone, being a reasonable alternative for a sinus lift.

Position of posterior superior alveolar artery in relation to the maxillary sinus using cone beam computed tomography in Indian sub-population

Purpose: To assess the location of posterior superior alveolar artery (PSAA) using CBCT in relevance to sinus lift procedure for implant placement. Patients and Methods: A retrospective study was conducted using the CBCT data of 500 patients (n = 500). Linear measurements were carried out to localize the medio-lateral and vertical position of posterior superior alveolar artery in postero-lateral wall of maxillary sinus and its proximity to the floor of maxillary sinus using CS 3D imaging 3.7.0 software program. The relative position of PSAA was determined as; (a) intra-osseous, (b) below the membrane and (c) outer-cortex of lateral sinus wall. The location of PSAA was assessed in molar region bilaterally by using following radiographic measurement; (1) distance between the lower border of posterior superior alveolar artery and alveolar crest, (2) height from the floor of maxillary sinus to alveolar crest and (3) distance from the posterior superior alveolar artery to medial wall of maxillary sinus. Results: The prevalence of the artery was observed in 99.4% of the sinuses and was mostly intraosseous (84.2%).The mean distance between the lower border of the artery and alveolar crest is significantly higher in males compared to females (P < 0.01). The distribution of artery location did not differ significantly across various age groups (P > 0.05). Discussion/Conclusion: The most common variant of PSAA was identified in the intra-osseous region and the mean distance of the vessel to crest of the residual ridge differs significantly with gender and not with age.

Different Treatment Modalities Using Dental Implants in the Posterior Maxilla: A Finite Element Analysis

The objective of this study was to compare the biomechanical behavior of peri-implant bone tissue and prosthetic components in two modalities of treatment for posterior region of the maxilla, using short implants or standard-length implants associated with bone graft in the maxillary sinus. Four 3D models of a crown supported by an implant fixed in the posterior maxilla were constructed. The type of implant: short implant (S) or standard-length implant with the presence of sinus graft (L) and type of crown retention: cemented (C) or screwed (S) were the study factors. The models were divided into SC- cemented crown on a short implant; SS- screwed crown on the short implant; LC- cemented crown on a standard-length implant after bone graft in the maxillary sinus and LS- crown screwed on a standard-length implant after bone graft in the maxillary sinus. An axial occlusal loading of 300 N was applied, divided into five points (60N each) corresponding to occlusal contact. The following analysis criteria were observed: Shear Stress, Maximum and Minimum Main Stress for bone tissue and von Mises Stress for the implant and prosthetic components. The use of standard-length implants reduced the shear stress in the cortical bone by 35.75% and the medullary bone by 51% when compared to short implants. The length of the implant did not affect the stress concentration in the crown, and the cement layer acted by reducing the stresses in the ceramic veneer and framework by 42%. Standard-implants associated with cemented crowns showed better biomechanical behavior.

Different techniques in transalveolar maxillary sinus elevation: A literature review

Dental implant treatment in the posterior maxilla encounters bone quality and quantity problems. Sinus elevation is a predictable technique to overcome height deficiency in this area. Transalveolar sinus elevation is a technique that is less invasive and less time-consuming, first introduced for ridges with at least 5 mm of bone height. Many modifications and innovative equipment have been introduced for this technique. This review aimed to explain the modifications of this technique with their indications and benefits.

An exhaustive search in PubMed Central and Scopus electronic databases was performed until December 2020. Articles were selected that introduced new techniques for the transalveolar maxillary sinus approach that had clinical cases with full texts available in the English language. Finally, twenty-six articles were included. The data were categorized and discussed in five groups, including expansion-based techniques, drill-based techniques, hydraulic pressure techniques, piezoelectric surgery, and balloon techniques.

The operator’s choice for transalveolar approach techniques for sinus floor elevation can be based on the clinician’s skill, bone volume, and access to equipment. If possible, a technique with simultaneous implant placement should be preferred.

Factors influencing the sinus membrane thickness in edentulous regions: a cone-beam computed tomography study

BACKGROUND

During implant treatment in the maxillary molar area, maxillary sinus floor augmentation is often performed to ameliorate the reduced alveolar bone height attributable to bone remodeling and pneumatization-induced expansion of the maxillary sinus. However, this augmentation may cause complications such as misplaced implants, artery damage, and maxillary sinus mucosal perforation; infections like maxillary sinusitis; and postsurgical complications such as bone graft leakage and postoperative nasal hemorrhaging. To reduce the complications during maxillary sinus floor augmentation and postoperative infections, we performed retrospective investigations of various systemic and local factors that influence pre-operative sinus mucosal thickness (SMT) by using cone-beam computed tomography (CBCT). Subjects included patients who underwent maxillary sinus floor augmentation in an edentulous maxillary molar area with a lateral approach. Pre-operative SMT, existing bone mass, and nasal septum deviation were measured using CBCT images. Relationships between SMT and the following influencing factors were investigated: (1) age, (2) sex, (3) systemic disease, (4) smoking, (5) period after tooth extraction, (6) reason for tooth extraction, (7) residual alveolar bone height (RBH), (8) sinus septa, and (9) nasal septum deviation. Correlations were also investigated for age and RBH (p < 0.05).

RESULTS

We assessed 35 patients (40 sinuses; 11 male, 24 female). The average patient age was 58.90 ± 9.0 years (males, 57.9 ± 7.7 years; females, 59.9 ± 9.4 years; age range, 41-79 years). The average SMT was 1.09 ± 1.30 mm, incidence of SMT > 2 mm was 25.0%, incidence of SMT < 0.8 mm was 50.0%, and the average RBH was 2.14 ± 1.02 mm. The factors that influenced SMT included sex (p = 0.0078), period after tooth extraction (p = 0.0075), reason for tooth extraction (p = 0.020), sinus septa (p = 0.0076), and nasal septum deviation (p = 0.038).

CONCLUSIONS

Factors associated with higher SMT included male sex, interval following tooth extraction < 6 months, periapical lesions, sinus septa, and nasal septum deviation. Factors associated with SMT > 2 mm were sex and reason for tooth extraction, while factors associated with SMT < 0.8 mm were time following tooth extraction and nasal septum deviation. Despite the limitations of this study, these preoperative evaluations may be of utmost importance for safely conducting maxillary sinus floor augmentation.

Implant Placement Following Crestal Sinus Lift with Sequential Drills and Osteotomes: Five Years after Final Loading Results from a Retrospective Study

The aim of this retrospective study was to clinically evaluate the five-year outcomes of implants placed following a combined approach to the sinus, consisting of sequential drills and osteotomes. Medical records of patients with implants placed in combination with crestal sinus lift using sequential drills and osteotomes, with a residual alveolar bone crest between 4 to 8 mm, and a follow-up of at least five years after final loading, were evaluated. Outcomes were implant and prosthetic survival and success rates, any complication, and marginal bone loss. Data from 96 patients (53 women and 43 men; mean age 54.7 years; range 23-79 years) were collected. A total of 105 single implants were analyzed. After five years of function, two implants were lost and two prostheses failed. No major biological or prosthetic complications occurred. At the five-year examination, the marginal bone loss was 1.24 ± 0.28 mm. Within the limitations of this retrospective study it can be concluded that implants placed following a combined approach to the sinus consisting of sequential drills and osteotomes seem to be a viable option for the treatment of posterior atrophic edentulous maxilla.