Dental materials for cleft palate repair

Stem Cell-Based Tissue Engineering for Cleft Defects: Systematic Review and Meta-Analysis

This study aimed to analyze the efficacy of stem cell-based tissue engineering for the treatment of alveolar cleft (AC) and cleft palate (CP) defects in animal models.

Systematic review and meta-analysis.

Preclinical studies on alveolar cleft repair in maxillofacial practice.

Electronic search was performed using PubMed, Embase, and Cochrane databases. Pre-clinical studies, where stem cell-based tissue engineering was used in the reconstruction of AC and CP in animal models were included. Quality of the selected articles was evaluated using SYRCLE (SYstematic Review Centre for Laboratory animal Experimentation).

Review of alveolar cleft bone augmentation interventions in preclinical models.

Outcome parameters registered were new bone formation (NBF) and/or bone mineral density (BMD).

Thirteen large and twelve small animal studies on AC (21) and CP (4) reconstructions were included. Studies had an unclear-to-high risk of bias. Bone marrow mesenchymal stem cells were the most widely used cell source. Meta-analyses for AC indicated non-significant benefits in favor of: (1) scaffold + cells over scaffold-only (NBF P = .13); and (2) scaffold + cells over empty control (NBF P = .66; BMD P = .31). Interestingly, dog studies using regenerative grafts showed similar to superior bone formation compared to autografts. Meta analysis for the CP group was not possible.

AC and CP reconstructions are enhanced by addition of osteogenic cells to biomaterials. Directions and estimates of treatment effect are useful to predict therapeutic efficacy and guide future clinical trials of bone tissue engineering.

Stem Cell-Based Regenerative Approaches for the Treatment of Cleft Lip and Palate: A Comprehensive Review

Cleft lip and/or palate (CLP) is a prevalent congenital craniofacial abnormality that can lead to difficulties in eating, speaking, hearing, and psychological distress. The traditional approach for treating CLP involves bone graft surgery, which has limitations, post-surgical complications, and donor site morbidity. However, regenerative medicine has emerged as a promising alternative, employing a combination of stem cells, growth factors, and scaffolds to promote tissue regeneration. This review aims to provide a comprehensive overview of stem cell-based regenerative approaches in the management of CLP. A thorough search was conducted in the Medline/PubMed and Scopus databases, including cohort studies, randomized controlled trials, case series, case controls, case reports, and animal studies. The identified studies were categorized into two main groups: clinical studies involving human subjects and in vivo studies using animal models. While there are only a limited number of studies investigating the combined use of stem cells and scaffolds for CLP treatment, they have shown promising results. Various types of stem cells have been utilized in conjunction with scaffolds. Importantly, regenerative methods have been successfully applied to patients across a broad range of age groups. The collective findings derived from the reviewed studies consistently support the notion that regenerative medicine holds potential advantages over conventional bone grafting and represents a promising therapeutic option for CLP. However, future well-designed clinical trials, encompassing diverse combinations of stem cells and scaffolds, are warranted to establish the clinical efficacy of these interventions with a larger number of patients.

Correlations between radiological and histological findings of bone remodelling and root resorption in a rodent cleft model

Background

The evaluation of bone remodelling and dental root resorption can be performed by histological techniques or micro-computed tomography (micro-CT). The present study aimed to evaluate the relationship between these two procedures in the context of cleft repair in a rat model.

Methods

The reconstructed maxillae and the orthodontically-moved first molar of 12 rats were analysed for correlations between the histological and radiological findings retrospectively. The alveolar cleft repairs were performed using bone autografts or (human) xenografts. Four weeks after the operation, the intervention of the first molar protraction was initiated and lasted for eight weeks. The newly formed bone and the root resorption lacunae were determined via histology. In the micro-CT analysis, the average change of bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness and trabecular separation of the jaw, as well as the volume of the root resorptions were determined. The Pearson correlation coefficient was applied to study the associations between groups.

Results

Positive correlations were found only between the newly formed bone (histology) and BMD changes (micro-CT) in the autograft group (r = 0.812, 95% CI: 0.001 to 0.979, p = 0.05). The relationship of newly formed bone and BV/TV was similar but not statistically significant (r = 0.691, 95% CI: −0.274 to 0.963, p = 0.013). Regarding root resorption, no significant correlations were found.

Conclusions

Due to the lack of correlation between histological and radiological findings of bone remodelling and the development of root resorptions, both methods should be combined in this cleft model in rats for a comprehensive analysis.

Alveolar cleft bone grafting at different age periods

Relevance. Anatomical and functional disorders in congenital clefts may be various. Their severity depends on the cleft size and on the combination of a cleft lip with an alveolar cleft. Alveolar cleft bone grafting (ACBG) is one of the most important surgeries for patients with cleft lip and palate rehabilitation. The study aimed to analyze the results of alveolar cleft bone grafting in various age groups, summarizing the available data and supplementing them with our own experience.

Materials and methods. In our clinic, 488 patients of different ages (from 4 to 18 years old), including patients with bilateral clefts, underwent ACBG.

Results. The result analysis showed the time of surgery should depend not on the child's age but on the orthodontic preparation of the child for ACBG.

Conclusion. The literature data and our experience allowed us to develop indications for ACBG at different ages

The strategy of composite grafting with BMP2-Loaded calcium phosphate cements and autogenous bone for alveolar cleft reconstruction

Purpose: To remedy the drawbacks of traditional autogenous bone harvesting in alveolar bone grafting (ABG), a novel strategy of composite grafting with BMP2-loaded calcium phosphate cements (BMP2-CPC) and autogenous bone harvested by minimally invasive technique was developed and evaluated for its bone-repairing efficacy.

Materials and methods: A chart review was conducted for 19 patients with unilateral alveolar clefts who underwent secondary ABG from 2017 to 2020. Of the enrolled patients, 9 patients underwent grafting with autogenous bone harvested by traditional trap door technique (group I), and 10 patients underwent grafting with the composite graft comprising BMP2-CPC and autogenous bone harvested by minimally invasive technique at a ratio of 1:1 by volume (group II). The clinical performance of the composite graft was comprehensively evaluated in terms of clinical, radiographic and histological perspectives.

Results: The present results demonstrated that the composite graft exhibited satisfactory bone-repairing efficacy comparable to that of the autogenous bone graft on the premise of lower amount of harvested bone. The post-surgical resorption of bone volume and vertical height of grafted area was significantly slower in group II. The favourable resorption performance of BMP2-CPC contributed to preserving the post-surgical bony contour reconstructed with the composite graft.

Conclusion: The composite graft comprising BMP2-CPC and autogenous bone harvested by minimally invasive technique was demonstrated to be an eligible alternative for application in ABG, especially for its improved resorption performance in preserving post-surgical bony contour.

Effect of Hydroxyapatite Coating by Er: YAG Pulsed Laser Deposition on the Bone Formation Efficacy by Polycaprolactone Porous Scaffold

Composite scaffolds obtained by the combination of biodegradable porous scaffolds and hydroxyapatite with bone regeneration potential are feasible materials for bone tissue engineering. However, most composite scaffolds have been fabricated by complicated procedures or under thermally harsh conditions. We have previously demonstrated that hydroxyapatite coating onto various substrates under a thermally mild condition was achieved by erbium-doped yttrium aluminum garnet (Er: YAG) pulsed laser deposition (PLD). The purpose of this study was to prepare a polycaprolactone (PCL) porous scaffold coated with the hydroxyapatite by the Er: YAG-PLD method. Hydroxyapatite coating by the Er: YAG-PLD method was confirmed by morphology, crystallographic analysis, and surface chemical characterization studies. When cultured on PCL porous scaffold coated with hydroxyapatite, rat bone marrow-derived mesenchymal stem cells adhered, spread, and proliferated well. The micro-CT and staining analyses after the implantation of scaffold into the critical-sized calvaria bone defect in rats indicate that PCL porous scaffold coated with hydroxyapatite demonstrates accelerated and widespread bone formation. In conclusion, PCL porous scaffold coated with hydroxyapatite obtained by the Er: YAG-PLD method is a promising material in bone tissue engineering.

Impact of Frontier Development of Alveolar Bone Grafting on Orthodontic Tooth Movement

Sufficient alveolar bone is a safeguard for achieving desired outcomes in orthodontic treatment. Moving a tooth into an alveolar bony defect may result in a periodontal defect or worse–tooth loss. Therefore, when facing a pathologic situation such as periodontal bone loss, alveolar clefts, long-term tooth loss, trauma, and thin phenotype, bone grafting is often necessary to augment bone for orthodontic treatment purposes. Currently, diverse bone grafts are used in clinical practice, but no single grafting material shows absolutely superior results over the others. All available materials demonstrate pros and cons, most notably donor morbidity and adverse effects on orthodontic treatment. Here, we review newly developed graft materials that are still in the pre-clinical stage, as well as new combinations of existing materials, by highlighting their effects on alveolar bone regeneration and orthodontic tooth movement. In addition, novel manufacturing techniques, such as bioprinting, will be discussed. This mini-review article will provide state-of-the-art information to assist clinicians in selecting grafting material(s) that enhance alveolar bone augmentation while avoiding unfavorable side effects during orthodontic treatment.

Development of root resorption during orthodontic tooth movement after cleft repair using different grafting materials in rats

OBJECTIVE

The aim of the present study was to investigate the influence of three grafting materials for cleft repair on orthodontic tooth movement in rats.

MATERIALS AND METHODS

Artificial alveolar clefts were created in 21 Wistar rats and were repaired 4 weeks later using autografts, human xenografts and synthetic bone substitute (beta-tricalcium phosphate/hydroxyapatite [β-TCP/HA]). A further 4 weeks later, the first molar was moved into the reconstructed maxilla. Microfocus computed tomography (μCT) was performed six times (T0-T5) to assess the tooth movement and root resorption. After 8 weeks, the affected reconstructed jaw was resected for histopathological investigation.

RESULTS

Total distances reached ranged from 0.82 ± 0.72 mm (β-TCP/HA) to 0.67 ± 0.27 mm (autograft). The resorption was particularly determined at the mesiobuccal root. Descriptive tooth movement slowed and root resorption increased slightly. However, neither the radiological changes during tooth movement (µCT T1 vs. µCT T5: autograft 1.85 ± 0.39 mm³ vs. 2.38 ± 0.35 mm³, p = 0.30; human xenograft 1.75 ± 0.45 mm³ vs. 2.17 ± 0.26 mm³, p = 0.54; β-TCP/HA: 1.52 ± 0.42 mm³ vs. 1.88 ± 0.41 mm³, p = 0.60) nor the histological differences after tooth movement (human xenograft: 0.078 ± 0.05 mm²; β-TCP/HA: 0.067 ± 0.049 mm²; autograft: 0.048 ± 0.015 mm²) were statistically significant.

CONCLUSION

The autografts, human xenografts or synthetic bone substitute used for cleft repair seem to have a similar effect on the subsequent orthodontic tooth movement and the associated root resorptions.

CLINICAL RELEVANCE

Development of root resorptions seems to have a secondary role in choosing a suitable grafting material for cleft repair.

3D Printing of Tricalcium Phosphate/Poly Lactic-co-glycolic Acid Scaffolds Loaded with Carfilzomib for Treating Critical-sized Rabbit Radial Bone Defects

The rapid development of scaffold-based bone tissue engineering strongly relies on the fabrication of advanced scaffolds and the use of newly discovered functional drugs. As the creation of new drugs and their clinical approval often cost a long time and billions of U.S. dollars, producing scaffolds loaded with repositioned conventional drugs whose biosafety has been verified clinically to treat critical-sized bone defect has gained increasing attention. Carfilzomib (CFZ), an approved clinical proteasome inhibitor with a much fewer side effects, is used to replace bortezomib to treat multiple myeloma. It is also reported that CFZ could enhance the activity of alkaline phosphatase and increase the expression of osteogenic transcription factors. With the above consideration, in this study, a porous CFZ/β-tricalcium phosphate/poly lactic-co-glycolic acid scaffold (designated as “cytidine triphosphate [CTP]”) was produced through cryogenic three-dimensional (3D) printing. The hierarchically porous CTP scaffolds were mechanically similar to human cancellous bone and can provide a sustained CFZ release. The implantation of CTP scaffolds into critical-sized rabbit radius bone defects improved the growth of new blood vessels and significantly promoted new bone formation. To the best of our knowledge, this is the first work that shows that CFZ-loaded scaffolds could treat nonunion of bone defect by promoting osteogenesis and angiogenesis while inhibiting osteoclastogenesis, through the activation of the Wnt/β-catenin signaling. Our results suggest that the loading of repositioned drugs with effective osteogenesis capability in advanced bone tissue engineering scaffold is a promising way to treat critical-sized defects of a long bone.

The Challenge of 3D Bioprinting of Composite Natural Polymers PLA/Bioglass: Trends and Benefits in Cleft Palate Surgery

Cleft lip and palate is the fourth most common congenital malformation. Its prevalence is about 1 in 750 to 1 in 2000 live births. The consequences of this malformation are major: maxillary growth deficit, unaesthetic appearance, phonation disorders, difficulty in eating, and psycho-social disorders. Cleft palate repair establishes the division between the oral and nasal cavities. The alveolar bone graft is a key step. Different sites of autogenous bone harvesting are used, the most common being the iliac crest. Nevertheless, the large number of complications associated with harvesting has led to the use of substitute biomaterials. Bioactive glasses, discovered in 1969, are a group of synthetic silica-based materials with bone-bonding properties. Although 45S5 granular composition is commonly used in bone surgery to repair critical defects, it is only rarely used in the repair of cleft palates because this galenic form is only moderately adapted. However, advances in bone tissue engineering allow the shaping of three-dimensional scaffolds, which support colonization by host cells. Recent advances in computer-aided design/computer-aided manufacturing (CAD/CAM) have even led to the 3D printing of scaffolds combining 45S5 bioglass with a natural and biocompatible poly-lactic acid matrix. The shape of the parts is customized and adapted to the particular shape of the critical bone defects. The objective of this literature review is to highlight the particularities of alveolar defects subsequent to facial clefts, then to detail the characteristics of the materials and technologies used to elaborate 3D matrices by bioprinting. Finally, we will explore research directions regarding their use in reconstructive surgery of cleft palates.

Evaluation of different grafting materials for alveolar cleft repair in the context of orthodontic tooth movement in rats

To minimize the postoperative risks posed by grafting autologous transplants for cleft repair, efforts are being made to improve grafting materials for use as potential alternatives. The aim of this study was to compare the bone graft quality of different bone substitutes including the gold standard autografts during the healing processes after cleft repair in the context of orthodontic treatment. In 21 Wistar rats, a complete, continuity-interrupting cleft was created. After 4 weeks, cleft repair was performed using autografts from the hips’ ischial tuberosity, human xenografts, or synthetic bone substitutes [beta-tricalcium phosphate (β-TCP)/hydroxyapatite (HA)]. After another 4 weeks, the first molar movement was initiated in the reconstructed jaw for 8 weeks. The bone remodeling was analyzed in vivo using micro-computed tomography (bone mineral density and bone volume fraction) and histology (new bone formation). All the grafting materials were statistically different in bone morphology, which changed during the treatment period. The β-TCP/HA substitute demonstrated less resorption compared to the autologous and xenogeneic/human bone, and the autografts led to a stronger reaction in the surrounding bone. Histologically, the highest level of new bone formation was found in the human xenografts, and the lowest was found in the β-TCP/HA substitute. The differences between the two bone groups and the synthetic materials were statistically significant. Autografts were confirmed to be the gold standard in cleft repair with regard to graft integration. However, parts of the human xenograft seemed comparable to the autografts. Thus, this substitute could perhaps be used as an alternative after additional tissue-engineered modification.

Establishing a new alveolar cleft model in rats to investigate the influence of jaw reconstructions on orthodontic tooth movement

BACKGROUND

The aim of the present investigation was to develop a new cleft model in rats that allows alveolar cleft repair and subsequent tooth movement.

METHODS

A complete continuity-interrupting alveolar cleft was performed on the left-side maxillae of 33 rats through ultrasonic surgery. The clefts were filled with bone wax, and microCT scans were done to analyze the cleft size. After four weeks, the cleft repair was completed using autologous, xenogeneic (human), or synthetic bone substitute. After an additional four weeks, the orthodontic tooth movement was initiated.

RESULTS

Fourteen rats died during the research, and the study design was constantly adapted accordingly. The main reasons for death included breathing problems during or immediately after the experimental activities (eight animals), followed by two deaths due to circulatory failures. In the remaining 19 animals, the average cleft size was about 2.70 ± 0.46 × 2.01 ± 0.25 × 1.18 ± 0.20 mm, and the mean velocity of orthodontic tooth movement after seven days was between 0.21 ± 0.08 mm in the autologous group and 0.50 ± 0.54 mm in the xenogeneic group. After 56 days, the mean values ranged between 0.67 ± 0.27 mm in the autologous group and 0.82 ± 0.72 mm in the synthetic group.

CONCLUSIONS

Surgical interventions in the oral cavity of rats requires a stronger anesthesia and lead to increased risk of coolant and coagulated blood aspiration. The new alveolar cleft model in rats allows for subsequent orthodontic tooth movement after cleft repair, but only in the mesial root of the first molar.

Desktop-Stereolithography 3D Printing of a Polyporous Extracellular Matrix Bioink for Bone Defect Regeneration

Introduction

Decellularized tendon extracellular matrix (tECM) perfectly provides the natural environment and holds great potential for bone regeneration in Bone tissue engineering (BTE) area. However, its densifying fiber structure leads to reduced cell permeability. Our study aimed to combine tECM with polyethylene glycol diacrylate (PEGDA) to form a biological scaffold with appropriate porosity and strength using stereolithography (SLA) technology for bone defect repair.

Methods

The tECM was produced and evaluated. Mesenchymal stem cell (MSC) was used to evaluate the biocompatibility of PEGDA/tECM bioink in vitro. Mineralization ability of the bioink was also evaluated in vitro. After preparing 3D printed polyporous PEGDA/tECM scaffolds (3D-pPES) via SLA, the calvarial defect generation capacity of 3D-pPES was assessed.

Results

The tECM was obtained and the decellularized effect was confirmed. The tECM increased the swelling ratio and porosity of PEGDA bioink, both cellular proliferation and biomineralization in vitro of the bioink were significantly optimized. The 3D-pPES was fabricated. Compared to the control group, increased cell migration efficiency, up-regulation of osteogenic differentiation RNA level, and better calvarial defect repair in rat of the 3D-pPES group were observed.

Conclusion

This study demonstrates that the 3D-pPES may be a promising strategy for bone defect treatment.

Ischial tuberosity: new donor site for bone grafts in animal cleft research

In the context of cleft repair in animal research in rat models, different areas can be used for bone grafting. The aim of the present study was to present the tuberosity of the ischium as a new donor site and to evaluate its quality in relation to an artificial alveolar cleft. Four weeks after creating experimental alveolar clefts in seven Wistar rats, the repair was performed in the now twelve-week-old male animals using bone blocks grafted from the ischial tuberosity. Two days before surgery and two as well as twenty-eight days after surgery, microCT scans were performed, and the grafted bone blocks were analyzed regarding height, width, thickness, and volume. Additionally, bone mineral density (BMD) and bone volume fraction (BV/TV) were measured in the repaired cleft. The mean bone volume of the graft was about 19.77 ± 7.77mm³. Immediately after jaw reconstruction the BMD and BV/TV were about 0.54 ± 0.05 g/cm³ and 54.9 ± 5.07% for the transplant and about 1.13 ± 0.08 g/cm³ and 94.5 ± 3.70%, respectively, for the surrounding bone. Four weeks later the BMD and BV/TV were about 0.57 ± 0.13 g/cm³ and 56.60 ± 13.70% for the transplant and about 11.17 ± 0.07 g/cm³ and 97.50 ± 2.15%, respectively, for the surrounding bone. A hip fracture was found in four of the animals after surgery. The ischial tuberosity offers large bone blocks, which are sufficient for cleft repair in the rat model. However, the bone quality regarding BMD and BV/TV is less compared with the surrounding bone of the alveolar cleft, even after a period of 4 weeks, despite recognizable renovation processes.

Innovative Molecular and Cellular Therapeutics in Cleft Palate Tissue Engineering

Clefts of the lip and/or palate are the most prevalent orofacial birth defects occurring in about 1:700 live human births worldwide. Early postnatal surgical interventions are extensive and staged to bring about optimal growth and fusion of palatal shelves. Severe cleft defects pose a challenge to correct with surgery alone, resulting in complications and sequelae requiring life-long, multidisciplinary care. Advances made in materials science innovation, including scaffold-based delivery systems for precision tissue engineering, now offer new avenues for stimulating bone formation at the site of surgical correction for palatal clefts. In this study, we review the present scientific literature on key developmental events that can go awry in palate development and the common surgical practices and challenges faced in correcting cleft defects. How key osteoinductive pathways implicated in palatogenesis inform the design and optimization of constructs for cleft palate correction is discussed within the context of translation to humans. Finally, we highlight new osteogenic agents and innovative delivery systems with the potential to be adopted in engineering-based therapeutic approaches for the correction of palatal defects. Impact statement Tissue-engineered scaffolds supplemented with osteogenic growth factors have attractive, largely unexplored possibilities to modulate molecular signaling networks relevant to driving palatogenesis in the context of congenital anomalies (e.g., cleft palate). Constructs that address this need may obviate current use of autologous bone grafts, thereby avoiding donor-site morbidity and other regenerative challenges in patients afflicted with palatal clefts. Combinations of biomaterials and drug delivery of diverse regenerative cues and biologics are currently transforming strategies exploited by engineers, scientists, and clinicians for palatal cleft repair.

Evaluation of density, volume, height and rate of bone resorption of substitutes of autologous bone grafts for the repair of alveolar clefts in humans: A systematic review

Objective

To assess clinical studies that compare synthetic or enriched natural materials to autologous osseous grafts among individuals with cleft lip and palate to determine which would be the substitute to autologous bone graft for alveolar cleft repair in humans.

Materials and methods

Randomized and controlled clinical trials on alveolar clefts treated with synthetic bone substitutes and autogenous bone grafts combined with osteoinductive factors compared with autogenous bone grafts alone (with ≥4-month follow-up and reporting clinical/radiographic data) were considered eligible. MEDLINE, EMBASE, and Central databases were searched for articles published until February 2020.

Results

Of 73 eligible articles, 15 were included. Some inductive factors along with iliac crest bone decreased bone reabsorption, preserved the generated bone height/width, and reduced the required autologous bone graft volume. Bone morphogenetic protein (BMP2) as an autologous bone graft substitute, demonstrated satisfactory alveolar defect healing, by avoiding autograft use. Many materials did not yield better outcomes than did autologous grafts; however, hydroxyapatite and collagen complex, hydroxyapatite agarose composite gel, acellular dermal matrix film, fibrin glue, platelet-rich plasma, and deproteinized bovine bone showed similar bone healing outcomes, being an alternative alveolar defect treatment.

Conclusions

BMP2, as an osteoinductive factor along with a synthetic matrix, yields satisfactory bone healing and avoids the need for autologous bone grafts. However, high-quality RCTs are necessary to determine the most effective and safe concentration and protocol of BMP2 utilization as a substitute for the autologous iliac crest bone grafting.

Extracellular Matrix Composition and Remodeling: Current Perspectives on Secondary Palate Formation, Cleft Lip/Palate, and Palatal Reconstruction

Craniofacial development comprises a complex process in humans in which failures or disturbances frequently lead to congenital anomalies. Cleft lip with/without palate (CL/P) is a common congenital anomaly that occurs due to variations in craniofacial development genes, and may occur as part of a syndrome, or more commonly in isolated forms (non-syndromic). The etiology of CL/P is multifactorial with genes, environmental factors, and their potential interactions contributing to the condition. Rehabilitation of CL/P patients requires a multidisciplinary team to perform the multiple surgical, dental, and psychological interventions required throughout the patient's life. Despite progress, lip/palatal reconstruction is still a major treatment challenge. Genetic mutations and polymorphisms in several genes, including extracellular matrix (ECM) genes, soluble factors, and enzymes responsible for ECM remodeling (e.g., metalloproteinases), have been suggested to play a role in the etiology of CL/P; hence, these may be considered likely targets for the development of new preventive and/or therapeutic strategies. In this context, investigations are being conducted on new therapeutic approaches based on tissue bioengineering, associating stem cells with biomaterials, signaling molecules, and innovative technologies. In this review, we discuss the role of genes involved in ECM composition and remodeling during secondary palate formation and pathogenesis and genetic etiology of CL/P. We also discuss potential therapeutic approaches using bioactive molecules and principles of tissue bioengineering for state-of-the-art CL/P repair and palatal reconstruction.

Balancing Purification and Ultrastructure of Naturally Derived Bone Blocks for Bone Regeneration: Report of the Purification Effort of Two Bone Blocks

The present publication reports the purification effort of two natural bone blocks, that is, an allogeneic bone block (maxgraft^®, botiss biomaterials GmbH, Zossen, Germany) and a xenogeneic block (SMARTBONE^®, IBI S.A., Mezzovico-Vira, Switzerland) in addition to previously published results based on histology. Furthermore, specialized scanning electron microscopy (SEM) and in vitro analyses (XTT, BrdU, LDH) for testing of the cytocompatibility based on ISO 10993-5/-12 have been conducted. The microscopic analyses showed that both bone blocks possess a trabecular structure with a lamellar subarrangement. In the case of the xenogeneic bone block, only minor remnants of collagenous structures were found, while in contrast high amounts of collagen were found associated with the allogeneic bone matrix. Furthermore, only island-like remnants of the polymer coating in case of the xenogeneic bone substitute seemed to be detectable. Finally, no remaining cells or cellular remnants were found in both bone blocks. The in vitro analyses showed that both bone blocks are biocompatible. Altogether, the purification level of both bone blocks seems to be favorable for bone tissue regeneration without the risk for inflammatory responses or graft rejection. Moreover, the analysis of the maxgraft^® bone block showed that the underlying purification process allows for preserving not only the calcified bone matrix but also high amounts of the intertrabecular collagen matrix.

Volumetric comparison of autogenous bone and tissue-engineered bone replacement materials in alveolar cleft repair: a systematic review and meta-analysis

The goal of reconstruction of the alveolar cleft in patients with cleft lip and palate is to improve the quality of tissue, the structural stability, and increase the volume of bone. This study is a systematic review with meta-analysis of volumetric bony filling using autogenous bone and various tissue-engineered bone substitutes. We made an electronic search on MEDLINE, EMBASE, SCOPUS, WEB OF SCIENCE, "grey" publications (materials and research produced by organisations outside traditional channels for commercial or academic publishing and distribution), and relevant cross references according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies that reported the outcomes of volumetric grafting were included in the meta-analysis. Of 1276 studies, 26 were included in the meta-analysis. Pooled analysis of 25 studies that used autogenous bone showed a significant reduction in the volume of the cleft equivalent to 62.0% bone fill (95% CI 54.3 to 69.6), in contrast to 10 studies that used a tissue-engineered material and reported bone filling of 68.7% (95% CI 54.5 to 82.8). The estimated sizes of pooled effects across studies showed that there was no significant difference between the two major intervention groups (p value 0.901). Our statistical analysis showed that autogenous bone grafts did not differ significantly from tissue-engineered materials in their ability to fill clefts. Systematic review registration: International Prospective Register of Systematic Reviews, PROSPERO (CRD42017065045).

Three-dimensional Printing in Maxillofacial Surgery: Hype versus Reality

Three-dimensional printing technology is getting more attention recently, especially in the craniofacial region. This is a review of literature enlightening the materials that have been used to date and the application of such technology within the scope of maxillofacial surgery.

Clinical survey over the past 35 years at the clinic for maxillofacial prosthetics Tokyo Medical and Dental University

PURPOSE

The purpose of this survey was to examine the overview of maxillofacial prosthetic treatment at our department, in order to ascertain the actual status of patients and discuss future needs.

METHODS

Subjects were all patients who visited Clinic for Maxillofacial Prosthetics, Dental Hospital, Tokyo Medical and Dental University (TMDU) in the period from January 1, 1980 to December 31, 2014. Using medical records of the Clinic for Maxillofacial Prosthetics, Dental Hospital, TMDU, patients' data including sex, address, referring institution, and primary condition were analyzed throughout the period.

RESULTS

The number of patients over 35 years was 6219, with a man-to-woman ratio of 6:4. The number of patients in their 60s, 70s, and 80s showed an increasing trend. Patients with tumors accounted for about 50 % of cases in 1980-1984 and increased to 80 % in 2010-2014.

CONCLUSIONS

The survey showed an increasing number of elderly patients and patients with tumors. This suggests that more awareness and education about maxillofacial prosthetics are needed.