Maxillary Alveolar Defects Research Articles

Cortical Mandibular Bone Blocks Grafts and Piezoelectric Surgery in Complex Anterior Maxillary Alveolar Defects: A Case Report and Literature Review

The aim of this study is to assess the indication and efficacy of alveolar ridge reconstructions for complex horizontal and vertical augmentation procedures in the maxillary anterior area with Cortical Mandibular Bone Block Grafts (CMBBG). Localized alveolar three-dimensional bone defects are among the most challenging problems in surgical implant dentistry. Treatment protocols, such as short implants or small diameter implants are not always offering the desired clinical and esthetic results. The autogenous augmentation procedure can serve as an option, which allows a more biological reconstruction of the vertical and horizontal dimension of a complex bone defect in order to obtain sound replicas of natural teeth. The clinical case of a cortical autogenous block graft in an anterior complex maxillary defect is presented along with a literature review. The presented case and the selected articles demonstrate that cortical ramus bone block grafts show relatively low graft resorption, low donor site morbidity and high implant success rates.

Predifferentiated Gingival Stem Cell-Induced Bone Regeneration in Rat Alveolar Bone Defect Model.

Cleft alveolus, a common birth defect of the maxillary bone, affects one in 700 live births every year. This defect is traditionally restored by autogenous bone grafts or allografts, which may possibly cause complications. Cell-based therapies using the mesenchymal stem cells (MSCs) derived from human gingiva (gingiva-derived mesenchymal stem cells [GMSCs]) is attracting the research interest due to their highly proliferative and multilineage differentiation capacity. Undifferentiated GMSCs expressed high level of MSC-distinctive surface antigens, including CD73, CD105, CD90, and CD166. Importantly, GMSCs induced with osteogenic medium for a week increased the surface markers of osteogenic phenotypes, such as CD10, CD92, and CD140b, indicating their osteogenic potential. The objective of this study was to assess the bone regenerative efficacy of predifferentiated GMSCs (dGMSCs) toward an osteogenic lineage in combination with a self-assembling hydrogel scaffold PuraMatrix™ (PM) and/or bone morphogenetic protein 2 (BMP2), on a rodent model of maxillary alveolar bone defect. A critical size maxillary alveolar defect of 7 mm × 1 mm × 1 mm was surgically created in athymic nude rats. The defect was filled with either PM/BMP2 or PM/dGMSCs or the combination of three (PM/dGMSCs/BMP2) and the bone regeneration was evaluated at 4 and 8 weeks postsurgery. New bone formation was evaluated by microcomputed tomography and histology using Hematoxylin and Eosin staining. The results demonstrated the absence of spontaneous bone healing, either at 4 or 8 weeks postsurgery in the defect group. However, the PM/dGMSCs/BMP2 group showed significant enhancement in bone regeneration at 4 and 8 weeks postsurgery, compared with the transplantation of individual material/cells alone. Apart from developing the smallest critical size defect, results showed that PM/dGMSCs/BMP2 could serve as a promising option for the regeneration of bone in the cranio/maxillofacial region in humans.

Assessment of vertical ridge augmentation and marginal bone loss using autogenous onlay vs inlay grafting techniques with simultaneous implant placement in the anterior maxillary esthetic zone: A randomized clinical trial.

Bony reconstruction and dental rehabilitation of patients with posttraumatic anterior maxillary alveolar defects is a very complicated procedure. The aim of this study is the assessment of vertical ridge augmentation using autogenous onlay vs inlay bone grafting techniques in the anterior maxilla. Sixteen patients (40 implants) with vertically deficient anterior maxillary alveolar ridges were equally allocated into two groups; Autogenous block bone graft was harvested from the chin with simultaneous implant placement was done either onlay (control) or inlay (study). Radiographic assessment was performed preoperatively, 1 week and 6 months postoperatively. Assessment included measurements of linear changes in the vertical height on cross sectional cuts of cone beam computed tomography (CBCT) using special software. Finally, the amount of vertical gain and marginal bone loss in each group was compared to that of the other. Wound healing was uneventful for all cases except three cases of the onlay group showed wound breakdown and graft loss. The mean vertical bone gain in the control group was -0.02 mm while in the study was 3.34 mm. While the mean of the crestal bone loss of the control group was 4.77 mm and that of the study group was 1.65 mm. The final vertical bone gain was statistically significant in the study group, so the inlay bone grafting technique with immediate implant placement could be used successfully for vertical alveolar ridge augmentation in the esthetic zone.

Reconstruction and Implant-Supported Rehabilitation of an Iatrogenically Caused Maxillary Alveolar Defect.

Defects of the oral and maxillofacial region may arise from several reasons such as trauma, infection, cyst, tumor, medication related osteonecrosis of the jaw, and misuse of some irritant agents. For reconstruction, autogenous grafts remain the gold standard among the alternatives. In our case, a 42-year-old woman referred to our clinic for implant-supported fixed bridge rehabilitation of her edentulous and defected left 2nd premolar and 1st molar region. In examinations, devitalizing agent-dependent large defect was observed. Anterior iliac crest (AIC) grafting technique was preferred for reconstruction. Consecutively, 16-week bone healing and 3-month implant osseointegration periods were uneventful. After fabrication of the implant-supported fixed bridge, the patient was followed up for 2.5 years with no signs of bone resorption, gingival inflammation, and pain. AIC grafting and implant-borne fixed bridges seem stable and satisfactory methods for large maxillofacial defects.

Comparative Volume Analysis of Alveolar Defects by 3D Simulation.

A precise volumetric assessment of maxillary alveolar defects in patients with cleft lip and palate can reduce donor site morbidity or allow accurate preparation of bone substitutes in future applications. However, there is a lack of agreement regarding the optimal volumetric technique to adopt. This study measured the alveolar bone defects by using two cone-beam computed tomography (CBCT)-based surgical simulation methods. Presurgical CBCT scans from 32 patients with unilateral or bilateral clefts undergoing alveolar bone graft surgery were analyzed. Two hands-on CBCT-based volumetric measurement methods were compared: the 3D real-scale printed model-based surgical method and the virtual surgical method. Different densities of CBCT were compared. Intra- and inter-examiner reliability was assessed. For patients with unilateral clefts, the average alveolar defect volumes were 1.09 ± 0.24 and 1.09 ± 0.25 mL (p > 0.05) for 3D printing- and virtual-based models, respectively; for patients with bilateral clefts, they were 2.05 ± 0.22 and 2.02 ± 0.27 mL (p > 0.05), respectively. Bland–Altman analysis revealed that the methods were equivalent for unilateral and bilateral alveolar cleft defect assessment. No significant differences or linear relationships were observed between adjacent different densities of CBCT for model production to obtain the measured volumes. Intra- and inter-examiner reliability was moderate to good (intraclass correlation coefficient (ICC) > 0.6) for all measurements. This study revealed that the volume of unilateral and bilateral alveolar cleft defects can be equally quantified by 3D-printed and virtual surgical simulation methods and provides alveolar defect-specific volumes which can serve as a reference for planning and execution of alveolar bone graft surgery.

Assessment of three dimensional bone augmentation of severely atrophied maxillary alveolar ridges using prebent titanium mesh vs customized poly-ether-ether-ketone (PEEK) mesh: A randomized clinical trial.

Alveolar bone grafting techniques and dental rehabilitation of patients with maxillary alveolar defects is a very challenging and costly procedure. Various methods have been described to reconstruct these defects in order to facilitate the placement of dental implants. The aim of this study was to assess three dimensional (3D) maxillary ridge augmentation using two innovative, accurate, and time saving protocols. Sixteen patients (32 implants) with vertically and horizontally deficient maxillary alveolar ridges, were equally allocated into 2 groups; a mix of particulate autogenous and xenogenic bone grafts loaded in a prebent titanium mesh (Control group) vs patient specific poly-ether-ether ketone meshes (Study group). Radiographic assessment was performed preoperatively, 1 week and 6 months postoperatively. Assessment included measurements of linear changes in the vertical and horizontal dimensions on cross sectional cuts of cone beam computed tomography using special software. Finally; the percentage of 3D bone gain in each group was compared to that of the other. Wound healing was uneventful for all cases except one patient in each group were the meshes were exposed 2 weeks' postsurgery. There was no statistical significance between both groups (P value = 0.2). Within the limitations of the sample size of this study, both techniques could be used as a successful method of ridge augmentation with no statistical significance between them.

Evaluation of BMMSCs-EPCs sheets for repairing alveolar bone defects in ovariectomized rats

The aim of this paper is to investigate the effect that bone marrow mesenchymal stem cells (BMMSCs) - endothelial progenitor cells (EPCs), BMMSCs and EPCs sheets have on repairing maxillary alveolar defects in ovariectomized (OVX) rats. In this study, after identification using multi-lineage differentiation and flow cytometry, BMMSCs and EPCs were isolated from female rats. The BMMSCs-EPCs, BMMSCs and EPCs sheets were detected by hematoxylin-eosin (H&E) staining, alkaline phosphatase (ALP) staining and qRT-PCR. Defects were created in maxillary alveoli and repaired with BMMSCs-EPCs, BMMSCs and EPCs sheets in OVX rats. The repair effects were determined by histological staining and micro-CT analysis at 2, 4 and 8 weeks after implantation. We aim to clarify whether BMMSCs-EPCs sheets are more effective in repairing alveolar bone defects than are BMMSCs and EPCs sheets in OVX rats. The results show that the osteogenic potential and the effect of bone repair are greater in the BMMSCs-EPCs sheet group and that this group has a higher ability to repair alveolar bone defects in OVX rats. These results suggest that BMMSCs-EPCs sheets have potential in clinical applications for treating humans with osteoporosis.

Amniotic fluid-derived stem cells mixed with platelet rich plasma for restoration of rat alveolar bone defect.

Stem cells isolated from the amniotic fluid have been shown as a promising candidate for cell therapy and tissue engineering. However, the experimental and preclinical applications of amniotic fluid-derived stem cells (AFSCs) in the very field of maxillofacial bone tissue engineering are still limited. In this study, rat AFSCs were successfully harvested and characterized in vitro. The rat AFSCs showed typical fibroblastoid morphology, stable proliferation activity and multi-differentiation potential. Flow-cytometry analysis demonstrated that these cells were positive for CD29, CD44, and CD90, while negative for hematopoietic markers such as CD34 and CD45. The regenerative performance of AFSCs-premixed with platelet rich plasma (PRP) gel in restoration of alveolar bone defect was further investigated using a modified rat maxillary alveolar defect model. Micro-computer tomography and histological examination showed a superior regenerative capacity of AFSCs-premixed with PRP gel at both 4 and 8 weeks after operation comparing with control groups. Moreover, the implanted AFSCs can survive in the defect site and directly participate in the bone tissue regeneration. Taken together, these results indicated the feasibility of an AFSCs-based alveolar bone tissue engineering strategy for alveolar defect restoration.

Success of Maxillary Alveolar Defect Repair in Rats Using Osteoblast-Differentiated Human Deciduous Dental Pulp Stem Cells

The use of cell-based therapies represents one of the most advanced methods for enhancing the regenerative response in craniofacial abnormalities. The main aim of this study was to evaluate the regenerative potential of human dental pulp stem cells, isolated from deciduous teeth, for reconstructing maxillary alveolar defects in Wistar rats. Human deciduous dental pulp stem cells were isolated and stimulated to differentiate into osteoblasts in culture media. Maxillary alveolar defects were created in 60 Wistar rats by a surgical procedure. Then, on the basis of the type of graft used to repair the bone defect, the rats were divided into 6 equal groups: groups 1 and 2, transplantation of iliac bone graft; groups 3 and 4, transplantation of stem cells derived from deciduous dental pulp in addition to collagen matrix; groups 5 and 6, transplantation of just collagen matrix. Then, fetal bone formation, granulation tissue, fibrous tissue, and inflammatory tissue were evaluated by hematoxylin-eosin staining at 1 month (groups 1, 3, and 5) and 2 months (groups 2, 4, and 6) after surgery, and data were analyzed and compared using the Fisher exact test. Maximum fetal bone formation occurred in group 2, in which iliac bone graft was inserted into the defect area for 2 months; there also were significant differences among the groups for bone formation (P = .009). In the 1-month groups, there were no significant differences between the control and stem cell-plus-scaffold groups. There were significant differences between the 2-month groups for fetal bone formation only between the control and scaffold groups (P = .026). The study showed that human dental pulp stem cells are an additional cell resource for repairing maxillary alveolar defects in rats and constitute a promising model for reconstruction of human maxillary alveolar defects in patients with cleft lip and palate.

Prosthetic Management Of A Maxillary Alveolar Defect With An Implant-Retained Fixed Prosthesis: A Clinical Report

Dentoalveolar defects resulting in the loss of alveolar ridge and attached mucosa is generally a challenge for the clinician to restore the defect area. The aim of this clinical report is to describe the prosthetic management of a maxillary alveolar defect. Treatment included 4 implants with a maxillary implant-retained fixed prosthesis. The esthetic and functional requirements of the patient were fulfilled.

Effects of Hydroxyapatite on Bone Graft Resorption in an Experimental Model of Maxillary Alveolar Arch Defects

Most commonly used treatments use autologous bone grafts to address bony defects in patients with cleft palate. Major disadvantages of autogenous bone grafts include donor site morbidity and resorption. Suggestions to overcome such problems include biomaterials that can be used alone or in combination with bone. We examined the effect of hydroxyapatite cement on bone graft resorption in a rabbit maxillary alveolar defect model. We divided 16 young adult albino New Zealand rabbits into two groups. A defect 1 cm wide was created in each rabbit’s maxillary arch. In Group 1, the removed bone was disrupted, and the pieces were replaced in the defect. In the other group, the pieces were replaced after mixing (1:1) with hydroxyapatite cement. Quantitative computed tomographic evaluation of these grafts was performed in axial and coronal planes for each rabbit at 2 and 12 weeks. In axial images at 12 weeks, the group without cement showed mean bone resorption of 15%. In the cement group, a mean volumetric increase of 68% was seen. No resorption occurred when bone grafts were mixed with hydroxyapatite cement.

Prenatal Cleft Lip and Maxillary Alveolar Defect Repair in a 2-Step Fetal Lamb Model

As there is no satisfying animal model simulating the complex cleft lip and palate anatomy in a standardized defect on one hand, and comprising the possibilities for extensive surgical procedures on the other hand, an improved fetal lamb model for cleft surgery was developed. Prior to the main study with 16 animals, a pilot study with 4 lambs was conducted. In the pilot study, the unilateral defect was induced at 75 days of gestation. Within 22 days the defect was repaired in 3 lambs; 1 lamb remained unoperated. Disappointing results from the pilot study led to an earlier defect induction (60 to 64 days of gestation) and earlier repair (71 to 84 days) in the main study with 16 lambs. The subsequent delayed repair of the defect was carried out using a Tennison-Randall technique in 10 lambs. In 4 lambs the defect was repaired postnatal, using the same technique. Two lambs had to be excluded from the study. After being euthanized, all animals were investigated macro- and microscopically. According to our criteria, the esthetic results ranged from satisfactory to good. Cutis and mucosa showed a full recovery whereas subcutis and the orbicularis oris muscle showed healing with scar formation. On average the operated lips were 9% shorter and were also thinner than the contralateral control side. In this study, the results of the closure of a standardized lip and maxillary alveolar defect in several stages of gestation were documented. Early intervention led to better esthetic results, but increased the risk of abortion by 25%. There was no prevention of scarring in subcutaneous and muscle tissue. Because there was no alignment of the orbicularis oris muscle, the goal of a functional perfect result was not achieved.

RhBMP-4 Gene Therapy in a Juvenile Canine Alveolar Defect Model

Autologous bone grafts have the disadvantages of donor-site pain and morbidity, finite supply, increased costs, and prolonged hospitalizations. Using a juvenile canine model, the authors hypothesized that recombinant human (rh) bone morphogenetic protein (BMP)-4 gene therapy-treated alveolar defects would promote bone healing and canine tooth eruption equal to their autografted counterparts. Sixty-five maxillary alveolar defects were created in juvenile foxhound dogs with a mean age of 80.8 days. Nineteen defects were treated with DNA plasmid encoding rhBMP-4, 16 defects were autografted, 15 defects contained scaffold only, and 15 defects were left unrepaired. At 4 and 12 weeks after surgery, bone density and tooth eruption were measured, respectively. Data were subjected to one-way analysis of variance testing with statistical significance established at p < 0.05. At 4 weeks, the bone densities in the rhBMP-4, autografted, scaffold-only, and defect-only groups were 31.2 +/- 6.5, 30.5 +/- 8.1, 18.4 +/- 3.8, and 15.2 +/- 4.0 percent, respectively. A significant effect (p < 0.05) was observed between the rhBMP-4 gene therapy-treated and autografted groups compared with the scaffold-only and defect-only groups. At 12 weeks, the rates of tooth eruption measured in the rhBMP-4, autografted, scaffold-only, and defect-only groups were 67.4 +/- 15.8, 58.3 +/- 18.8, 52.7 +/- 16.2, and 45.0 +/- 13.3 percent, respectively. A significant effect (p < 0.05) was observed between the rhBMP-4 gene therapy-treated and defect-only groups. In the present studies, rhBMP-4 gene therapy was equivalent to autografting and superior to the scaffold-only and unrepaired defect in bone regeneration and tooth eruption. With decreased morbidity and cost, rhBMP-4 gene therapy may ultimately become an alternative to autografting to repair bony defects.

Use of the buccal fat pad in the reconstruction and prosthetic rehabilitation of oncological maxillary defects

We evaluated the effectiveness of the buccal fat pad as a pedicled flap for intraoral reconstruction after partial maxillectomy for neoplastic disease in 24 patients, and subsequently, in providing support for a denture. In all patients the buccal fat pad was covered with a split-skin graft and an acrylic plate. There was complete healing of the buccal fat pad flap within 6 weeks in 18 patients with no major complications, and minimal effects on speech and eating. In six cases there was partial dehiscence of the flap, which healed spontaneously in one patient and was repaired with local flaps in two others. There were no cases of complete breakdown of the flap. Eight patients so far have been rehabilitated with small dentures. In conclusion, the buccal fat pad flap is a simple, quick, and reliable method of reconstruction of small to medium-sized posterior maxillary alveolar defects.

Repair of maxillary alveolar cleft defects with two different bioabsorbable implants: an experimental study in growing rabbits

Two different bioabsorbable implants and their ability to promote bone formation in repair of experimental maxillary defects were investigated. A poly-L/D-lactide mesh and a two-layer composite membrane consisting of a film made of a copolymer of L-lactic acid and e-caprolactone combined with the polylactide mesh were used as implants. A standard alveolar defect was made bilaterally in the maxilla and filled with autogenous bone grafts in 30 growing rabbits. Follow-up was 10 weeks. Three experimental groups were formed: (1) defect covered with polylactide mesh versus control defect without implant, (2) defect covered with composite membrane versus control defect, and (3) defect covered with membrane on one side and with mesh on the other. Radiological, histological and histomorphometric evaluations were performed. In histomorphometric measurements, a significantly larger quantity of bone was observed in the composite membrane-covered defects compared with the polylactide mesh-covered and the control defects. Osteogenic activity was also highest in the membrane-covered defects. The bioabsorbable composite membrane appears to promote healing of experimental maxillary alveolar defects in accordance with the principle of guided tissue regeneration. The polylactide mesh alone was less potent in promoting healing of the defect, although an enhancing effect on osteogenic activity was observed.