How to avoid intraoperative and postoperative complications in maxillary sinus elevation

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.

Radiographic outcomes of lateral sinus floor elevation at sites without perforations and sites with perforations managed with a resorbable membrane: A retrospective study

AIM

To evaluate the radiographic outcomes of lateral sinus floor elevation with simultaneous implant placement at sites without sinus membrane perforation (SMP) and sites with SMP managed with a resorbable membrane.

MATERIALS AND METHODS

One hundred and thirty-nine patients and 170 implants (56 perforation, 114 non-perforation) were included. Cone-beam computed tomography (CBCT) images were taken before surgery (T0), immediately after surgery (T1) and 6 months after surgery (T2). Post-operative augmentation parameters, including endo-sinus bone gain (ESBG) along the implant axis, mean new bone height (NBH) surrounding the implant and augmentation volume (AV), were measured at T1 and T2.

RESULTS

At T1, there were no significant differences in ESBG, NBH and AV between the two groups. At T2, although ESBG did not significantly differ between the two groups, NBH (8.50 ± 1.99 mm vs. 9.99 ± 2.52 mm, p = .039) and AV (519.37 ± 258.38 mm3 vs. 700.99 ± 346.53 mm3, p < .001) were significantly lower in the perforation group. The shrinkage of graft material from T1 to T2, including ΔESBG (p = .002), ΔNBH (p < .001) and ΔAV (p < .001), was higher in the perforation group.

CONCLUSIONS

SMP during LSFE with simultaneous implant placement is associated with greater resorption of the grafted area at a 6-month follow-up.

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.

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.

Atypical and Late-Developed Sinus Graft Complications Following Maxillary Sinus Augmentation: Successful Management with Guided Bone Regeneration

Complications that occur after maxillary sinus floor augmentation (MSA) can be divided into early and late complications. Early complication is a side effect that occurs during the MSA procedure or during the initial healing period. Usually, late complication refers to a side effect that occurs after 3 weeks of MSA. However, in the longer term, there are cases that occur during the follow-up period after the prosthesis is delivered, and most of them present with peri-implantitis. In the present two cases, sinus graft complications occurred 1-2 years after prosthesis delivery but were independent of peri-implantitis and had atypical features showing asymptomatic results. Although the route of the infection source is unclear, the lesions were presumed to be caused by slow and delayed inflammation of oral bacteria infiltrating the bone graft area of the maxillary sinus. Within the limitations of present case reports, bone defects were successfully managed with a guided bone regeneration (GBR) procedure that included thorough defect degranulation, surface decontamination of exposed implant, and regrafting. Periodic monitoring of radiographic images is required for the detection of unusual sinus graft complications in sinus-augmented sites.

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.

A Novel Approach for the Treatment of Recurrent Oroantral Fistula Occurring at an Infected Sinus Augmentation Site

Closing a recurrent oroantral fistula (OAF) that occurs at an infected sinus augmentation site is a challenge for clinicians. The recurrent OAF has a detrimental impact on bone regeneration and subsequent implant placement. This case report includes three cases in which sinus graft infection and OAF occurred after maxillary sinus augmentation (MSA). In these cases, treatments to control sinus infection were performed using an otolaryngologist; then, intraoral interventions comprising mucosal flap procedures, bone grafts, and barrier membrane applications were performed 2-5 times by oral surgeons. Nevertheless, OAF recurred persistently. The failure to stop OAF recurrence may be due to the inability to effectively block air pressure at the OAF site. Following a comprehensive debridement of the infected tissue at the previous sinus augmentation site, a pouch was created through sinus mucosal elevation. The perforated sinus mucosa at the OAF site was covered with a non-resorbable membrane in one case and with resorbable collagen membranes in the other two cases, followed by bone grafting within the pouch. Lastly, this procedure was completed by blocking the entrance of the pouch with a cortical bone shell graft and a resorbable collagen membrane. The cortical bone shell graft, obstructing the air pressure from the nasal cavity, facilitated bone formation, and, ultimately, allowed for implant placement. Within the limitations of the present case report, the application of a guided bone regeneration technique involving a cortical bone shell graft and a barrier membrane enabled the closure of the recurrent OAF and subsequent implant placement.