Mechanical impairment on alveolar bone graft: A literature review

Evaluation of maxillary alveolar ridge formation and ridge continuity after secondary alveolar bone grafting using cancellous and cortico-cancellous bone graft in unilateral cleft alveolus using cone beam computed tomographic scan - a randomized controlled trial

PURPOSE

The aim of present study was to compare and evaluate the maxillary alveolar ridge formation and ridge continuity using cancellous and corticocanellous bone graft harvested from anterior iliac crest for complete secondary unilateral cleft alveolus defects.

MATERIAL AND METHOD

All patients were randomized into two groups for secondary alveolar bone grafting. Group I (n = 10) patients treated with cancellous particulate bone graft and group II (n = 10) patients treated with cortico-cancellous block graft. Maxillary alveolar ridge bone formation was assessed with the help of cone beam computed tomography (CBCT) scan using Planmeca Romexis Viewer 5.0 software. Maxillary alveolar ridge continuity was assessed with axial section of CBCT scan and clinical occlusal photograph. Preoperative CBCT scan and occlusal photographs were compared with post-op 6-month CBCT scan and occlusal photographs.

RESULT

The mean preoperative volume of cleft defect in group I was 4.2576 cm3 whereas in group II it was 4.2268 cm3. The mean postoperative bone bridge formation after 6 months in group I was 4.055 cm3 whereas in group II it was 3.8103 cm3. Preoperative and 6-month postoperative axial sections of CBCT scans were compared and 100% maxillary alveolar ridge continuity was achieved in both groups. The preoperative and postoperative occlusal photographs of both the groups were compared and showed accurate bone and well aligned maxillary alveolar ridge formation in all patients.

CONCLUSION

The present study concluded that maxillary alveolar ridge formation rate is less in cortico-cancellous iliac crest block graft compared to cancellous iliac crest particulate graft, but is equally good as cancellous bone graft.

CLINICAL TRIAL REGISTRATION NO

(REF/2020/09/031605)/ CTRI/ 2020/09/028001.

Hydroxyapatite-chitosan composites derived from sea cucumbers and shrimp shells ameliorate femoral bone defects in an albino rat model

Background and Aim

A bone defect is defined as a critically sized autologous bone and a bone gap. Bone grafting is one of the most commonly used surgical methods to enhance bone regeneration in orthopedic procedures. A composite of collagen, hydroxyapatite (HA), and chitosan (Ch) is suitable as a bone matrix and stimulates ossification. This study aimed to evaluate the use of natural HA-Ch composites derived from sea cucumbers and shrimp shells and quantify the levels of cytokines, polymorphonuclear neutrophils (PMNs), serum liver enzymes, calcium, phosphate, and procollagen type 1 N-terminal propeptide (PINP) in albino rats with femoral bone defects.

Materials and Methods

A total of 48 albino rats with femoral bone defects were divided into 4 groups (n = 12 each): (C-) placebo, (C+) polyethylene glycol, (T1) HA, and (T2) HA-Ch groups. Each group was divided into two subgroups (n = 6 each), with euthanization on 7- and 42-day post-treatment, respectively. Procollagen Type 1 N-terminal propeptide and the cytokines interleukin (IL)-4, IL-6, IL-10, and tumor necrosis factor-alpha were quantified using enzyme-linked immunosorbent assay. Flow cytometry was performed to evaluate PMNs. A clinical chemistry analyzer was used to measure the serum levels of liver enzymes, calcium, and phosphate.

Results

There was a significant decrease in the level of IL-6 on 7 days and in the level of IL-10 on 42 days in the HA-Ch group. The level of PMNs also decreased significantly on 7 and 42 days in the HA-Ch group. Regarding serum liver enzymes, alkaline phosphatase (ALP) levels in the HA-Ch group increased significantly on 42 days. Calcium and phosphate levels increased significantly on 7 and 42 days in the HA and HA-Ch groups, and PINP levels increased significantly on 7 and 42 days in the HA-Ch group.

Conclusion

The HA-Ch composite derived from sea cucumbers and shrimp shells ameliorated femoral bone defects in albino rats. The HA-Ch composite modulated the levels of IL-6, IL-10, PMNs, ALP, calcium, phosphate, and PINP on 7- and 42-day post-treatment.

Three-dimensional Assessment of Autologous Calvarial Bone Grafting for Alveolar Clefts Reconstruction in Pediatric Population: A Retrospective Study

Reconstruction of alveolar clefts using cancellous bone graft is associated with a high rate of resorption. The aim of this study was to evaluate the osseointegration capacity of cortical calvarial bone grafting using 3-dimensional imaging assessment for alveolar cleft reconstruction in pediatric population.All alveolar bone grafting procedures performed between January 2015 and October 2017 in the maxillofacial surgery department of Lille University Hospital were included. All patients were evaluated clinically and by 3-dimensional imaging before bone grafting and at 3 months after surgery. Cleft and bone graft volumes were assessed using Horos software, v. 3.3.5, through a segmentation process. The bone filled ratio at 3 months after surgery was calculated. A total of 48 alveolar bone grafting procedures were performed in 37 patients: 3 unilateral cleft lip and alveolar, 20 unilateral cleft lip and palate, and 25 bilateral full cleft lip and palate (3 patients had only unilateral surgery). The mean bone filled ratio was 72.27%±23.65%, 81% for unilateral cleft lip and alveolus, 75.4%±20.6 for unilateral cleft lip and palate, and 65.5%±30 for bilateral complete cleft lip and palate ( P =0.1981). Calvarial bone grafting seems to be a relevant alternative to other donor sites for alveolar cleft reconstruction.

Matrix vesicles from dental follicle cells improve alveolar bone regeneration via activation of the PLC/PKC/MAPK pathway

Background

The regeneration of bone loss that occurs after periodontal diseases is a significant challenge in clinical dentistry. Extracellular vesicles (EVs)-based cell-free regenerative therapies represent a promising alternative for traditional treatments. Developmental biology suggests matrix vesicles (MVs), a subtype of EVs, contain mineralizing-related biomolecules and play an important role in osteogenesis. Thus, we explore the therapeutic benefits and expect to find an optimized strategy for MV application.

Methods

Healthy human dental follicle cells (DFCs) were cultured with the osteogenic medium to generate MVs. Media MVs (MMVs) were isolated from culture supernatant, and collagenase-released MVs (CRMVs) were acquired from collagenase-digested cell suspension. We compared the biological features of the two MVs and investigated their induction of cell proliferation, migration, mineralization, and the modulation of osteogenic genes expression. Furthermore, we investigated the long-term regenerative capacity of MMVs and CRMVs in an alveolar bone defect rat model.

Results

We found that both DFC-derived MMVs and CRMVs effectively improved the proliferation, migration, and osteogenic differentiation of DFCs. Notably, CRMVs showed better bone regeneration capabilities. Compared to MMVs, CRMVs-induced DFCs exhibited increased synthesis of osteogenic marker proteins including ALP, OCN, OPN, and MMP-2. In the treatment of murine alveolar bone defects, CRMV-loaded collagen scaffold brought more significant therapeutic outcomes with less unhealing areas and more mature bone tissues in comparison with MMVs and acquired the effects resembling DFCs-based treatment. Furthermore, the western blotting results demonstrated the activation of the PLC/PKC/MAPK pathway in CRMVs-induced DFCs, while this cascade was inhibited by MMVs.

Conclusions

In summary, our findings revealed a novel cell-free regenerative therapy for repairing alveolar bone defects by specific MV subtypes and suggest that PLC/PKC/MAPK pathways contribute to MVs-mediated alveolar bone regeneration.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02721-6.

Maxillofacial morphology in post-pubertal patients with unilateral cleft lip and palate following early vs. late secondary alveolar bone grafting

The study aimed at comparing maxillofacial morphology and burden of surgical treatment in post-pubertal patients with unilateral cleft lip and palate (UCLP) following early vs. late secondary alveolar bone grafting (SABG). In this retrospective study maxillofacial morphology was assessed on lateral cephalograms of skeletally matured patients with UCLP operated on consecutively in one center by the same method of one-stage primary cleft repair followed by SABG. Cephalometric analysis comprised 8 angular and 7 linear measurements. Maxillary growth restriction was evaluated by measuring SNA angle and Co-A and PNS-A distances. Five linear regression models with SNA, SNB, ANB, Co-A, and MP/SN as dependent variables and age at primary cleft repair, age at SABG, age at taking cephalogram, surgeon, and total number of surgical interventions as independent variables were also created. 135 patients were included in the study - 70 patients (47 males and 23 females) had early SABG (E-SABG group) and 65 patients (40 males and 25 females) had late SABG (L-SABG group). Mean age at bone grafting procedure was 2.7 years (range 1.5-5.9, SD 1.1) and 10.3 years (range 6.1-18.8, SD 3.2) in E-SABG and LSABG group respectively. The variables describing the degree of maxillary growth restriction - SNA, Co-A, and PNS-A - were comparable in both groups (p = 0.707, 0.116, and 0.932, respectively). Regression models demonstrated that independent variables were not associated with the values of SNA angle, SNB angle, ANB angle, MP/SN angle, and Co-A distance (p = 0.761, 0.088, 0.249, 0.380, and 0.363, respectively). The percentages of oronasal fistula repair, VPI repair, repeated SABG, upper lip correction, rhinoplasty, orthognathic surgery were 22.9, 7.1, 15.7, 24.3, 42.9, 2.9 in E-SABG group and 27.7, 7.7, 9.2, 36.9, 47.7, 3.1 in L-SABG group respectively. Mean number of all surgical interventions was 3.2 in E-SABG and 3.4 in L-SABG group, respectively (p = 0.271). Considering the comparable maxillofacial morphology and burden of surgical care in matured patients after early and late SABG, the choice of timing of bone grafting surgery could be left to the discretion of the surgeon.

Cleft Alveolar Bone Graft Materials: Literature Review

INTRODUCTION

Since the early stages of alveolar bone grafting development, multiple types of materials have been used. Iliac cancellous bone graft (ICBG) remains the gold standard.

DESIGN/METHODS

A review of literature is conducted in order to describe the different bone filling possibilities, autologous or not, and to assess their effectiveness compared to ICBG. This review focused on studies reporting volumetric assessment of the alveolar cleft graft result (by computed tomography scan or cone beam computed tomography).

RESULTS

Grafting materials fall into 3 types: autologous bone grafts, ICBG supplementary material, and bone substitutes. Among autologous materials, no study showed the superiority of any other bone origin over iliac cancellous bone. Yet ICBG gives inconsistent results and presents donor site morbidity. Concerning supplementary material, only 3 studies could show a benefit of adding platelet-rich fibrin (1 study) or platelet-rich plasma (2 studies) to ICBG, which remains controversial in most studies. There is a lack of 3-dimensional (3D) assessment in most articles concerning the use of scaffolds. Only one study showed graft improvement when adding acellular dermal matrix to ICBG. Looking at bone substitutes highlights failures among bioceramics alone, side-effects with bone morphogenetic protein-2 composite materials, and difficulties in cell therapy setup. Studies assessing cell therapy-based substitutes show comparable efficacy with ICBG but remain too few.

CONCLUSION

This review highlights the lack of 3D assessments in the alveolar bone graft materials field. Nothing dethroned ICBG from its position as the gold standard treatment at this time.

A Review of the Functions of Matrix Vesicles in Periodontal Tissues

Periodontal tissues consist of cementum, periodontal ligaments, and alveolar bone, which provide indispensable support for physiological activities involving mastication, swallowing, and pronunciation. The formation of periodontal tissues requires a complex process, during which a close relationship with biomineralization is noticeable. Alveolar bone and cementum are physically hard, both of which are generated from biomineralization and possess the exact mechanical properties resembling other hard tissues. However, when periodontitis, congenital abnormalities, periapical diseases, and other pathological conditions affect the organism, the most common symptom, alveolar bone defect, is always unavoidable, which results in difficulties for current clinical treatment. Thus, exploring effective therapies to improve the prognosis is important. Matrix vesicles (MVs), a special subtype of extracellular vesicles related to histogenesis, are widely produced by the stem cells of developing hard tissues. With the assistance of the enzymes and transporters contained within them, MVs can construct the extracellular matrix and an adequate microenvironment, thus promoting biomineralization and periodontal development. Presently, MVs can be effectively extracted and delivered by scaffolds and generate hard tissues in vitro and in vivo, which are expected to be translated into therapies for alveolar bone defects. In this review, we generalize recent research progress on MV morphology, molecular composition, biological mechanism, and, in particular, the biological functions in periodontal development. In addition to the above unique roles of MVs, we further describe the available MV-related biotechnologies and achievements that make them promising for coping with existing problems and improving the treatment of alveolar bone defects.