Influence of Lateral-Medial Sinus Width on No-Grafting Inlay Osteotome Sinus Augmentation Outcomes

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.

Clinical and radiographic outcomes following transcrestal maxillary sinus floor elevation with injectable xenogenous bone substitute in gel form: a prospective multicenter study

Purpose

To investigate clinical and radiographic outcomes of transcrestal maxillary sinus floor elevation performed with an injectable xenograft in gel form, analyzing general, local and surgical variables possibly influencing the results.

Methods

Patients with residual crestal height < 5 mm underwent transcrestal sinus floor elevation with xenograft in gel form to allow the placement of a single implant. Simultaneous implant placement was performed when primary stability was ≥ 15 Ncm. Graft height was measured immediately after surgery (T0) and after 6 months of healing (T1). Univariate and multivariate regression models were built to assess associations between clinical variables with implant survival and graft height at T1.

Results

71 patients underwent transcrestal sinus floor elevation and 54 implants were simultaneously placed. Delayed implant placement (at T1) was possible in 5 cases out of 17 (29.4%), whereas in 12 patients (70.6%) implant insertion was not possible or required additional sinus grafting. Implant survival rate, with a follow-up varying from 12 to 32 months after loading, was 100%. Mean pre-operative bone height was 3.8 ± 1.0 mm, at T0 was 13.9 ± 2.2 mm and at T1 was 9.9 ± 2.8 mm. Bone height at T1 was negatively influenced by membrane perforation at surgery (p = 0.004) and positively influenced by immediate implant insertion (p < 0.001).

Conclusions

Transcrestal sinus floor elevation performed with injectable xenograft gel resulted in 100% implant survival rate. However, immediate implant insertion seems a crucial factor to preserve vertical bone gain: one-stage technique seems to be the most predictable approach to optimize clinical outcomes with this approach.

Trial registration clinicaltrials.gov, NCT05305521. Registered 31 March 2022—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT05305521.

Influence of anatomical factors related to maxillary sinus on outcomes of transcrestal sinus floor elevation

Background/purpose

Graft bone maturation and remodeling in the maxillary sinus require adequate angiogenesis and osteoprogenitor cells migration from the surrounding bony walls and Schneiderian membrane. This study aimed to evaluate the influence of anatomical factors related to maxillary sinus on the outcomes of transcrestal sinus floor elevation using cone-beam computed tomography (CBCT).

Materials and methods

Forty-five patients (63 elevated sites) were included in this study. CBCT were obtained preoperatively, immediately and 6 months after surgery. The anatomical features of residual bone height, maxillary sinus width, maxillary sinus angle and Schneiderian membrane thickness were measured on preoperative CBCT. Descriptive statistics and correlation analysis were conducted to evaluate the influence of anatomical factors on outcome parameters, including sinus lift height, graft bone resorption and marginal bone loss.

Results

The results showed that there was a positive correlation between sinus width and graft bone resorption. A significantly positive correlation between sinus angle and graft bone resorption was also found.

Conclusion

Our findings indicate that the anatomical factors of maxillary sinus (sinus width and sinus angle) have influence on the linear change of bone grafts after transcrestal sinus floor elevation.

Outcomes of implants placed after osteotome sinus floor elevation without bone grafts: a systematic review and meta-analysis of single-arm studies

Background

The aim of this study is to evaluate the implant survival/success rate, gain in alveolar bone height, crestal bone loss, and complications associated with implants placed in the posterior maxilla after osteotome sinus floor elevation without bone substitutes.

Methods

The electronic databases, such as MEDLINE, EMBASE, CENTRAL, and SCOPUS were systematically and manually searched for publications in peer-reviewed journals. The included articles were subjected to qualitative and quantitative analyses, and the meta-analysis was carried out for single-arm studies. Methodological quality assessment was made for all the included studies.

Results

The included studies were of moderate quality, with the overall implant success and survival rates of 98.3% and 97.9% respectively. The most frequent intra-surgical complication was sinus membrane perforation, accounting for 3.08% of the total implants with reported perforations. The overall crestal bone loss in patients with immediate implants placed with OSFE after a 5-year follow-up was 0.957 mm 95%CI (0.538, 1.377).

Conclusion

Within the limitations of this review, it can be concluded that the survival and success rates of implants placed immediately along with OSFE without any bone substitutes are acceptable and show adequate implant stability with less crestal bone loss over 5 years.

A Combined Lateral-Crestal Approach of Sinus Floor Elevation: Three Case Reports

This clinical report describes a combined lateral-crestal approach to elevate the sinus floor when placing implants on a wide maxillary posterior ridge. The buccally enlarged osteotomy broadens the vision of practitioners and facilitates access of instruments in the sinus. Compared with the traditional lateral approach of sinus lift, the proposed technique offers a more conservative treatment modality. A clinical study with sufficient subjects and long-term follow-up is needed to validate the potential and limitations of the proposed technique.

Influence of implant protrusion length on non-grafting osteotome sinus floor elevation with simultaneous implant: a 3- to 9-year retrospective study

BACKGROUND

This study analyzed the influence of implant protrusion length (IPL) on the possible factors that affect the long-term outcomes utilizing non-grafting osteotome sinus floor elevation (OSFE) with simultaneous implant placement, and to explore the optimal range of IPL.

MATERIALS AND METHODS

A retrospective study design was adopted. The clinical and radiographic data of 105 implants in 65 patients were collected after 3-9 (mean 5.04) years follow-up. IPL was divided into three groups (group1, IPL<2mm; group2, 2mm≤IPL<4mm; group3, IPL≥4mm). Endo-sinus bone gain (ESBG), peri-implant marginal bone loss (MBL), bone to implant contact length (BICL), and percentage of ESBG (%ESBG) were used to evaluate non-grafting OSFE. A Kaplan-Meier analysis was performed to assess the cumulative survival rate. Multiple linear regression model was used to explore the relationship between the possible influence factors and ESBG. Analysis of variance (ANOVA) was applied to explore the correlation of IPL with ESBG, MBL, BICL, and %ESBG.

RESULTS

A total of 102 implants in 62 patients fulfilled the survival criteria, giving the cumulative survival rates of 96.4% and 94.1% for implant-based analysis and patient-based analysis, respectively. The mean ESBG, MBL, and BICL at the latest follow-up were 1.95±0.88 mm, 0.58±0.68 mm, and 5.51±1.47 mm. ESBG was found to be positively correlated to IPL. A significant decreased bone formation efficiency was found when IPL was over 4 mm (P=0.02).

CONCLUSIONS

An optimal range of IPL within 4 mm was recommended for better long-term outcomes when applying non-grafting OSFE with simultaneous implant placement.

[Effect of anatomical parameters of maxillary sinus on the outcomes of transcrestal sinus lift]

OBJECTIVE

To investigate the effect of three anatomical parameters (maxillary sinus width, maxillary sinus angle, and residual bone height) on the outcomes of transcrestal sinus lift with simultaneous implant placement.

METHODS

A total of 60 maxillary sinuses in 42 patients were included in this study. All patients were treated with transcrestal sinus lift procedure associated with simultaneous implant placement using a composite graft material of autogenous bone and Bio-Oss. For each patient, beam computed tomography (CBCT) scans were performed preoperatively, immediately after surgery, and 6 months after surgery. The parameters were measured on the preoperative and postoperative CBCT images. The correlation of three anatomical parameters with graft resorption was analyzed using Pearson's correlation test.

RESULTS

The average residual bone height was (4.46±1.55) mm. The average width of maxillary sinus was (13.86±2.71) mm. The average sinus angle was 78.09°±10.27°. A significant positive correlation was observed between maxillary sinus width and graft resorption (P<0.01). A positive association was also found between sinus angle and graft resorption (P<0.01).

CONCLUSIONS

The findings show that graft bone resorption in elevated sinus has a positive correlation with the sinus width and sinus angle.

New bone formation after transcrestal sinus floor elevation was influenced by sinus cavity dimensions: A prospective histologic and histomorphometric study

OBJECTIVE

The aim of this multicenter prospective study was to analyze clinically and histologically the influence of sinus cavity dimensions on new bone formation after transcrestal sinus floor elevation (tSFE).

MATERIAL AND METHODS

Patients needing maxillary sinus augmentation (residual crest height <5 mm) were treated with tSFE using xenogeneic granules. Six months later, bone-core biopsies were retrieved for histological analysis in implant insertion sites. Bucco-palatal sinus width (SW) and contact between graft and bone walls (WGC) were evaluated on cone beam computed tomography, and correlations between histomorphometric and anatomical parameters were quantified by means of forward multiple linear regression analysis.

RESULTS

Fifty consecutive patients were enrolled and underwent tSFE procedures, and forty-four were included in the final analysis. Mean percentage of newly formed bone (NFB) at 6 months was 21.2 ± 16.9%. Multivariate analysis showed a strong negative correlation between SW and NFB (R²  = .793) and a strong positive correlation between WGC and NFB (R²  = .781). Furthermore, when SW was stratified into three groups (<12 mm, 12 to 15 mm, and >15 mm), NFB percentages (36%, 13% and 3%, respectively) resulted significantly different.

CONCLUSIONS

This study represented the first confirmation based on histomorphometric data that NFB after tSFE was strongly influenced by sinus width and occurred consistently only in narrow sinus cavities (SW <12 mm, measured between buccal and palatal walls at 10-mm level, comprising the residual alveolar crest).