A hybrid technique for sinus floor elevation in the severely resorbed posterior maxilla

Sinus augmentation procedure via the lateral window technique-Reducing invasiveness and preventing complications: A narrative review

Sinus augmentation has become an integrated surgical phase in posterior maxillary implant prosthesis reconstruction. Since the residual alveolar bony height usually requires additional volume particularly at this anatomical region, sinus floor augmentation is advocated routinely. Over the years, Implant success rate is proved to be comparable to the one in the pristine bone, which is well documented in the literature. Anatomical aspects as well as surgeon skills are at most importance to achieve predictable outcome. In this narrative review, the different osteotomy techniques, the indications toward 1 or 2-stage approaches, the control of the Schneiderian membrane integrity as well as the management of intra- and post-operative complications are thoroughly discussed according the current data. In light of the excellent long-term implant success rate concurrent with the application of contemporary advanced techniques of the sinus augmentation via the lateral wall osteotomy approach, reduce invasiveness and less complication occurrences are well documented. A well-codified patient selection involving the rhinologist as an integral medical team would be significantly beneficial toward early diagnosis. In-depth knowledge of the anatomy, execution of a well standardized surgical technique, and understanding the complication etiology and their management are prerequisites for reducing patient morbidity to minimal discomfort and predictable successful outcome.

Maxillary Sinusitis Associated With Peri-implantitis at Sinus Floor Augmented Sites: Case Series

PURPOSE

The purpose of this case series was to investigate treatment outcomes of maxillary sinusitis associated with peri-implantitis at sinus floor augmented sites for a 3-year follow-up.

MATERIALS AND METHODS

Eighteen implants in 8 patients diagnosed with maxillary sinusitis associated with peri-implantitis were reviewed. Four patients were treated with implant removal and antibiotics, and 4 patients were treated with implant removal, the modified Caldwell-Luc operation (CLOP), and antibiotics. Seven patients, who had 7 survived implants, were followed up to 3 years after treatment. The characteristics between failed and survived implants were compared. Radiographic parameters of survived implants were analyzed using the Friedman test.

RESULTS

Eleven failed implants from 8 patients exhibited approximately 10-mm pocket depths and mobility at diagnosis. Seven survived implants from 7 patients exhibited no significant changes in crestal bone loss at the facial side for 3 years after the treatments. Sinus mucosal thickening was significantly reduced during the 3-year follow-up after the treatments.

CONCLUSION

The progression of peri-implantitis in sinus floor augmented sites may lead to maxillary sinusitis. To confirm the efficacy of the intraoral approaches, such as the modified CLOP, systematic clinical studies with a large sample size and a long-term follow-up should be conducted.

Report of a human autopsy case in maxillary sinuses augmented using a synthetic bone substitute: Micro-computed tomographic and histologic observations

OBJECTIVE

This study of a human autopsy case aimed to characterize the histologic and micro-computed tomographic results of maxillary sinus augmentation using a synthetic bone substitute and simultaneous implant placement at 6 years.

MATERIAL AND METHODS

This report is based on the whole-body donation of a 62-year-old male patient who died due to bladder cancer. Implants had been placed in conjunction with sinus augmentation using a mixture of biphasic calcium phosphate and autogenous bone into both maxillary sinuses 6 years prior to the body donation. The maxillary sinus areas containing implants were gently removed from the cadaver and scanned using high-resolution micro-computed tomography. Samples were sectioned, prepared for undecalcified histologic slides and stained with haematoxylin-eosin.

RESULTS

The augmented volume was observed up to the apex of the implants, which were successfully osseointegrated. Cross-sectional micro-computed tomographic views revealed that the bone-substitute particles were embedded in radiopaque-mineralized tissues showing a trabecular pattern around the implants. The histologic analysis revealed mature lamellar bone surrounding the remaining bone-substitute particles as well as well-organized bone marrow spaces in the augment bone area and around the dental implants.

CONCLUSION

This human autopsy study histologically confirmed the presence of successful bone formation and long-term volume stability after sinus augmentation using biphasic calcium phosphate and simultaneous implant placement.

Sinus augmentation using rhBMP-2-loaded synthetic bone substitute with simultaneous implant placement in rabbits

PURPOSE

The aim of this study was to determine the effect of recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded synthetic bone substitute on implants that were simultaneously placed with sinus augmentation in rabbits.

METHODS

In this study, a circular access window was prepared in the maxillary sinus of rabbits (n=5) for a bone graft around an implant (Ø 3×6 mm) that was simultaneously placed anterior to the window. Synthetic bone substitute loaded with rhBMP-2 was placed on one side of the sinus to form the experimental group, and saline-soaked synthetic bone substitute was placed on the other side of the sinus to form the control group. After 4 weeks, sections were obtained for analysis by micro-computed tomography and histology.

RESULTS

Volumetric analysis showed that the median amount of newly formed bone was significantly greater in the BMP group than in the control group (51.6 mm³ and 46.6 mm³, respectively; P=0.019). In the histometric analysis, the osseointegration height was also significantly greater in the BMP group at the medial surface of the implant (5.2 mm and 4.3 mm, respectively; P=0.037).

CONCLUSIONS

In conclusion, an implant simultaneously placed with sinus augmentation using rhBMP-2-loaded synthetic bone substitute can be successfully osseointegrated, even when only a limited bone height is available during the early stage of healing.

Tenting effect of the elevated sinus membrane over an implant with adjunctive use of a hydroxyapatite-powdered collagen membrane in rabbits

PURPOSE

The aim of this study was to determine the de novo bone formation beneath the Schneiderian membrane supported by an implant and with the adjunctive use of a hydroxyapatite-powdered collagen (HAC) membrane without bone grafting in rabbit sinuses.

MATERIAL AND METHODS

After sinus-floor elevation procedure, an experimentally devised mini-implant (4 mm in length and 3 mm in diameter) was placed in eight rabbits. For the experimental group, an HAC membrane was placed onto the elevated sinus mucosa prior to implant placement. The animals were allowed a healing period of either 4 or 8 weeks. Microcomputed tomography and histologic analyses were performed.

RESULTS

All implants placed at the thin lateral bony wall were histologically osseointegrated. The topography of the newly formed bone appeared to slope gently from the medial side down to the lateral side. The volume of new bone was significantly greater in the experimental group than in the control group at 4 weeks (P < 0.05), but not at 8 weeks. However, none of the samples in the two groups was entirely covered to the apex by bone tissue.

CONCLUSIONS

It can be concluded that using the HAC membrane in combination with placement of an implant resulted in substantial bone formation around the implant, which might have been influenced by the proximity of the axial bony wall.