The influence of bone block graft position on bone dimensional changes in staged onlay horizontal ridge augmentation: A 6-month retrospective cohort study

OBJECTIVES

To analyze changes in bone dimensions and their modulating factor in bone dimensions 6 months after horizontal ridge augmentation using autogenous bone grafts.

MATERIALS AND METHODS

Thirty-eight patients with horizontally atrophic alveolar ridges of a single edentulous tooth at the maxillary anterior site were divided into two groups based on the fixation position of the bone block during ridge augmentation surgery (H0, vertical distance from the upper edge of the bone block to the alveolar crest). Patients were classified into a crestal level (CL) group if H0 ≤ 1 mm and a sub-crestal level (SCL) group if H0 > 1 mm. The width and height of the alveolar ridge were recorded using CBCT both before and 6 months after the augmentation procedure.

RESULTS

The CL group comprised 20 patients with 23 implants, whereas the SCL group comprised 18 patients with 22 implants. All the augmentation sites exhibited vertical bone resorption. Vertical bone resorption in the SCL group (1.94 ± 2.11 mm) was significantly higher than that of the CL group (0.61 ± 0.64 mm). The SCL group showed significantly lower horizontal bone gain than the CL group (SCL: 1.02 ± 2.30 mm; CL: 3.19 ± 3.17 mm) at the cervical level. Peri-implant marginal bone loss increased significantly in the SCL group (1.00 ± 2.71 mm) compared to the CL group (0.64 ± 0.40 mm).

CONCLUSION

The bone height decreased after horizontal ridge augmentation using autogenous onlay grafting. The fixation position of the bone block was a modulating factor. The SCL group showed more vertical bone loss, less horizontal bone gain 6 months after surgery, and more marginal bone loss after restoration.

Three-Dimensional Printed Patient-Specific Vestibular Augmentation: A Case Report

Background: The anterior maxilla is challenging regarding aesthetic rehabilitation. Current bone augmentation techniques are complex and 3D-printed bioceramic bone grafts can simplify the intervention. Aim: A four-teeth defect in the anterior maxilla was reconstructed with a 3D-printed synthetic patient-specific bone graft in a staged approach for dental implant delivery. Methods: The bone graft was designed using Cone-Beam Computed Tomography (CBCT) images. The bone graft was immobilized with fixation screws. Bone augmentation was measured on CBCT images at 11 days and 8 and 13 months post-surgery. A biopsy sample was retrieved at reentry (10 months post-augmentation) and evaluated by histological and micro-computed tomography assessments. The definitive prosthesis was delivered 5 months post-reentry and the patient attended a visit 1-year post-loading. Results: A total bone width of 8 mm was achieved (3.7 mm horizontal bone gain). The reconstructed bone remained stable during the healing period and was sufficient for placing two dental implants (with an insertion torque > 35 N·cm). The fractions of new bone, bone graft, and soft tissue in the biopsy were 40.77%, 41.51%, and 17.72%, respectively. The histological assessment showed no signs of encapsulation, and mature bone was found in close contact with the graft, indicating adequate biocompatibility and suggesting osteoconductive properties of the graft. At 1-year post-loading, the soft tissues were healthy, and the dental implants were stable. Conclusions: The anterior maxilla's horizontal ridge can be reconstructed using a synthetic patient-specific 3D-printed bone graft in a staged approach for implant placement. The dental implants were stable and successful 1-year post-loading.

Horizontal ridge augmentation in the maxillary aesthetic region using the autogenous circular cortical-lamina anchoring technique: A case series study

AIM

This case series aimed to evaluate the effectiveness of the autologous circular cortical lamina-anchoring (CCA) technique for horizontal bone augmentation in the maxillary aesthetic region.

MATERIALS AND METHODS

A total of 25 patients with 28 implants underwent horizontal bone augmentation using CCA followed by implant placement and crown delivery. The primary outcome measures were alveolar ridge width (ARW) and buccal bone thickness (BBT), whereas the secondary outcome measures included marginal bone loss (MBL), mid-facial mucosal margin loss (MML), clinical assessment of peri-implant and aesthetic parameters, patient-reported outcome measures (PROMs), and implant survival rates.

RESULTS

All 25 patients with 28 implants completed the treatment, no dropouts occurred. After CCA, the mean ARW at 1, 2, and 4 mm below the alveolar crest significantly increased from 2.38 ± 0.48, 2.85 ± 0.51, and 3.21 ± 0.53 mm to 6.80 ± 0.48, 6.99 ± 0.50, and 8.08 ± 0.52 mm, respectively. At the 3-year follow-up, the mean BBT0 , BBT2 , and BBT4 slightly decreased from 2.51 ± 0.26, 2.63 ± 0.31, and 2.75 ± 0.29 mm to 2.43 ± 0.27, 2.51 ± 0.30, and 2.64 ± 0.28 mm, respectively. Although the overall MBL was <0.15 mm, the results were statistically significant. The mean MML at the 3-year follow-up was 0.02 mm. All implant sites showed acceptable peri-implant and aesthetic outcomes. Incisions healed without complications, and no significant differences in PROMs observed at any time point. The 3-year follow-up showed a 100% implant survival rate.

CONCLUSION

The autologous CCA technique is a useful method for increasing ARW and maintaining BBT in the maxillary aesthetic region.

Retrospective analysis of augmentation procedures with umbrella screws, a novel tenting technique: a consecutive case series in 279 patients

OBJECTIVES

The consecutive case series accesses the results and experiences of ridge augmentation using an umbrella screw tenting technique.

METHOD AND MATERIALS

In total, 279 patients were treated between 26 May 2015 and 16 June 2021, including horizontal and vertical ridge defects. Sex, age, smoking behavior, jaw, graft material, soft tissue thickness, extent of horizontal/vertical augmentation, resorption rate, and occurrence of early/late exposure were evaluated. Bone gain was determined by resorption at the screw head. Only cases without premature screw removal were evaluated metrically (n = 201). All other augmentations were evaluated according to whether implantation was possible with or without further augmentation (n = 27). A target performance index was calculated, which should enable evidence-based comparability of different augmentation methods in future.

RESULTS

In total, 54 wound dehiscences (39 early, 15 late exposures) occurred, which corresponds to 24.08% of the augmented sites; 42 umbrella screws were removed prematurely. In all cases an implantation was possible at the desired position afterwards. Cases with a vertical augmentation component showed a higher prevalence of exposure (early, P = .000; late, P = .024). The extent of the vertical augmentation was only relevant for early exposure (P = .048). Mean bone gain of 4.23 ± 1.69 mm horizontally and 4.11 ± 1.99 mm vertically could be achieved. Regression analysis showed that there was no limit in horizontal/vertical direction. Mean percentage target performance index was 75.90 ± 20.54 for vertical and 82.25 ± 16.67 for horizontal portions.

CONCLUSION

The umbrella technique is an effective augmentation method, which can be applied to any defect morphology.

Dimensional changes after horizontal and vertical guided bone regeneration without membrane fixation using the retentive flap technique: A 1-year retrospective study

AIM

To evaluate the dimensional changes after horizontal and vertical guided bone regeneration (GBR) without membrane fixation using the retentive flap technique.

METHODS

This study retrospectively examined two cohorts that received vertical or horizontal ridge augmentations (VA or HA groups). GBR was performed using particulate bone substitutes and resorbable collagen membranes. The augmented sites were stabilized using the retentive flap technique without any additional membrane fixation. The augmented tissue dimensions were assessed using cone-beam computed tomography at preoperative, immediately postoperative (IP), 4 months (4M), and 1 year (1Y).

RESULTS

Postoperative vertical bone gain in 11 participants of VA group amounted to 5.96 ± 1.88 mm at IP, which decreased to 5.53 ± 1.62 at 4M and to 5.26 ± 1.52 mm at 1Y (intragroup p < 0.05). The horizontal bone gain at IP in 12 participants amounted to 3.98 ± 2.06 mm, which decreased to 3.02 ± 2.06 at 4M and to 2.48 ± 2.09 mm at 1Y (intragroup p < 0.05). The mean implant dehiscence defect height after 1Y was 0.19 ± 0.50 mm in the VA group, and 0.57 ± 0.93 mm in the HA group.

CONCLUSION

GBR without membrane fixation using the retentive flap technique seems to preserve the radiographic bone dimensions of vertically augmented sites. This technique may be less effective at preserving the width of the augmented tissue.

Horizontal guided bone regeneration on knife-edge ridges: A retrospective case-control pilot study comparing two surgical techniques

INTRODUCTION

Studies evaluating guided bone regeneration (GBR) on knife-edge ridges using absorbable membranes with staged approaches have reported various horizontal bone gains. This study compared the horizontal bone gain obtained via a conventional technique of GBR and a recently-reported technique. Bone loss during the healing process was also measured.

METHODS

Consecutive patients who underwent GBR on knife-edge ridges via a conventional technique (control group) or the Sausage Technique (test group) were included in this study. GBR was performed using a collagen membrane and deproteinized bovine bone mineral combined with an autogenous graft at a 1:1 ratio. Cone-beam computed tomography (CBCT) was performed preoperatively, postoperatively, and after the patient healed. Horizontal bone width was measured on CBCT images 2 mm apical from the top of the crest. The preoperative CBCT and posthealing CBCT were superimposed to calculate the bone gain after healing, and the preoperative and postoperative CBCT scans were superimposed to calculate the bone gain after surgery. Bone loss during healing was calculated by subtracting the width of the ridge after healing from the postoperative width.

RESULTS

The mean horizontal bone gain was significantly lower in the control group (2.7 ± 1.8 mm; 83.2%) than in the test group (5.3 ± 2.3 mm; 216.8%) (p = 0.003). The average horizontal bone loss between regeneration and implant placement was 0.9 mm in the control group (27.9%) and 2.1 mm in the test group (29.4%). While the absolute bone loss was significantly different (p = 0.012), the percentage of bone resorption was not (p = 0.608).

CONCLUSION

The new technique resulted in significantly more bone gain than a conventional GBR technique. The rate of graft resorption during healing was stable regardless of the amount of grafted material.

Effect of biologic materials on the outcomes of horizontal alveolar ridge augmentation: A retrospective study

PURPOSE

The purpose of this study was to investigate if the addition of biologic agents to a particulate bone graft enhances horizontal ridge augmentation outcomes in terms of bone dimensions, bone density, and successful implant placement.

MATERIALS AND METHODS

A retrospective chart review was done to assess the clinical and radiographic outcomes in 52 horizontal ridge augmentation sites in 43 patients. Information was gathered regarding surgical technique, type of graft material, biologic agents used (PRP or rhPDGF-BB), method of space maintenance, and achieved alveolar ridge width and bone density changes as quantified on CBCT scans.

RESULTS

The use of tenting screws, a resorbable membrane, and a combination of particulate allogenic and xenogenic bone graft material provided an average horizontal bone gain of 3.6 mm in the 52 augmented sites. There was no statistically significant difference observed in the amount of horizontal bone gain between sites treated with the addition of biologic agents (n = 21), or with a particulate bone graft alone (n = 31). A marginally statistically significant difference was found in the density of the grafted bone with the addition of biologics (p value = .0653).

CONCLUSION

The addition of biologic agents to the graft materials did not have a significant effect on the amount of horizontal bone gain or successful implant placement; however, it marginally enhanced the bone density of the grafted area.

Effect of postoperative steroids on clinical outcomes and radiographic findings of horizontal alveolar ridge augmentation: A retrospective study

BACKGROUND

The purpose of the study was to investigate if the prescription of oral postoperative steroids has an effect on clinical outcomes of horizontal ridge augmentation including implant placement and characteristics of the grafted bone.

METHODS

A retrospective chart review of 73 horizontal ridge augmentation cases was completed to assess the clinical outcomes, 53 of those cases were further assessed radiographically. Information was gathered regarding surgical technique, grafting materials, postoperative healing, medications used postoperatively, bone growth, and density changes as quantified on a cone-beam computed tomography (CBCT) scan. Statistical analysis was completed to identify whether the use of postoperative oral steroids altered outcomes.

RESULTS

Steroids were used postoperatively following various horizontal ridge augmentation procedures. The use of tenting screws and resorbable membranes with a combination of osseous allograft and xenograft was used in 73 cases, 53 of which had preoperative and postoperative CBCT scans. Graft exposure occurred in five of the cases (9%), with the majority (n = 4) among those with postoperative steroids, but this was not statistically significant (P-value = 0.6510). Use of steroids was also not significantly associated with the number of courses of antibiotics (P-value > 0.05), but it was significantly associated with increased number of postoperative visits (P-value < 0.05). Among the subset for radiographic analysis (n = 53), there were significant clinical and radiographic dimensional changes in alveolar ridge width with an average horizontal bone gain of 3.6 mm. There were no statistically significant differences found in radiographic linear bone gain or clinical outcomes with the addition of steroids. A marginally statistically significant in the density of grafted bone was found with the addition of steroids (P-value > 0.05).

CONCLUSION

The prescription of postoperative steroids did not make a significant difference in clinical outcomes, success of implant placement or on radiographic assessment of grafted sites following horizontal alveolar ridge augmentation.

Autogenous interpositional block graft vs onlay graft for horizontal ridge augmentation in the mandible

BACKGROUND

Interpositional block graft revealed promising results in vertical ridge augmentation in the mandible, while scarce evidence is available regarding the use of interpositional block graft for horizontal ridge augmentation in the mandible.

PURPOSE

To compare the efficacy of autogenous block interpositional graft vs onlay graft in terms of horizontal ridge augmentation in the mandible.

MATERIALS AND METHODS

Twenty patients were randomly divided in two groups interpositional and onlay groups, using autogenous blocks harvested from the mandibular symphysis as the donor site. For the interpositional group, the mandibular ridge was split and the harvested block was inserted in the created space and fixated using titanium screws. For the onlay group, the defect site was decorticated and the harvested block was firmly fixated buccally using titanium screws. Immediate and 4 months postoperative cone beam computed tomography scans were taken for assessment.

RESULTS

In the interpositional group, the mean preoperative bone width was 3.85 ± 0.6 mm, after 4 months, the mean bone width was 8.84 ± 0.54 mm. While in the onlay group, the mean preoperative bone width was 3.74 ± 0.83 mm while after 4 months the mean bone width was 7.37 ± 1.98 mm. this was statistically significant.

CONCLUSION

Within the limits of this study, interpositional block graft appears to be a viable treatment option for horizontal ridge augmentation in the mandible.

Long-term Evaluation of Peri-implant Bone Level after Reconstruction of Severely Atrophic Edentulous Maxilla via Vertical and Horizontal Guided Bone Regeneration in Combination with Sinus Augmentation: A Case Series with 1 to 15 Years of Loading

BACKGROUND

To the best of the authors' knowledge, there is very limited clinical data on the outcomes of simultaneous guided bone regeneration (GBR) for horizontal and/or vertical bone gain for the reconstruction of severely atrophic edentulous maxilla. Therefore, the purpose of the clinical series presented herein was to clinically evaluate long-term horizontal and vertical bone gain, as well as implant survival rate after reconstruction of severely atrophic edentulous maxillary ridges.

MATERIAL AND METHODS

Sixteen patients (mean age: 64.6 ± 14.6 years of age) were consecutively treated for vertical and/or horizontal bone augmentation via GBR in combination with bilateral sinus augmentation utilizing a mixture of autologous and anorganic bovine bone. Implant survival, bone gain, intraoperative/postoperative complications and peri-implant bone loss were calculated up to the last follow-up exam.

RESULTS

Overall, 122 dental implants were placed into augmented sites and have been followed from 12 to 180 months (mean: 76.5 months). Implant survival was 100% (satisfactory survival rate of 97.5%). Mean bone gain was 5.6 mm (max: 9 mm; min: 3 mm) While vertical bone gain was 5.1 ± 1.8 mm; horizontal bone gain was 7.0 ± 1.5 mm. No intraoperative/postoperative complications were noted. Mean peri-implant bone loss values were consistent within the standards for implant success (1.4 ± 1.0 mm). At patient-level, only one patient who had three implants presented with severe peri-implant bone loss.

CONCLUSION

Complete reconstruction of an atrophied maxilla can be successfully achieved by means of guided bone regeneration for horizontal and/or vertical bone gain including bilateral sinus augmentation using a mixture of anorganic bovine bone and autologous bone.