UNASSIGNED: Odontogenic cysts and tumors develop from the dental follicle of asymptomatic impacted teeth. Odontogenic tissues express the epidermal growth factor receptor family (EGFR), which mediates cell proliferation, survival, and neoplastic differentiation. The present study aimed to compare the immunohistochemical expression of EGFR and human epidermal growth factor receptor 2 (HER2) in the dental follicle of impacted wisdom teeth with normal and abnormal radiographic size.
UNASSIGNED: In this analytical study, immunohistochemical staining of EGFR and HER2 was performed on 30 normal and 30 abnormal follicles of impacted third molars. Follicles with a width of <2.5 mm were considered normal, whereas those with a width of ≥2.5 mm were regarded as abnormal. The immunoreactive score (IRS) was used to report the expression levels of EGFR and HER2. The obtained data were analyzed using SPSS software. Age and sex were compared in normal and abnormal groups with independent t test and Chi square test, respectively. P<0.05 was considered statistically significant.
UNASSIGNED: The EGFR and HER2 overall expression was high in all normal and abnormal follicles. The comparison of the percentage of stained cells and intensity of EGFR and HER2 staining in normal and abnormal follicles were not significantly different (P=0.73, P=0.63, P=0.95, respectively).
UNASSIGNED: Due to the high expression of EGFR and HER2 in normal and abnormal follicles, as well as the lack of significant differences in these two groups, the radiographic size of dental follicles might not indicate the potential capabilities of their cells, and more research in this field is recommended.

BACKGROUND: Periodontal tissue loss is the main reason for tooth mobility and loss caused by periodontal disease. Dental follicle stem cells (DFSCs) have significant therapeutic potential in periodontal regeneration, which maybe mainly depends on their potent immunomodulatory capacity. Consequently, this study aims to elucidate the impact of implanted xenogenous DFSCs on innate immune responses during early and late stages in the periodontal defect repair period.
METHODS: To trace and investigate the immunomodulation mechanisms of DFSCs in vivo, DFSCs were engineered (E-DFSCs) using lentiviral vectors expressing CD63-enhanced green fluorescent protein (CD63-EGFP) and β-Actin-mCherry protein (ACTB-mCherry) to exhibit green and red fluorescence. The biological characteristics and functions of E-DFSCs were verified by proliferation, differentiation, and co-culture experiments in vitro. In vivo, the periodontal regeneration capacity of E-DFSCs was detected by implantation of murine periodontal defect model, and the response of innate immune cells was detected at the 1st, 3rd, and 5th days (early stage) and 4th week (late stage) after implantation.
RESULTS: In vitro assessments showed that E-DFSCs retain similar properties to their non-engineered counterparts but exhibit enhanced macrophage immunomodulation capability. In mice models, four-week micro-CT and histological evaluations indicated that E-DFSCs have equivalent efficiency to DFSCs in periodontal defect regeneration. At the early stage of repair in mice periodontal defect, fluorescence tracking showed that implanted E-DFSCs might primarily activate endogenous cells through direct contact and indirect actions, and most of these cells are myeloperoxidase-positive neutrophils. Additionally, compared with the control group, the neutrophilic infiltration and conversion of N2-type were significantly increased in the E-DFSC group. At the late stage of defect regeneration, more M2-type macrophages, fewer TRAP + osteoclasts, and an upregulated OPG/RANKL ratio were detected in the E-DFSC group compared to the control group, which indicated that immune balance tilts towards healing and bone formation.
CONCLUSIONS: The xenogenous implanted DFSCs can induce the N2 phenotype of neutrophils in the early stage, which can activate the innate immune mechanism of the host to promote periodontal tissue regeneration.

The dental follicle (DF) plays an indispensable role in tooth eruption by regulating bone remodeling through their influence on osteoblast and osteoclast activity. The process of tooth eruption involves a series of intricate regulatory mechanisms and signaling pathways. Disruption of the parathyroid hormone‑related protein (PTHrP) in the PTHrP‑PTHrP receptor signaling pathway inhibits osteoclast differentiation by DF cells (DFCs), thus resulting in obstructed tooth eruption. Furthermore, parathyroid hormone receptor‑1 mutations are linked to primary tooth eruption failure. Additionally, the Wnt/β‑catenin, TGF‑β, bone morphogenetic protein and Hedgehog signaling pathways have crucial roles in DFC involvement in tooth eruption. DFC signal loss or alteration inhibits osteoclast differentiation, affects osteoblast and cementoblast differentiation, and suppresses DFC proliferation, thus resulting in failed tooth eruptions. Abnormal tooth eruption is also associated with a range of systemic syndromes and genetic diseases, predominantly resulting from pathogenic gene mutations. Among these conditions, the following disorders arise due to genetic mutations that disrupt DFCs and impede proper tooth eruption: Cleidocranial dysplasia associated with Runt‑related gene 2 gene mutations; osteosclerosis caused by CLCN7 gene mutations; mucopolysaccharidosis type VI resulting from arylsulfatase B gene mutations; enamel renal syndrome due to FAM20A gene mutations; and dentin dysplasia caused by mutations in the VPS4B gene. In addition, regional odontodysplasia and multiple calcific hyperplastic DFs are involved in tooth eruption failure; however, they are not related to gene mutations. The specific mechanism for this effect requires further investigation. To the best of our knowledge, previous reviews have not comprehensively summarized the syndromes associated with DF abnormalities manifesting as abnormal tooth eruption. Therefore, the present review aims to consolidate the current knowledge on DFC signaling pathways implicated in abnormal tooth eruption, and their association with disorders of tooth eruption in genetic diseases and syndromes, thereby providing a valuable reference for future related research.

BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.

N6-methyladenosine (m6A) is the most abundant RNA modification, regulating gene expression in physiological processes. However, its effect on the osteogenic differentiation of dental follicle stem cells (DFSCs) remains unknown. Here, m6A demethylases, the fat mass and obesity-associated protein (FTO), and alkB homolog 5 (ALKBH5) were overexpressed in DFSCs, followed by osteogenesis assay and transcriptome sequencing to explore potential mechanisms. The overexpression of FTO or ALKBH5 inhibited the osteogenesis of DFSCs, evidenced by the fact that RUNX2 independently decreased calcium deposition and by the downregulation of the osteogenic genes OCN and OPN. MiRNA profiling revealed that miR-7974 was the top differentially regulated gene, and the overexpression of m6A demethylases significantly accelerated miR-7974 degradation in DFSCs. The miR-7974 inhibitor decreased the osteogenesis of DFSCs, and its mimic attenuated the inhibitory effects of FTO overexpression. Bioinformatic prediction and RNA sequencing analysis suggested that FK506-binding protein 15 (FKBP15) was the most likely target downstream of miR-7974. The overexpression of FKBP15 significantly inhibited the osteogenesis of DFSCs via the restriction of actin cytoskeleton organization. This study provided a data resource of differentially expressed miRNA and mRNA after the overexpression of m6A demethylases in DFSCs. We unmasked the RUNX2-independent effects of m6A demethylase, miR-7974, and FKBP15 on the osteogenesis of DFSCs. Moreover, the FTO/miR-7974/FKBP15 axis and its effects on actin cytoskeleton organization were identified in DFSCs.

OBJECTIVE: To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles.
METHODS: Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy.
RESULTS: A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05).
CONCLUSIONS: In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.
目的: 总结既往上前牙区埋伏牙开放式牵引方法的基础上，报告一种基于牙囊的软组织处理技术，并监测治疗后埋伏牙牙根长度变化和牙槽骨丢失量，探讨牙囊在埋伏上颌中切牙唇侧微创开放式牵引中的重要作用。方法: 选择单侧唇侧埋伏上颌中切牙并采用开放式牵引技术治疗的患者，将埋伏中切牙纳入试验组，将对侧未受影响的中切牙纳入对照组。在外科手术暴露埋伏上颌中切牙时，利用埋伏牙周围的牙囊组织进行术区软组织管理，最大程度地保存埋伏牙周围软硬组织量。在埋伏上颌中切牙牵引至牙合平面后，记录其牙长、根长、骨丢失量、骨厚度等测量值。结果: 成功牵引了17例单侧唇侧埋伏上颌中切牙。牵引后试验组与对照组之间，牙长、根长、唇侧骨丢失量的差异有统计学意义（P<0.05），唇-腭釉牙骨质界处宽度、腭侧骨丢失量、唇侧骨厚度、腭侧骨厚度、根尖牙槽骨厚度的差异无统计学意义（P>0.05）。结论: 在外科手术暴露唇侧埋伏上颌中切牙时，本方法利用埋伏牙周围的牙囊组织进行术区软组织管理，最大程度地保存埋伏牙周围软硬组织量，尽可能在牵引萌出后获得更好的美学效果和健康的牙周组织。.

Dental mesenchymal stem cells (MSCs) are potential for use in tissue regeneration in inflammatory diseases due to their rapid proliferating, multilineage differentiation, and strong anti-inflammatory features. In the present study, immunoregulatory and glandular tissue regeneration effects of the dental follicle (DF)MSCs in Sjögren\'s Syndrome (SS) were investigated.
Dental follicle (DF) tissues were obtained from healthy individuals during tooth extraction, tissues were digested enzymatically and DFMSCs were cultured until the third passage. DFMSCs were labeled with Quantum dot 655 for cell tracking analysis. The induction of the SS mouse model was performed by the injection of Ro60-273-289 peptide intraperitoneally. DFMSCs were injected intraperitoneally, or into submandibular, or lacrimal glands. Splenocytes were analyzed for intracellular cytokine (IFN-γ, IL-17, IL-10) secretion in T helper cells, lymphocyte proliferation, and B lymphocyte subsets. Histologic analysis was done for submandibular and lacrimal glands with hematoxylin-eosin staining for morphologic examination.
The systemic injection of DFMSCs significantly reduced intracellular IFN-γ and IL-17 secreting CD4+ T cells in splenocytes (p<0.05), and decreased inflammatory cell deposits and fibrosis in the glandular tissues. DFMSCs differentiated to glandular epithelial cells in submandibular and lacrimal injections with a significant reduction in lymphocytic foci. The results showed that few amounts of DFMSCs were deposited in glandular tissues when applied intraperitoneally, while high amounts of DFMSCs were located in glandular tissues and differentiated to glandular epithelial cells when applied locally in SS murine model.
DFMSCs have the potential for the regulation of Th1, Th17, and Treg balance in SS, and ameliorate glandular dysfunction. DFMSCs can be a beneficial therapeutic application for SS.

OBJECTIVE: Lipopolysaccharide (LPS) pretreatment can enhance the therapeutic effect of dental follicle stem cells-derived small extracellular vesicles (DFC-sEV) for periodontitis, and this study aimed to investigate the underlying mechanisms and clinical application Of LPS-preconditioned DFC-sEV in periodontitis.
METHODS: The protein spectrum of DFC-sEV before and after LPS pretreatment was determined by liquid chromatography-tandem mass spectrometry and bioinformatic analysis. Their effects on inflammatory periodontal ligament stem cells (PDLSCs) and macrophages were investigated for cell proliferation, migration, type 2 macrophage (M2) polarization, and intracellular reactive oxygen species (ROS) levels separately. In addition, the regulation of ROS/Jun amino-terminal kinases (JNK) and ROS/extracellular signal-related kinases (ERK) signaling by LPS-preconditioned DFC-sEV was also studied to reveal the antioxidant mechanism. In vivo, two kinds of DFC-sEV loaded with 0.2% hyaluronic acid (HA) gel were applied for canine periodontitis to evaluate the therapeutic potential.
RESULTS: The proteomic analysis showed that thirty-eight proteins were differentially expressed in LPS-preconditioned DFC-sEV, and interestingly, the highly expressed proteins were mainly involved in antioxidant and enzyme-regulating activities. In addition to promoting PDLSCs and macrophage proliferation, LPS-preconditioned DFC-sEV inhibited intracellular ROS as an antioxidant. It reduced the RANKL/OPG ratio of PDLSCs by inhibiting ROS/JNK signaling under inflammatory conditions and promoted macrophages to polarize toward the M2 phenotype via ROS/ERK signaling. Furthermore, LPS-preconditioned DFC-sEV loaded with the HA injectable system could sustainably release sEV and enhance the therapeutic efficacy for periodontitis in canines.
CONCLUSIONS: LPS-preconditioned DFC-sEV could be effectively used as an auxiliary method for periodontitis treatment via antioxidant effects in a subgingival environment, and loading it with HA is feasible and effective for clinical applications.

Aging is not a matter of choice; it is our fate. The \"time-dependent functional decline that affects most living organisms\" is coupled with several alterations in cellular processes, such as cell senescence, epigenetic alterations, genomic instability, stem cell exhaustion, among others. Age-related morphological changes in dental follicles have been investigated for decades, mainly motivated by the fact that cysts and tumors may arise in association with unerupted and/or impacted teeth. The more we understand the physiology of dental follicles, the more we are able to contextualize biological events that can be associated with the occurrence of odontogenic lesions, whose incidence increases with age. Thus, our objective was to assess age-related changes in metabolic pathways of dental follicles associated with unerupted/impacted mandibular third molars from young and adult individuals. For this purpose, a convenience sample of formalin-fixed paraffin-embedded (FFPE) dental follicles from young (<16 y.o., n = 13) and adult (>26 y.o., n = 7) individuals was selected. Samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based untargeted metabolomics. Multivariate and univariate analyses were conducted, and the prediction of altered pathways was performed by mummichog and Gene Set Enrichment Analysis (GSEA) approaches. Dental follicles from young and older individuals showed differences in pathways related to C21-steroid hormone biosynthesis, bile acid biosynthesis, galactose metabolism, androgen and estrogen biosynthesis, starch and sucrose metabolism, and lipoate metabolism. We conclude that metabolic pathways differences related to aging were observed between dental follicles from young and adult individuals. Our findings support that similar to other human tissues, dental follicles associated with unerupted tooth show alterations at a metabolic level with aging, which can pave the way for further studies on oral pathology, oral biology, and physiology.

OBJECTIVE: Dental follicle (DF) is made up of mesenchymal cells and fibers surrounding the enamel organ of a developing tooth. It has been shown that cystic and neoplastic lesions can develop from the pericoronal follicles of impacted third molars (ITMs). But the molecular transformation of DF tissues has not yet been uncovered and remains elusive. Accordingly, in the present study, we aimed to investigate the differential expression of lncRNA genes in DF tissues associated with asymptomatic impacted mandibular third molars (IMTMs) that do not show pathological pericoronal radiolucency in radiographic examination.
METHODS: A total of 30 patients with unilateral mesioangular IMTMs were enrolled for the study. The expressions of lncRNA genes were determined in the DF and healthy gingival tissues obtained from study patients. For the determination of lncRNA expression levels, RNA was isolated from the obtained tissues, converted to cDNA samples, and analyzed by quantitative real-time PCR method.
RESULTS: As a result, we found that the gene expression of MEG3 was increased about 10-fold in DF tissues compared to healthy gingival tissues (p < 0.0001). In addition, NORAD expression was found to be upregulated 4.2-fold (p = 0.0002) in DF tissues. Also, expression level of MALAT1 was found to be decreased 1.24-fold (p = 0.584) and TP73-AS1 increased 2.6-fold (p = 0.093) in DF tissues compared to healthy gingival tissues.
CONCLUSIONS: Consequently, present findings suggest that differentially expressed lncRNAs in DFs might be associated with the various levels of cellular events including osteogenic differentiation, DNA damage, and the transformation into odontogenic pathology.
CONCLUSIONS: Expression levels of MEG3 and NORAD lncRNA molecules may guide clinicians in the evaluation of asymptomatic ITM dental follicles that cannot be determined radiologically and during extraction of these teeth for prophylactic purposes.