Dental Follicle Research Articles

CircFgfr2 promotes osteogenic differentiation of rat dental follicle cells by targeting the miR-133a-3p/DLX3 signaling pathway

Dental follicle cells (DFCs) promote bone regeneration in vivo and in vitro. Circular RNAs (circRNAs) play crucial roles in bone development and regeneration. Our previous study demonstrated the upregulation of circFgfr2 expression during the osteogenic differentiation of DFCs. However, the molecular mechanisms and functional roles of circFgfr2 in DFCs osteogenesis remain unclear. In this study, we aimed to investigate the subcellular localization of circFgfr2 in DFCs using fluorescence in situ hybridization. In vitro investigations demonstrated that circFgfr2 overexpression promoted osteogenic differentiation, as evidenced by real-time quantitative polymerase chain reaction. By integrating the outcomes of bioinformatics analyses, dual luciferase reporter experiments, and chromatin isolation by RNA purification, we identified circFgfr2 as a sponge for miR-133a-3p, a key regulator of osteogenic differentiation. Moreover, miR-133a-3p suppressed osteogenic differentiation by targeting DLX3 and RUNX2 in DFCs. We validated that circFgfr2 promoted the osteogenic differentiation of DFCs through the miR-133a-3p/DLX3 axis. To further investigate the therapeutic potential of circFgfr2 in bone regeneration, we conducted in vivo experiments and histological analyses. Overall, these results confirmed the crucial role of circFgfr2 in promoting osteogenesis. In summary, our findings demonstrated that the circFgfr2/miR-133a-3p/DLX3 pathway acts as a cascade, thereby identifying circFgfr2 as a promising molecular target for bone tissue engineering.

Proteomic profile of tissue-derived extracellular vesicles from benign odontogenic lesions

BackgroundBenign odontogenic lesions (BOLs) can cause severe jaw bone defects and compromise the quality of life of patients. Extracellular vesicles (EVs) are well-established and versatile players in mediating pathophysiological events. EVs in the interstitial space (tissue-derived EVs or Ti-EVs) possess higher specificity and sensitivity in disease-related biomarker discovery. However, the role of Ti-EV-loaded proteins in mediating the development of BOLs has remained untapped. Herein, we aim to explore the contribution of Ti-EV-loaded proteins to the development of BOLs. MethodsSamples were obtained from 3 with dental follicle, 3 with dentigerous cyst (DC), 7 with odontogenic keratocyst (OKC), and 3 patients with ameloblastoma (AM). Tissue-derived EVs were then extracted, purified, and validated using ultracentrifugation, transmission electron microscopy, and western blotting. Proteins from Ti-EVs were analyzed using LC-ESI tandem mass spectroscopy and differentially expressed proteins were screened, which was then validated by immunohistochemistry and immunofluorescence assays. ResultsThe protein profile of Ti-EVs in each group was mapped by LC-MS analysis. The top 10 abundant proteins in BOL-derived Ti-EVs were COL6A3, COL6A1, ALB, HIST1H4A, HBB, ACTB, HIST1H2BD, ANXA2, COL6A2 and FBN1. Additionally, unique proteins in the Ti-EVs from various lesions were identified. Moreover, focal adhesion kinase (FAK) and myeloid differentiation primary response 88 (MyD88) showed higher expressions in Ti-EVs derived from OKC and AM, which were confirmed by immunohistochemistry and immunofluorescence staining. ConclusionsTi-EVs containing FAK and MyD88 might be related to the development of OKC and AM, which can be potential therapeutic targets.

SNHG1 knockdown promotes osteogenic differentiation of hDFSCs through anti-oxidative stress mediated by autophagy.

The long noncoding RNA (lncRNA) small nucleolar RNA host gene 1 (SNHG1) plays a crucial role in tumorigenesis and is frequently employed as a prognostic biomarker. However, its involvement in the osteogenic differentiation of oral stem cells, particularly human dental follicle stem cells (hDFSCs), remains unclear. Our investigation revealed that the absence of SNHG1 enhances the osteogenic differentiation of hDFSCs. Furthermore, the downregulation of SNHG1 induces autophagy in hDFSCs, leading to a reduction in intracellular oxidative stress levels. Notably, this effect is orchestrated through the epigenetic regulation of EZH2. Our study unveils a novel function of SNHG1 in governing the osteogenic differentiation of hDFSCs, offering fresh insights for an in-depth exploration of the molecular mechanisms underlying dental follicle development. These findings not only provide a foundation for advancing the understanding of SNHG1 but also present innovative perspectives for promoting the repair and regeneration of periodontal supporting tissue, ultimately contributing to the restoration of periodontal health and tooth function.

CA1 Modulates the Osteogenic Differentiation of Dental Follicle Stem Cells by Activating the BMP Signaling Pathway In Vitro.

Carbonic anhydrase 1 (CA1) has been found to be involved in osteogenesis and osteoclast in various human diseases, but the molecular mechanisms are not completely understood. In this study, we aim to use siRNA and lentivirus to reduce or increase the expression of CA1 in Dental follicle stem cells (DFSCs), in order to further elucidate the role and mechanism of CA1 in osteogenesis, and provide better osteogenic growth factors and stem cell selection for the application of bone tissue engineering in alveolar bone fracture transplantation. The study used RNA interference and lentiviral vectors to manipulate the expression of the CA1 gene in DFSCs during in vitro osteogenic induction. The expression of osteogenic marker genes was evaluated and changes in CA1, alkaline phosphatase (ALP), Runt-related transcription factor 2 (RUNX2), and Bone morphogenetic proteins (BMP2) were measured using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting (WB). The osteogenic effect was assessed through Alizarin Red staining. The mRNA and protein expression levels of CA1, ALP, RUNX2, and BMP2 decreased distinctly in the si-CA1 group than other groups (p < 0.05). In the Lentivirus-CA1 (LV-CA1) group, the mRNA and protein expressions of CA1, ALP, RUNX2, and BMP2 were amplified to varying degrees than other groups (p < 0.05). Apart from CA1, BMP2 (43.01%) and ALP (36.69%) showed significant upregulation (p < 0.05). Alizarin red staining indicated that the LV-CA1 group produced more calcified nodules than other groups, with a higher optical density (p < 0.05), and the osteogenic effect was superior. CA1 can impact osteogenic differentiation via BMP related signaling pathways, positioning itself upstream in osteogenic signaling pathways, and closely linked to osteoblast calcification and ossification processes.

Bone Regeneration Facilitated by Autologous Bioscaffold Material: Liquid Phase of Concentrated Growth Factor with Dental Follicle Stem Cell Loading.

The application of bioengineering techniques for achieving bone regeneration in the oral environment is an increasingly prominent field. However, the clinical use of synthetic materials carries certain risks. The liquid phase of concentrated growth factor (LPCGF), as a biologically derived material, exhibits superior biocompatibility. In this study, LPCGF was employed as a tissue engineering scaffold, hosting dental follicle cells (DFCs) to facilitate bone regeneration. Both in vivo and in vitro experimental results demonstrate that this platform significantly enhances the expression of osteogenic markers in DFCs, such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2), and type I collagen (Col1a1). Simultaneously, it reduces the expression of inflammation-related genes, particularly interleukin-6 (IL-6) and interleukin-8 (IL-8), thereby alleviating the negative impact of the inflammatory microenvironment on DFCs. Further investigation into potential mechanisms reveals that this process is regulated over time by the WNT pathway. Our research results demonstrate that LPCGF, with its favorable physical characteristics, holds great potential as a scaffold. It can effectively carry DFCs, thereby providing an optimal initial environment for bone regeneration. Furthermore, LPCGF endeavors to closely mimic the mechanisms of bone healing post-trauma to facilitate bone formation. This offers new perspectives and insights into bone regeneration engineering.

Small extracellular vesicles derived from lipopolysaccharide-preconditioned dental follicle cells inhibit cell apoptosis and alveolar bone loss in periodontitis

ObjectiveThis study aimed to explore the effects of small extracellular vesicles derived from lipopolysaccharide-preconditioned dental follicle cells (L-D-sEV) on periodontal ligament cells from periodontitis affected teeth (p-PDLCs) in vitro and experimental periodontitis in mice. DesignIn vitro, the biological function of p-PDLCs and the underlying molecular mechanism were investigated by flow cytometry, Western blot, and quantitative real-time PCR (qRT-PCR) analysis. Eighteen-eight-week-old male C57BL/6 mice were randomly divided into three groups: control (Con), periodontitis (Peri), and L-D-sEV groups. Mice periodontitis model was induced by placing the 5–0 silk thread (around the maxillary second molar) and P.gingivalis (1 ×107 CFUs per mouse). In vivo, the alveolar bone loss, osteoclast activity, and macrophage polarization were measured by micro-computed tomography and histological analysis. ResultsIn vitro, the RANKL/OPG ratio and phosphorylation of JNK and P38 protein levels of p-PDLCs were significantly decreased after L-D-sEV administration. Besides, flow cytometry and qRT-PCR analysis showed that L-D-sEV reduced apoptosis of p-PDLCs, down-regulated apoptosis-related genes Caspase-3 and BCL-2-Associated X expression, and up-regulated B-cell lymphoma-2 gene levels. In vivo, L-D-sEV administration significantly reduced alveolar bone loss, inhibited osteoclast activity, and induced M2 polarization. The histological analysis showed that iNOS/CD206, RANKL/OPG, p-JNK/JNK, and p-P38/P38 ratios were significantly lower in the L-D-sEV group than in the Peri group. ConclusionsL-D-sEV administration alleviated alveolar bone loss by mediating RANKL/OPG-related osteoclast activity and M2 macrophage polarization, alleviating p-PDLCs apoptosis and proliferation via the JNK and P38 pathways.

FAM20A-Associated Amelogenesis Imperfecta: Gene Variants with Functional Verification and Histological Features.

To investigate FAM20A gene variants and histological features of amelogenesis imperfecta and to further explore the functional impact of these variants. Whole-exome sequencing (WES) and Sanger sequencing were used to identify pathogenic gene variants in three Chinese families with amelogenesis imperfecta. Bioinformatics analysis, in vitro histological examinations and experiments were conducted to study the functional impact of gene variants, and the histological features of enamel, keratinised oral mucosa and dental follicle. The authors identified two nonsense variants c. 406C > T (p.Arg136*) and c.826C > T (p.Arg176*) in a compound heterozygous state in family 1, two novel frameshift variants c.936dupC (p.Val313Argfs*67) and c.1483dupC (p.Leu495Profs*44) in a compound heterozygous state in family 2, and a novel homozygous frameshift variant c.530_531insGGTC (p.Ser178Valfs*21) in family 3. The enamel structure was abnormal, and psammomatoid calcifications were identified in both the gingival mucosa and dental follicle. The bioinformatics and subcellular localisation analyses indicated these variants to be pathogenic. The secondary and tertiary structure analysis speculated that these five variants would cause structural damage to FAM20A protein. The present results broaden the variant spectrum and clinical and histological findings of diseases associated with FAM20A, and provide useful information for future genetic counselling and functional investigation.

Advancements in Spinal Cord Injury Repair: Insights from Dental-Derived Stem Cells.

Spinal cord injury (SCI), a prevalent and disabling neurological condition, prompts a growing interest in stem cell therapy as a promising avenue for treatment. Dental-derived stem cells, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHED), stem cells from the apical papilla (SCAP), dental follicle stem cells (DFSCs), are of interest due to their accessibility, minimally invasive extraction, and robust differentiating capabilities. Research indicates their potential to differentiate into neural cells and promote SCI repair in animal models at both tissue and functional levels. This review explores the potential applications of dental-derived stem cells in SCI neural repair, covering stem cell transplantation, conditioned culture medium injection, bioengineered delivery systems, exosomes, extracellular vesicle treatments, and combined therapies. Assessing the clinical effectiveness of dental-derived stem cells in the treatment of SCI, further research is necessary. This includes investigating potential biological mechanisms and conducting Large-animal studies and clinical trials. It is also important to undertake more comprehensive comparisons, optimize the selection of dental-derived stem cell types, and implement a functionalized delivery system. These efforts will enhance the therapeutic potential of dental-derived stem cells for repairing SCI.

Assessment of glypican-3 immune expression in ameloblastoma, ameloblastic fibroma, ameloblastic carcinoma (pilot study)

BackgroundOdontogenic tumors a variety of benign and malignant lesions developed exclusively in the jaws. They are known to have variable clinical behaviors and different histological features. The development of odontogenic tumors is attributed to alterations in some genetic and biological molecules. The aim of this study is to assess Glypican-3 immune expression in different groups of odontogenic neoplasms as in Ameloblastoma, Ameloblastic Fibroma, and Ameloblastic Carcinoma, and compare it to dental follicle tissue as control group. Also correlate the marker expression with the known biological behavior of these tumors. This study included 40 cases were selected from oral and maxillofacial pathology department (ten cases in each group). Some sections are prepared to be stained with H&E stain and other sections with Glypican-3 immune stain. Histological examination and Histomorphometric analysis were done finally under light microscope. The area percents of Glypican-3 immune expression in all tumor sections were measured.ResultsLevel of expression of Glypican-3 revealed significant difference between the study groups (P-value < or = 0.05). The level of immune expression was highest in ameloblastic carcinoma group (M = 58.7) followed by ameloblastoma group (M = 33.9), then ameloblastic fibroma (M = 5.6) and lowest in the control group of dental follicle (M = 1.3).ConclusionsGlypican-3 immune expression demonstrated statistically significant difference among the study groups, indicating that it may have contributing role in tumor pathogenesis and its biological behavior.

The temporospatial relationship between mouse dental pulp stem cells and tooth innervation

Background/purposeDental pulp stem cells (DPSCs) exhibit versatile differentiation capabilities, including neural differentiation, prompting the hypothesis that they may be implicated in the neurodevelopment of teeth. This study aimed to explore the temporospatial dynamics between DPSCs and tooth innervation, employing immunofluorescence staining and fluorescent dye injections to investigate the distribution of DPSCs, neural stem cells (NSCs), nerve growth cones, and sensory nerves in developing mouse tooth germs at various stages. Materials and methodsImmunofluorescence staining targeting CD146, Nestin, and GAP-43, along with the injection of AM1-43 fluorescent dye, were utilized to observe the distribution of DPSCs, NSCs, nerve growth cones, and sensory nerves in mouse tooth germs at different developmental stages. ResultsPositive CD146 immunostaining was observed in microvascular endothelial cells and pericytes within and around the tooth germ. The percentage of CD146-positive cells remained consistent between 4-day-old and 8-day-old second molar tooth germs. Conversely, Nestin expression in odontoblasts and their processes decreased in 8-day-old tooth germs compared to 4-day-old ones. Positive immunostaining for GAP-43 and AM1-43 fluorescence revealed the entry of nerve growth cones and sensory nerves into the pulp in 8-day-old tooth germs, while these elements were confined to the dental follicle in 4-day-old germs. No co-localization of CD146-positive DPSCs with nerve growth cones and sensory nerves was observed. ConclusionDPSCs and NSCs were present in dental pulp tissue before nerves penetrated the pulp. The decline in NSCs after nerve entry suggests a potential role for DPSCs and NSCs in attracting neural growth and/or differentiation within the pulp.

DENTIGEROUS CYST IN CHILDREN: A RARE CASE REPORT

Dentigerous cysts are growths of the jaw's epithelial lining that develop from the dental follicle of unerupted teeth. These cysts are usually found during routine radiography exams, associated with immature teeth. Dentigerous cysts typically don't cause symptoms unless they get big enough to swell. Third, molars and maxillary canines are frequently associated with most dentigerous cysts. A diagnosis is made based on histopathological, radiological, and clinical findings. We describe an instance of a dentigerous cyst that was connected to two immature mandibular premolar teeth. This rare case report discusses the treatment of a dentigerous cyst in the lower premolar region of the left mandible. Under local anesthesia, the patient had surgical treatment that included the removal of two primary teeth and enucleation of the cyst. The evaluation revealed that one week after surgery, the recovery was complete.

Dental stem cells and their application in dental research: A review

Promising advancements in dental therapies aimed at replacing, repairing, and regenerating dental tissues have resulted from recent innovations in cell and molecular-based dentistry. Additionally, fresh approaches to the study of human tooth organogenesis have also been established. In recent days, five subpopulations of dental and oral stem cells have been identified, including dental pulp SCs (DPSCs), SCs from human exfoliated deciduous teeth (SHEDs), periodontal ligament SCs (PDLSCs), dental follicle progenitor SCs (DFPCs), and SCs from apical papilla (SCAPs). Teeth are one of the most accessible and least invasive sources of stem cells. Despite being unique, these populations exhibit traits common to MSCs, such as the capacity for self-renewal and the capacity to split into at least three separate lineages. Here in this article, the different sources of Dental stems cells and their characteristic features are discussed.

Fibroblast growth factor signalling regulates the development of tooth root.

Fibroblast growth factor (FGF) signalling plays a crucial role in the morphogenesis of multiple tissues including teeth. While the role of the signal has been studied in tooth crown development, little is known about root development. Of several FGF ligands involved in hard tissue formation, we suggest that FGF18 regulates the development of murine tooth roots. We implanted FGF18-soaked heparin beads into the lower first molar tooth buds at postnatal day 6 (P6), followed by transplantation under the kidney capsule. After 3 weeks, FGF18 significantly facilitated root elongation and periodontal tissue formation compared to the control. Insitu hybridisation showed that Fgf18 transcripts were initially localised in the dental pulp along Hertwig's epithelial root sheath at P6 and P10 and subsequently in the dental follicle cells at P14. Fgf receptors were expressed in various dental tissues during these stages. Invitro analysis using the dental pulp stem cells revealed that FGF18 inhibited cell proliferation and decreased expression levels of osteogenic markers, Runx2, Alpl and Sp7. Consistently, after 1 week of kidney capsule transplantation, FGF18 application did not induce the expression of Sp7 and Bsp, but upregulated Periostin in the apical region of dental mesenchyme in the grafted molar. These findings suggest that FGF18 facilitates molar root development by regulating the calcification of periodontal tissues.

A Comparative Study for Localization of Odontoclast in Crown and Root of Physiological Resorbed Primary Teeth

Root and crown resorption is a physiologic event for the primary teeth. It is still unclear whether odontoclasts, the cells which resorb the dental har d tissue, are different from the osteoclasts, the cells that resorb bone. Dental tissue resorption seems to be initiated and regulated by the stellate reticulum and the dental follicle of the underlying permanent tooth via the secretion of stimulatory molecules, i.e. cytokines and transcription factors. The primary teeth resorption process is regulated in a manner similar to bone remodeling, involving the same receptor ligand system known as RANK/RANKL (receptor activator of nuclear factor-kappa B/ RANK Ligand), which represent two cytokine-like proteins of the tumor necrosis factor superfamily, are localized on bone cells and dental cells .They are crucial for the regulation of osteoclastic/odontoclast cell differentiation and also for the upregulation of mature osteoclasts/odontoclasts mediated by cell-to-cell contact and a subsequent cascade of diverse intracellular signaling processes .The aim of the present study was to localize and compare the IHC rea ctions for RANKL along root surface and the crown of human phs iological resorbed primary teeth. Fifteen human upper deciduous (second molar) teeth ,undergoing root and crown resorption wer e used for immunohistochemical study to identify RANKL expre ssion. The results demonstrated a high mean of expression of R ANKL in root as compared with crown in human primary shedding teeth. The present study concludes that RANKL play a role in res orption process of the primary teeth.

Lyophilized platelet rich fibrin and gelatin incorporated bioadhesive bone cement composite for repair of mandibular continuity defects

Mandibular continuity defects stem from conditions such as malignancies, trauma, cysts, osteomyelitis and osteoradionecrosis, presenting significant challenges. If mandibular reconstruction fails, it can result in facial collapse, causing significant aesthetic and functional concerns for the patient. In the present study we developed a bio-adhesive Bone Cement (BC) enriched with lyophilised PRF and gelatin to enhance bone repair and induce regeneration. The developed BC consisted of a mixture of Tetracalcium Phosphate (TTCP) and O-Phospho-l-serine (OPLS) in addition to lyophilised Platelet Rich Fibrin (PRF) for sustained growth factor release and gelatin (GE) for improved cement resorption. It is primarily designed for in-situ application, conforming to the shape and size of the defect for effective bone repair and regeneration. The study evaluated four groups: (i) BC (control), (ii) BC-GE (control), (iii) BC-PRF, and (iv) BC-GE-PRF. All the four groups were characterised using FTIR, SEM and XRD. The mechanical studies of the prepared beads exhibited a significant increase in the compressive strength of the PRF loaded bone cement composites. In vitro degradation study of the beads over a 60-day period revealed a significantly higher percentage of bone cement resorption in the gelatin-incorporated groups, BC-GE (44 ± 0.5 %), and BC-GE-PRF (45 ± 2 %). The assessment of growth factor release (TGF-β and VEGF) using ELISA revealed a prolonged and sustained release of both growth factors over a 28-day period. In vitro studies were performed on human Dental Follicle Stem Cells (DFSCs) to assess cell attachment, proliferation, mineralisation and osteogenic differentiation. These studies clearly depicted that BC-PRF and BC-GE-PRF showed significantly greater proliferation of DFSCs. Furthermore, BC-PRF and BC-GE-PRF samples exhibited notably elevated expression of Runx2 and OPN (osteogenic markers), as well as a higher intensity of alizarin red stain (mineralisation). Therefore, it was concluded that PRF incorporated bioadhesive bone cement composites greatly enhance the cell attachment, proliferation, mineralisation and osteogenic differentiation of the DFSCs. Thus, the PRF and gelatin incorporated bone cement composites is expected to facilitate effective and faster bone regeneration and healing in a wide range of dental and maxillofacial defects.

Oral Health: The Potential of Mesenchymal Stem Cells in Treating Various Oral Diseases and Promoting Tissue Regeneration

The WHO Global Oral Health Status Report (2022) estimates that over 3.5 billion individuals worldwide have an oral disease. Most of the cases are dental caries, periodontal disease, tooth loss etc. Tooth loss will not only affect the balance of the oral environment but also cause negative effects on facial development and the patient's psychological condition. At present, The implement of oral stem cells to encourage tissue regeneration has become a hot trend. Among them, Periodontal Ligament Stem Cells (PDLSCs) and Dental Follicle Stem Cells (DFSCs) have been discovered it’s potential to promote tooth regeneration. Scientists proposed a variety of different treatment methods, including the use of advanced bioengineered technology to further target different oral diseases. So far, It is firmly established that oral stem cells have the potential to boost tissue regeneration.

Epidemiological and CBCT characterizations of odontomas: A retrospective study of 87,590 subjects.

This study aimed to assess the epidemiological and three-dimensional (3D) radiological characterizations of odontomas, as well as the spatial relationship between odontomas and gubernaculum tracts (GT). We retrieved the cone-beam computed tomography (CBCT) data of 87,590 patients. Dentition, location, type, diameter of the odontomas, width of the dental follicle (DF), the spatial relationship between the odontoma and GT, and the influence on adjacent teeth were evaluated. Significant differences were found in age, dentition, location, Max/Min diameter, width of DF, impaction, retention, and root bending of adjacent teeth among different spatial relationships between the odontoma and GT (all p < 0.05), as well as in age, type and size, absence, impaction, malposition, and retention of adjacent teeth among different locations of odontomas (all p < 0.05). Compared to the odontomas without impaction, those with impaction had larger diameter (p < 0.05 in all directions). This statistically significant association was consistent for odontomas with malposition, while no similar result was observed in the maximum diameter. Our findings provide the preliminary data for clinicians to comprehensively understand the incidence, radiographic characterizations and symptoms of odontoma in Chinese population.

Induced Pluripotent Stem Cells - A New Perspective toward Regenerative Dentistry and Prosthodontics: A Narrative Review Article

Aim: This study aims to review the unexplored area in regenerative prosthodontics using induced pluripotent stem (IPS) cells. Materials and Methods: A computer-based search was done from the year 1981 to 2020, but more specifically for IPS cells from 2006 and, the data were collected from various sources such as the National Center for Biotechnology Information (via PubMed), Medline semantic scholar, BioMed Central, Directory of Open Access Journals, Science Open, and Bielefeld Academic Search Engine using the keywords stem cells in dentistry, IPS cells, embryonic stem cells (ESCs), prosthodontic regeneration using induced pluripotent cells, stem cells from the periodontal ligament, dental pulp, deciduous tooth, and dental follicle. We have also systematically reviewed the method to generate IPS cells and their research in obtaining various organs that is of concern in dentistry and especially prosthodontics. Results: Based on the keywords and cross-referencing, 69 articles were valid and selected for review. The chosen articles are organized according to the subheadings in the order of their publication date. This literature is based on studies conducted on animals, and it does not include the transplantation of IPS cells in humans. In 2006, when Yamanaka and Takahashi discovered IPS cells, there was a spike rise in the study of these cells. The number of clinical trials for IPS cells was around 75%, whereas for ESCs was just 25%. Most of the clinical trials for IPS cells have been done in the USA (37%) whereas India accounts for only 1% of the study. Conclusion: This review article suggests the future of IPS cells in regenerative dentistry and prosthodontics. It gives information on the types of stem cells, why IPS cells have been chosen for the review, the source of IPS cells, the method of induction of IPS cells, and their use in prosthodontics and implantology.

The effect of the dental follicle volume of palatally impacted canines on the relative position of the adjacent teeth.

To assess if the dental follicle volume of palatally impacted canines (PICs) affects the relative root position of the adjacent lateral incisors (LIs) and first premolars (FPs). A retrospective cross-sectional study of 49 patients with unilaterally PICs with dental follicles who had CBCT imaging previously taken. Four orthodontic centers in different countries provided the sample. A mean difference of 5° between the angular measurements (mesiodistal tip, buccolingual inclination, or mesiodistal rotation) of the LI and FP adjacent to the PIC and the controls was considered clinically relevant. A value of 0.05 was set for significance level and a power of 80%. The minimum sample size was determined to be 26 patients. These patients were further assigned to an LI sample (n = 49) and an FP sample (n = 23), dependent on the direct contact of the dental follicle to that adjacent tooth. A manual segmentation technique was used to obtain the volumetric measurements of the dental follicle. Angular measurements of adjacent teeth were then compared to the contralateral nonimpacted side, which acted as the control. A multivariant regression analysis was performed using IBM SPSS software, and statistical significance was set at α = 0.05. Adequate intra-rater reliability was accomplished. The multivariant regression analysis implied that there is no difference in the mean change in the tip, torque, and rotation of the LI and FP between the impacted and control sides when dental follicle volumes are considered (P = .509 for the LI sample and P = .804 for the FP sample). CBCT imaging of dental follicle border delimitations, partial volume effect, and scattering are limitations. This is a convenience sample where the FP subsample is small. The dental follicle volume of the PICs does not seem to influence the relative position of the adjacent LI and FP mesiodistal tip, buccolingual inclination, and mesiodistal rotation. Early intervention could have been suggested to avoid certain malocclusion traits if significant displacements were demonstrated.

Additional Insights Into the Role of Osteocalcin in Osteoblast Differentiation and in the Early Steps of Developing Alveolar Process of Rat Molars.

This study investigated whether osteocalcin (OCN) is present in osteoblast precursors and its relationship with initial phases of alveolar process formation. Samples of maxillae of 16-, 18-, and 20-day-old rat embryos (E16, E18, and E20, respectively), and 05-, 10-, and 15-day-old postnatal rats (P05, P10, and P15, respectively) were fixed and embedded in paraffin or araldite. Immunohistochemistry for osterix (Osx), alkaline phosphatase (ALP), and OCN detection was performed and the number of immunolabelled cells was computed. Non-decalcified sections were subjected to the von Kossa method combined with immunohistochemistry for Osx or OCN detection. For OCN immunolocalization, samples were fixed in 0.5% glutaraldehyde/2% formaldehyde and embedded in LR White resin. The highest number of ALP- and OCN-immunolabelled cells was observed in dental follicle of E16 specimens, mainly in basal portions of dental alveolus. In corresponding regions, osteoblasts in differentiation adjacent to von Kossa-positive bone matrix exhibited Osx and OCN immunoreactivity. Ultrastructural analysis revealed OCN immunoreactive particles inside osteoblast in differentiation, and in bone matrix associated with collagen fibrils and within matrix vesicles, at early stages of alveolar process formation. Our results indicate that OCN plays a role in osteoblast differentiation and may regulate calcium/phosphate precipitation during early mineralization of the alveolar process.