HGF/MET in osteogenic differentiation of primary human palatal periosteum-derived mesenchymal stem cells.

PURPOSE: This study aimed to determine expressions of hepatocyte growth factor (HGF) and MET proto-oncogene receptor tyrosine kinase (MET) in palatal periosteum (PP) and to examine the effect of HGF/MET on osteogenic differentiation of human palatal periosteum-derived mesenchymal stem cells (PD-MSCs). METHODS: HGF/MET proteins in human palatal periosteum (n = 3) were localized using immunohistochemistry. PD-MSCs (n = 3) were cultured in serum-free Essential 8 (E8) medium or osteogenic medium with and without Capmatinib, a selective ATP-inhibitor of MET. HGF concentration in vitro was measured with ELISA. Relative gene expression was quantified from PD-MSCs by quantitative reverse transcription real-time polymerase chain reaction. RESULTS: Immunohistochemistry detected co-localization of HGF and MET protein in PP. HGF protein levels were significantly higher (P < 0.05) in osteogenic media (day 21: 12.19 ± 8.36 ng/mL) than in E8 medium (day 21: 0.42 ± 0.72 ng/mL). MET inhibitor had a limited feedback effect on the expression profile of the osteogenic genes tested. Gene expression levels for all but three genes were comparable in serum-free and osteogenic media at all time points. CONCLUSION: HGF/MET present in human PP and HGF is upregulated in vitro during osteogenesis; however the targeted pathways controlled by MET may not involve osteoblast maturation.

Resorbable Versus Nonresorbable Membranes: When and Why?

Guided bone-regeneration techniques use either resorbable or nonresorbable membrane. Ideal membrane material should be biocompatible with tissue integration, be able to create and maintain space, be occlusive with selective permeability, and have good handling properties. Commercially available nonresorbable membranes are Gor-tex (e-PTFE), Cytoplast (d-PTFE), and titanium mesh. Resorbable membranes are available as natural and synthetic. Clinical trials, a systematic review and meta-analysis have shown no statistically significant difference in most clinical indications between both types of membrane. The choice of membrane varies according to the choice of grafting materials and nature of defect.

Tissue Engineering: What is New?

Soft and hard tissue engineering has expanded the frontiers of oral/maxillofacial augmentation. Soft tissue grafting enhancements include improving flap prevascularization and using stem cells and other cells to create not only the graft, but also the vascularization and soft tissue scaffolding for the graft. Hard tissue grafts have been enhanced by osteoinductive factors, such as bone morphogenic proteins, that have allowed the elimination of harvesting autogenous bone and thus decrease the need for other surgical sites. Advancements in bone graft scaffolds have developed via seeding with stem cells and improvement of the silica/calcium/phosphate composite to improve graft characteristics and healing.

A Straightforward Technique to Repair a Residual Oronasal Fistula in Bilateral Cleft Lip and Palate Patients.

PURPOSE: An anterior palatal oronasal fistula in a bilateral cleft lip and palate is a challenging clinical dilemma. The purpose of this article is to present a 2-stage technique to repair the fistula in consistent fashion. The technique was developed to avoid more complicated procedures that had greater morbidity for larger oronasal defects that could not be treated in a single procedure. MATERIALS AND METHODS: This is a retrospective study performed over 15 years using this technique in a private practice setting. From 2002 to 2017, 15 7- to 12-year-old patients (11 boys and 4 girls) were treated. They were seen in a multispecialty clinic for anterior residual fistulae, and impressions were obtained. Then, they were scheduled for first-stage closing of the fistulae. Data were retrospectively analyzed. The first stage started with closing the central portion of the fistulae. For the second stage 6 months later, the residual nasoalveolar cleft was closed and grafted in standard fashion. The first stage involved posteriorly reflecting a full-thickness mucoperiosteal flap and inserting it into the palatal soft tissue and stabilizing the segment with a splint for 3 weeks. The premaxillary segment was left denuded. RESULTS: Fourteen of 15 patients (93%) had the central portion of the oronasal fistulae successfully closed. One patient had partial breakdown when the splint was prematurely removed at 2 weeks. The patient underwent successful closure by the same procedure at a later date. All patients had successful second-stage grafting of their nasoalveolar clefts. CONCLUSIONS: An alternative technique is presented to treat clinically challenging oronasal fistulae. This 2-stage closure of a palatal fistula is straightforward, allows consistent closure of soft tissue defects, and avoids complex alternative procedures with serious surgical morbidities.

Localization and characterization of human palatal periosteum stem cells in serum-free, xeno-free medium for clinical use.

Harvesting, expanding, and re-implanting osteogenic mesenchymal stem cells (MSCs) avoids the donor-site morbidity associated with autogenous grafting from bone marrow. Mesenchymal stem cells sourced from the palatal periosteum could be an alternative to isolation of such cells using bone marrow aspiration procedures. For safe use in human therapy, MSCs should be expanded in culture medium that is free from animal or human-derived serum. In this study we localized, quantified, and characterized MSCs from palatal periosteum cultured in serum-free, xeno-free Essential 8 medium. A portion of the palatal periosteum tissues from three patients were dual-immunostained with MSC-specific markers (CD105, CD90, and CD73). The remaining portions were expanded in culture, and the isolated MSCs were analyzed using flow cytometry and tri-lineage differentiation. Palatal periosteum sections were found to contain CD105-, CD90-, and CD73-positive cells. The cultured cells were 73.0 ± 6.7% (mean ± SD) positive for all three MSC-specific markers and were without hematopoietic stem cell (HSC) markers 0.5 ± 0.3% (mean ± SD). Tri-lineage differentiation analysis confirmed that palatal periosteum cells could become adipoblasts, chondroblasts, and osteoblasts. The results demonstrate that palatal-derived MSCs could be detected in situ within small niches, and when expanded in serum-free, xeno-free medium represent a viable source of MSCs for clinical use.

Non-orthodontic intervention and non-nutritive sucking behaviours: A literature review.

Anterior open bite (AOB) is one of the most complex malocclusions to manage. AOB is caused by either by skeletal, genetic or environmental factors. Numerous treatment options are currently utilised to manage AOB. These vary from non-invasive behavioural shaping to orthodontic and surgical interventions. This paper reviews the available orthodontic and non-orthodontic interventions used in the management of AOB. The literature review was carried out using the PubMed search engine from the first of January 2000 to the first of June 2017. Two major keywords (open bite and anterior open bite) were used in addition to 23 minor keywords in the review. AOB is one of the most complex malocclusions to treat with high relapse rates. Long term outcome in treatments of patients with AOB was substantially low. Relapse rates were not taken into consideration for some of the literature reviewed. Despite limitations of the literature, it is recommended that orofacial myofunctional therapy (OMT) and non-orthodontic intervention (NOI) be used in conjunction as an effective treatment option for Anterior Open Bite.

Comparative study of different centrifugation protocols for a density gradient separation media in isolation of osteoprogenitors from bone marrow aspirate.

INTRODUCTION: Human bone marrow contains osteoprogenitors capable of differentiating into osteoblasts. Density gradient centrifugation (DGC) is a commonly used method to isolate osteoprogenitors from bone marrow. Numerous studies used different dilution and centrifugation protocols, which might affect cell yields and quality. Moreover, the relative isolation efficiencies of the different separation protocols have not been investigated. This study compares the enrichment efficacy of the two different centrifugation protocols for a commonly used DGC media in isolation of osteoprogenitors. MATERIAL AND METHOD: Bone marrow was aspirated from human anterior iliac crests. Osteoprogenitors are isolated with Ficoll DGC media. A centrifugal force of 400 g and 1:1 dilution was compared with the centrifugal force of 1000 g after three dilution times with a buffer. RESULTS: The average numbers of isolated cells were significantly higher when using lower centrifugal force with 1:1 dilution, however, there was no detectable difference between Colony-forming unit-fibroblast (CFU-F) forming capacity, STRO-1 positivity, osteogenic differentiation or mineralization abilities between protocols. CONCLUSION: Both protocols could isolate competent and functional osteoprogenitors, while a lower centrifugal force (400 g) with 1:1 dilution produced recovery of more osteoprogenitors.