Elevation of the maxillary sinus membrane for de-novo bone formation: First results of a prospective study in humans

Masticatory function in edentulous patients wearing implant overdentures after graftless maxillary sinus membrane elevation

BACKGROUND

Graftless sinus floor augmentation shows good results in bone gain, radiology and implant survival. Clinically, this technique can be recommended as an alternative to conventional procedures using augmentation materials.

OBJECTIVES

This study aims to assess masticatory performance, masticatory ability and patient satisfaction after graftless sinus floor augmentation.

METHODS

The study group consisted of patients who had received a graftless sinus lift procedure in a split-mouth design and was compared to patients with maxillary implant-supported overdentures without augmentation and a natural dentition group. To assess objective masticatory performance, the mixing ability test was performed. Three questionnaires were used to assess patient reported outcomes related to mastication and patient satisfaction.

RESULTS

Each group included ten patients. Both the graftless sinus lift group and the edentulous control group had a worse masticatory performance compared to the natural dentition group. Masticatory ability, measured by patient reported outcomes, was not different between the graftless sinus floor augmentation group and implant-retained overdentures group without augmentation, but the natural dentition group showed better results. Thereby, the better the masticatory performance in patients with a graftless sinus membrane elevation the better the patient satisfaction for 'prosthesis', 'appearance of prostheses', 'speech' and 'mastication and eating'.

CONCLUSIONS

Patients with implant-supported overdentures show inferior masticatory function compared to those with natural dentition. There were no significant differences in masticatory performance between patients with implant-retained overdentures, with or without graftless augmentation. The decision on the preferred procedure should consider additional factors such as anatomical, surgical-technical aspects and patient's preferences.

Human alveolar bone-derived mesenchymal stem cell cultivation on a 3D-printed PDLLA scaffold for bone formation

This study aimed to assess effects of 3-dimensionally (3D) printed poly-d,l-lactin (PDLLA) on human alveolar bone-derived mesenchymal stem cell (h-ABMSC) osteogenic proliferation and differentiation. Human ABMSCs were cultured and identified using flow cytometry and morphological analysis. Control and PDLLA experimental groups were assessed using a Cell Counting Kit-8 (CCK-8) to detect cellular cytotoxicity and proliferative activity. Real-time quantitative polymerase chain reaction was used to determine expression levels of osteogenesis genes including alkaline phosphatase (ALP), Runt-related transcription factor 2 (Runx-2), osteopontin (OPN), and osteocalcin (OCN). The results showed that h-ABMSCs were successfully cultured and revealed by microscopic observation. Human ABMSCs were spindle-shaped, with clustered and fish-like primary cells. Cell surface markers were negative for CD34 and positive for CD44 and CD90. PDLLA had no cytotoxicity. Human ABMSCs proliferated normally, and osteogenic differentiation of the cells was observed on the surface of PDLLA. Cellular proliferative activity and expression levels of osteogenesis-related genes of PDLLA and control groups showed no significant difference, including ALP, Runx-2, OPN, and OCN. These results suggest that 3D-printed PDLLA has good cell compatibility and biological activity.

Temporal and Permanent Changes Induced by Maxillary Sinus Lifting with Bone Grafts and Maxillary Functional Endoscopic Sinus Surgery in the Voice Characteristics—Systematic Review

Sinus surgery procedures such as sinus lifting with bone grafting or maxillary functional endoscopy surgery (FESS) can present different complications. The aims of this systematic review are to compile the post-operatory complications of sinus elevation with bone grafting and FESS including voice changes, and to elucidate if those changes are either permanent or temporary. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used, and the literature was exhaustively searched without time restrictions for randomized and non-randomized clinical studies, cohort studies (prospective and retrospective), and clinical case reports with ≥4 cases focused on sinus lift procedures with bone grafts and functional endoscopic maxillary sinus surgery. A total of 435 manuscripts were identified. After reading the abstracts, 101 articles were selected to be read in full. Twenty articles that fulfilled the inclusion criteria were included for analysis. Within the limitations of this systematic review, complications are frequent after sinus lifting with bone grafts and after FEES. Voice parameters are scarcely evaluated after sinus lifting with bone grafts and no voice changes are reported. The voice changes that occur after FESS include a decreased fundamental frequency, increased nasality, and nasalance, all of which are transitory.

Implant survival after graftless sinus floor augmentation in highly atrophic maxillae: a randomized controlled trial in a split mouth study

PURPOSE

The success rate of dental implants after graftless sinus augmentation versus conventional sinus augmentation surgery in atrophic maxillae in edentulous patients was investigated.

METHODS

This randomized study was performed in ten edentulous patients with marked maxillary atrophy. On the graftless side, the sinus membrane was lifted by a resorbable membrane. The control side was augmented with a mixture of autografts and xenografts. Implant placement followed 6 months postoperatively. Outcomes were implant survival, success of prosthetic rehabilitation and stability of vertical bone gain.

RESULTS

Ten patients were included. Postoperative radiology showed sufficient bone gain on both maxillary sides. Follow-up varied from 57 to 88 months. The conventional side showed significant (p = 0.041) more bone gain than the experimental side (respectively, 9.69 mm and 6.20 mm). A total of 59 implants were placed: 30 after conventional, 29 after graftless augmentation. One implant was lost on the conventional side and four on the experimental side. The implant survival was significantly higher on the conventional side (96.7% vs. 86.2%, p < 0.001, RR = 4.14). Prosthetic restoration was functionally successful in all cases.

CONCLUSION

Bone gain and implant survival were significantly lower in the non-grafted side versus the grafted side. Prosthetic rehabilitation was possible in all ten patients. The non-grafted technique may have some potential for clinical use, although it showed poorer results. Trial registration The Netherlands Trialregister. NTR NL3541 (NTR3696). Registered 20 January 2013, https://www.trialregister.nl/trial/3541 .

Patient's perception of recovery after sinus membrane elevation and blood coagulum compared with 1:1 mixture of autogenous bone graft and deproteinized porcine bone mineral. Secondary outcomes from a single-blinded randomized controlled trial

OBJECTIVE

The objective was to assess patient's perception of recovery after maxillary sinus membrane elevation (MSME) and blood coagulum (test) compared with maxillary sinus floor augmentation (MSFA) and 1:1 mixture of autogenous bone graft from the buccal antrostomy and deproteinized porcine bone mineral (DPBM) (control).

MATERIALS AND METHODS

Forty healthy patients were randomly allocated to test or control. Oral health-related quality of life (OHRQoL) was evaluated by Oral Health Impact Profile-14 (OHIP-14) at enrollment and 1 week postsurgical. Recovery was estimated by questionnaires and visual analog scale assessing pain, social and working isolation, physical appearance, eating and speaking ability, diet variations, sleep impairment, and discomfort after 1 week and 1 month. Mean differences were expressed with 95% confidence interval (CI). Association between OHRQoL and recovery was estimated. p-value below .05 was considered statistically significant.

RESULTS

Maxillary sinus membrane elevation revealed 2.1 less days of pain (p = .03, 95% CI: 0.2-4.1) and 1.2 days of sick leave (p = .01, 95% CI: 0.3-2.1) compared with MSFA. No significant difference was observed in eating and speaking ability, physical appearance, work performance, and sleep impairment. No significant association between impaired OHRQoL and recovery was observed. Females reported 4.77 higher OHIP-14 score compared with males (p = .01, 95% CI: 1.60-7.94), while association between age and OHIP-14 was -0.10 (p = .28, 95% CI: -0.28 to 0.08).

CONCLUSION

Maxillary sinus membrane elevation revealed significantly less days of pain and sick leave compared with MSFA. Harvesting of autogenous bone graft seems, therefore, to have a significant impact on perception of recovery.

Non-grafted versus grafted sinus lift procedures for implantation in the atrophic maxilla: a systematic review and meta-analysis of randomized controlled trials

The aim of this systematic review and meta-analysis was to critically evaluate the currently existing clinical evidence on the efficacy of graftless maxillary sinus membrane elevation for implantation in the atrophic posterior maxilla. A search protocol without limitations to November 2020 was followed by two independent researchers. Randomized controlled trials using the lateral window approach for graftless sinus membrane elevation were included. Uncontrolled, retrospective, non-comparative studies, case reports, and experimental studies in animals or cadavers were excluded. The search identified 2777 studies. Critical selection by two independent researchers then led to the inclusion of a total of nine studies. A risk of bias assessment was applied using the revised Cochrane risk-of-bias tool for randomized trials. A meta-analysis was conducted for seven studies. Results showed a high overall implant survival rate in both the graftless and bone-grafted sinus lift groups (97.92% and 98.73%, respectively). The graftless sinus lift group showed a significantly lower vertical bone height gain, with a mean difference of -1.73mm (P=0.01), and a significantly lower bone density, with a mean difference of -94.7 HU (P<0.001). The implant stability quotient values did not differ significantly between the test and control groups (P=0.07).

Pre-implantological bone formation in the floor of the maxillary sinus in a self-supporting space

INTRODUCTION

In edentulous patients the form and size of the maxillary sinus vary greatly. Therefore sinus floor augmentation is a standard procedure for implantological purposes. As the sinus membrane cannot be characterized as periosteum, various augmentation materials are used.

HYPOTHESIS

an artificially generated space underneath the sinus membrane in the floor of the sinus will lead to spontaneous callus forming and a stable bony consolidation without augmentation material.

METHODS

Ten edentulous patients with highly atrophic maxillae were selected. Augmentation of the sinus floor was carried out in a split-mouth study design: On one side a combination of autogenous and xenogenous bone was used, and on the contralateral side a sinus membrane elevation was performed without using any substitutes. After a 6-month interval bone specimens from the test regions were harvested during implant placement.

RESULTS

Clear histological evidence of new bone formation was found in all human bone specimens. An active de-novo bone formation process could be proven by the presence of Haversian systems (osteons) displaying osteoblastic and osteoclastic activity.

CONCLUSION

In the maxillary sinus of edentulous patients a spontaneous callus-derived de-novo bone formation is possible by elevating the sinus membrane without using augmentation materials.

Does intraoperative perforation of Schneiderian membrane during sinus lift surgery causes an increased the risk of implants failure?: A systematic review and meta regression analysis

PURPOSE

There is still debate whether intraoperative Schneiderian membrane (SM) perforation in the maxillary sinus lift causes an increase the risk of implants failure. The aim of this study was to assess an association between SM perforation and implants loss following the maxillary sinus lift.

MATERIALS AND METHODS

A systematic review and meta-analysis of clinical studies assessing association between SM perforation and implants failure based on PRISMA was conducted. Three major databases were used to gather research dating from their respective inception up until March 2018. All clinical studies expressly reported the number of the SM perforation and implants loss that installed in the perforated and nonperforated sinuses were included. The statistical analyses used were Pearson's correlation, simple linear regression, and meta regression. The risk ratio (RR) of implant loss between perforated and nonperforated sites was estimated.

RESULTS

A total of 2947 patients with 3884 maxillary sinuses augmentations who received 7358 implants, enrolled in 58 studies were included in this study. There was a significant relationship between the implants' failure and SM perforation according to simple linear regression (P < .001) and meta regression analysis (P = .06). There was a significant decrease (moderate quality evidence) in implant loss in the nonperforated sinuses compared to perforated sunrises (RR = 2.17, CI: 1.52-3.10, P = .001). There was also no significant association between implant loss in the perforated sinuses and the surgical devices used (piezosurgical or rotary), surgical approach applied (lateral or crestal sinus lift), barrier membrane used and type of bone grafting materials.

CONCLUSION

The results of this study showed that an intraoperative SM perforation could increase the risk of implant failure after the sinus lift surgery.

The Use of Poly-d,l-lactic Acid (PDLLA) Devices for Bone Augmentation Techniques: A Systematic Review

Poly-d,l-lactic acid (PDLLA) has been proposed in dentistry for regenerative procedures in the form of membranes, screws, and pins. The aim of this review was to evaluate the efficacy of bone augmentation techniques using PDLLA devices. A literature search was carried out by two independent and calibrated reviewers. All interventional and observational studies assessing the efficacy of bone augmentation techniques using PDLLA devices were included. Six studies were included. The relevant variability of design and methods impeded any qualitative or quantitative comparison. Ease of handling, absence of a re-entry phase, moldability of foils, and good soft-tissue response were appreciated characteristics of PDLLA devices. Some drawbacks such as the risk of membrane exposition, a prolonged adsorbability, and a tendency to a fibrous encapsulation of the PDLLA devices have been described, although the clinical significance of these findings is unclear. Clinical data about PDLLA devices for bone regeneration are very scarce and heterogenous. Well-designed randomized controlled trials comparing the use of PDLLA foils and pins with conventional membranes for bone regeneration are strongly encouraged in order to understand the real clinical benefits/drawbacks of this technique.

Mesenchymal stem cells with osteogenic potential in human maxillary sinus membrane: an in vitro study

OBJECTIVES

The aim of our study is to prove and validate the existence of an osteogenic progenitor cell population within the human maxillary Schneiderian sinus membrane (hMSSM) and to demonstrate their potential for bone formation.

MATERIALS AND METHODS

Ten hMSSM samples of approximately 2 × 2 cm were obtained during a surgical nasal approach for treatment of chronic rhinosinusitis and were retained for this study. The derived cells were isolated, cultured, and assayed at passage 3 for their osteogenic potential using the expression of Alkaline phosphatase, alizarin red and Von Kossa staining, flow cytometry, and quantitative real-time polymerase chain reaction.

RESULTS

hMSSM-derived cells were isolated, showed homogenous spindle-shaped fibroblast-like morphology, characteristic of mesenchymal progenitor cells (MPCs), and demonstrated very high expression of MPC markers such as STRO-1, CD44, CD90, CD105, and CD73 in all tested passages. In addition, von Kossa and Alizarin red staining showed significant mineralization, a typical feature of osteoblasts. Moreover, alkaline phosphatase (ALP) activity was significantly increased at days 7, 14, 21, and 28 of culture in hMSSM-derived cells grown in osteogenic medium, in comparison to controls. Furthermore, osteogenic differentiation significantly upregulated the transcriptional expression of osteogenic markers such as ALP, Runt-related transcription factor 2 (Runx-2), bone morphogenetic protein (BMP)-2, osteocalcin (OCN), osteonectin (ON), and osteopontin (OPN), confirming that hMSSM-derived cells are of osteoprogenitor origin. Finally, hMSSM-derived cells were also capable of producing OPN proteins upon culturing in an osteogenic medium.

CONCLUSION

Our data showed that hMSSM holds mesenchymal osteoprogenitor cells capable of differentiating to the osteogenic lineage.

CLINICAL RELEVANCE

hMSSM contains potentially multipotent postnatal stem cells providing a promising clinical application in preimplant and implant therapy.

Do CBCT scans alter surgical treatment plans? Comparison of preoperative surgical diagnosis using panoramic versus cone-beam CT images

Cone beam CT and/or panoramic images are often required for a successful diagnosis in oral and maxillofacial surgery. The aim of this study was to evaluate if 3D diagnostic imaging information had a significant impact on the decision process in six different classes of surgical indications.

MATERIAL AND METHODS

Records of all patients who had undergone both panoramic X-ray and CBCT imaging due to surgical indications between January 2008 and December 2012 were examined retrospectively. In February 2013, all surgically relevant diagnoses of both conventional panoramic radiographs and CBCT scans were retrieved from the patient's charts. It was recorded whether (1) 3D imaging presented additional surgically relevant information and (2) if the final decision of surgical therapy had been based on 2D or 3D imaging.

RESULTS

A total of 253 consecutive patients with both panoramic radiographs and CBCT analysis were eligible for the study. 3D imaging provided significantly more surgically relevant information in cases of implant dentistry, maxillary sinus diagnosis and in oral and maxillofacial traumatology. However, surgical strategies had not been influenced to any significant extent by 3D imaging.

CONCLUSION

Within the limitations of this study it may be concluded that CBCT imaging results in significantly more surgically relevant information in implant dentistry, maxillary sinus diagnosis and in cases of oral and maxillofacial trauma. However, 3D imaging information did not alter significantly the surgical plan that was based on 2D panoramic radiography. Further studies are necessary to define indications for CBCT in detail.