-
Journal of Oral Biosciences Sep 2022Tooth identification is important not only for anatomists and anthropologists but also for dental practitioners and dental students studying dental anatomy courses. This... (Review)
Review
BACKGROUND
Tooth identification is important not only for anatomists and anthropologists but also for dental practitioners and dental students studying dental anatomy courses. This review paper provides an overview of the significance of tooth identification focusing on the morphological and developmental background.
HIGHLIGHT
The process of tooth identification comprises five steps of distinction: (1) between deciduous and permanent teeth; (2) between tooth classes; (3) between maxillary and mandibular teeth; (4) within the same tooth class; and (5) between the left and right sides of a tooth. According to Mühlreiter's features, the mesial half is more developed than the distal half, and the curvature feature is associated with the configuration of the dental arch. Each step of tooth identification refers to effective traits and characteristics. The possibility that systemic conditions affect dental morphology should be considered. Tooth identification is occasionally difficult owing to individual variations (size and shape, supernumerary tubercles, root fusion) and sex-based differences. A tooth type error within the same class is the most frequent error in tooth identification, followed by a left or right side error.
CONCLUSION
To understand tooth identification, it is necessary to have comprehensive knowledge of dental morphology. A broad education with regard to tooth evolution and comparative odontology, as well as a thorough understanding of the morphology and function of teeth, which play a crucial role in sustaining life as organs of mastication, is essential.
Topics: Dentition; Humans; Odontogenesis; Tooth
PubMed: 35598838
DOI: 10.1016/j.job.2022.05.004 -
BACH1 regulates the proliferation and odontoblastic differentiation of human dental pulp stem cells.BMC Oral Health Nov 2022The preservation of biological and physiological vitality as well as the formation of dentin are among the main tasks of human dental pulp for a life time. Odontoblastic...
BACKGROUND
The preservation of biological and physiological vitality as well as the formation of dentin are among the main tasks of human dental pulp for a life time. Odontoblastic differentiation of human dental pulp stem cells (hDPSCs) exhibits the capacity of dental pulp regeneration and dentin complex rebuilding. Exploration of the mechanisms regulating differentiation and proliferation of hDPSCs may help to investigate potential clinical applications. BTB and CNC homology 1 (BACH1) is a transcription repressor engaged in the regulation of multiple cellular functions. This study aimed to investigate the effects of BACH1 on the proliferation and odontoblastic differentiation of hDPSCs in vitro.
METHODS
hDPSCs and pulpal tissues were obtained from extracted human premolars or third molars. The distribution of BACH1 was detected by immunohistochemistry. The mRNA and protein expression of BACH1 were examined by qRT-PCR and Western blot analysis. BACH1 expression was regulated by stable lentivirus-mediated transfection. Cell proliferation and cell cycle were assessed by cell counting kit-8 assay, 5-Ethynyl-2'-deoxyuridine assay and flow cytometry. The expression of mineralization markers, alkaline phosphatase (ALP) activity and alizarin red S staining were conducted to assess the odontoblastic differentiation ability.
RESULTS
BACH1 expression was stronger in the odontoblast layer than in the cell rich zone. The total and nuclear protein level of BACH1 during odontoblastic differentiation was downregulated initially and then upregulated gradually. Knockdown of BACH1 greatly inhibited cell proliferation, arrested cell cycle, upregulated the heme oxygenase-1 (HO-1) expression and attenuated ALP activity, decreased calcium deposits and downregulated the expression of mineralization markers. Treatment of Tin-protoporphyrin IX, an HO-1 inhibitor, failed to rescue the impaired odonto/osteogenic differentiation capacity. Overexpression of BACH1 increased cell proliferation, ALP activity and the expression of mineralization markers.
CONCLUSIONS
Our findings suggest that BACH1 is an important regulator of the proliferation and odontoblastic differentiation of hDPSCs in vitro. Manipulation of BACH1 expression may provide an opportunity to promote the regenerative capacity of hDPSCs.
Topics: Humans; Basic-Leucine Zipper Transcription Factors; Cell Proliferation; Dental Pulp; Osteogenesis; Regeneration; Stem Cells
PubMed: 36424585
DOI: 10.1186/s12903-022-02588-2 -
Journal, Genetic Engineering &... Oct 2023Tuftelin 1 (TUFT1) gene is important in the development and mineralization of dental enamel. The study aimed to identify potential functionally deleterious...
BACKGROUND
Tuftelin 1 (TUFT1) gene is important in the development and mineralization of dental enamel. The study aimed to identify potential functionally deleterious non-synonymous SNPs (nsSNPs) in the TUFT1 gene by using different in silico tools. The deleterious missense SNPs were identified from SIFT, PolyPhen-2, PROVEAN, SNPs & GO, PANTHER, and SNAP2. The stabilization, conservation, and three-dimensional modeling of mutant proteins were analyzed by I-Mutant 3.0, Consurf, and Project HOPE, respectively. The protein-protein interaction using STRING, GeneMANIA for gene-gene interaction, and DynaMut for evaluating the impact of the mutation on protein stability, conformation, and flexibility.
RESULTS
Eight deleterious nsSNPs (E242A, R303W, K182N, K123N, R117W, H289Q, R203W, and Q107R) out of 304 were found to have high-risk damaging effects using six in silico tools. Among them, K182N and K123N alone had increased stability, whereas E242A, R303W, R117W, H289Q, Q107R, and R203W exhibited a decrease in protein stability, based on DDG values. Meanwhile, all the eight deleterious nsSNPs altered the size, charge, hydrophobicity, and spatial organization of the amino acids and predominantly had alpha helix domains. These deleterious variants were located in highly conserved regions except R203W. Protein-protein interaction predicted that TUFT1 interacted with ten proteins that are involved in enamel mineralization and odontogenesis. Gene-gene interaction network showed that TUFT1 is involved in physical interactions, gene co-localization, and pathway interactions. DynaMut ΔΔG values predicted that five nsSNPs were destabilizing the protein, ΔΔG ENCoM values showed a destabilizing effect for all mutants, and seven nsSNPs increased the molecular flexibility of TUFT1.
CONCLUSION
Our study predicted eight functional SNPs that had detrimental effects on the structure and function of the TUFT1 gene. This will aid in the development of candidate deleterious markers as a potential target for disease diagnosis and therapeutic interventions.
PubMed: 37801178
DOI: 10.1186/s43141-023-00551-4 -
International Dental Journal Feb 2024The aim of this research was to investigate the functions of Piezo channels in dentin defect, including mechanical signalling and odontoblast responses.
OBJECTIVES
The aim of this research was to investigate the functions of Piezo channels in dentin defect, including mechanical signalling and odontoblast responses.
METHODS
Rat dentin-defect models were constructed, and spatiotemporal expression of Piezo proteins was detected in the pulpo-dentinal complex. Real-time polymerase chain reaction (rtPCR) was used to investigate the functional expression pattern of Piezo channels in odontoblasts. Moreover, RNA interference technology was employed to uncover the underlying mechanisms of the Piezo-driven inflammatory response and repair under fluid shear stress (FSS) conditions in vitro.
RESULTS
Piezo1 and Piezo2 were found to be widely expressed in the odontoblast layer and dental pulp in the rat dentin-defect model during the end stage of reparative dentin formation. The expression levels of the Piezo1 and Piezo2 genes in MDPC-23 cells were high in the initial stage under FSS loading and then decreased over time. Moreover, the expression trends of inflammatory, odontogenic, and mineralisation genes were generally contrary to those of Piezo1 and Piezo2 over time. After silencing of Piezo1/Piezo2, FSS stimulation resulted in significantly higher expression of inflammatory, odontogenesis, and mineralisation genes in MDPC-23 cells. Finally, the expression of genes involved in the integrin β1/ERK1 and Wnt5b/β-catenin signalling pathways was changed in response to RNA silencing of Piezo1 and Piezo2.
CONCLUSIONS
Piezo1 and Piezo2 may be involved in regulating the expression of inflammatory and odontogenic genes in odontoblasts stimulated by FSS.
Topics: Rats; Humans; Animals; Odontoblasts
PubMed: 37833209
DOI: 10.1016/j.identj.2023.07.002 -
BMC Pediatrics Sep 2021Vitamin D is traditionally associated with the metabolism of calcium and phosphorus, a process essential for the mineralization of hard tissue such as bone or tooth....
BACKGROUND
Vitamin D is traditionally associated with the metabolism of calcium and phosphorus, a process essential for the mineralization of hard tissue such as bone or tooth. Deficiency of this vitamin is a problem worldwide, however. Given the possibly significant role of Vitamin D in odontogenesis in children, the objective of our study was to determine the influence of vitamin D levels in the blood on dental anomalies in children between 6 and 10 years of age, by means of 25-hydroxy vitamin D tests performed during pregnancy and the first years of life.
METHODS
The data analyzed were sourced from data belonging to the INMA-Asturias birth cohort, a prospective cohort study initiated in 2004 as part of the INMA Project. The 25-hydroxy vitamin D (25(OH)D) test was performed with samples from 188 children in the INMA-Asturias birth cohort with a dental examination performed between 6 and 10 years of age. The samples were taken at three stages: in the mother at 12 weeks of gestation, and subsequently in the child at 4 and 8 years of age. Diet, nutritional and oro-dental hygiene habits were also analyzed by means of questionnaires.
RESULTS
The results indicate a significant association between caries and correct or incorrect brushing technique. With incorrect brushing technique, the prevalence of caries was 48.89%, but this dropped to 22.38% with correct brushing technique. An association was also found between tooth decay and frequency of sugar intake. The prevalence of caries was 24.54% with occasional sugar intake, but this rose to 56% with regular sugar intake. On the other hand, levels < 20 ng/ml in both mother and child at 8 years of age would also be risk factors (OR = 2.51(1.01-6.36) and OR = 3.45(1.14-11.01)) for the presence of caries in children. The risk of caries practically tripled where 25(OH) D values were < 20 ng/ml.
CONCLUSIONS
Although incorrect brushing technique and regular sugar consumption was found to be the main cause of caries in the children, the low concentrations of vitamin D in the blood of the pregnant mothers may have magnified this correlation, indicating that the monitoring of vitamin D levels during pregnancy should be included in antenatal programmes. It is particularly striking that 50% of the children were deficient in vitamin D at the age of 4, and that dental floss was practically absent from regular cleaning routines.
Topics: Adult; Child; Dental Caries; Dental Caries Susceptibility; Female; Humans; Pregnancy; Prospective Studies; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 34479530
DOI: 10.1186/s12887-021-02857-z -
Proceedings of the National Academy of... Aug 2020As the hardest tissue formed by vertebrates, enamel represents nature's engineering masterpiece with complex organizations of fibrous apatite crystals at the nanometer...
As the hardest tissue formed by vertebrates, enamel represents nature's engineering masterpiece with complex organizations of fibrous apatite crystals at the nanometer scale. Supramolecular assemblies of enamel matrix proteins (EMPs) play a key role as the structural scaffolds for regulating mineral morphology during enamel development. However, to achieve maximum tissue hardness, most organic content in enamel is digested and removed at the maturation stage, and thus knowledge of a structural protein template that could guide enamel mineralization is limited at this date. Herein, by examining a gene-modified mouse that lacked enzymatic degradation of EMPs, we demonstrate the presence of protein nanoribbons as the structural scaffolds in developing enamel matrix. Using in vitro mineralization assays we showed that both recombinant and enamel-tissue-based amelogenin nanoribbons are capable of guiding fibrous apatite nanocrystal formation. In accordance with our understanding of the natural process of enamel formation, templated crystal growth was achieved by interaction of amelogenin scaffolds with acidic macromolecules that facilitate the formation of an amorphous calcium phosphate precursor which gradually transforms into oriented apatite fibers along the protein nanoribbons. Furthermore, this study elucidated that matrix metalloproteinase-20 is a critical regulator of the enamel mineralization as only a recombinant analog of a MMP20-cleavage product of amelogenin was capable of guiding apatite mineralization. This study highlights that supramolecular assembly of the scaffold protein, its enzymatic processing, and its ability to interact with acidic carrier proteins are critical steps for proper enamel development.
Topics: Amelogenesis; Amelogenin; Animals; Apatites; Dental Enamel; Dental Enamel Proteins; Mice; Nanofibers
PubMed: 32737162
DOI: 10.1073/pnas.2007838117 -
Journal of Bone and Mineral Research :... Feb 2022Considerable amount of research has been focused on dentin mineralization, odontoblast differentiation, and their application in dental tissue engineering. However, very...
Considerable amount of research has been focused on dentin mineralization, odontoblast differentiation, and their application in dental tissue engineering. However, very little is known about the differential role of functionally and spatially distinct types of dental epithelium during odontoblast development. Here we show morphological and functional differences in dentin located in the crown and roots of mouse molar and analogous parts of continuously growing incisors. Using a reporter (DSPP-cerulean/DMP1-cherry) mouse strain and mice with ectopic enamel (Spry2 ;Spry4 ), we show that the different microstructure of dentin is initiated in the very beginning of dentin matrix production and is maintained throughout the whole duration of dentin growth. This phenomenon is regulated by the different inductive role of the adjacent epithelium. Thus, based on the type of interacting epithelium, we introduce more generalized terms for two distinct types of dentins: cementum versus enamel-facing dentin. In the odontoblasts, which produce enamel-facing dentin, we identified uniquely expressed genes (Dkk1, Wisp1, and Sall1) that were either absent or downregulated in odontoblasts, which form cementum-facing dentin. This suggests the potential role of Wnt signalling on the dentin structure patterning. Finally, we show the distribution of calcium and magnesium composition in the two developmentally different types of dentins by utilizing spatial element composition analysis (LIBS). Therefore, variations in dentin inner structure and element composition are the outcome of different developmental history initiated from the very beginning of tooth development. Taken together, our results elucidate the different effects of dental epithelium, during crown and root formation on adjacent odontoblasts and the possible role of Wnt signalling which together results in formation of dentin of different quality. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
Topics: Animals; Cell Differentiation; Dentin; Epithelium; Extracellular Matrix Proteins; Incisor; Mice; Odontoblasts; Odontogenesis
PubMed: 34783080
DOI: 10.1002/jbmr.4471 -
Journal of Dental Research Oct 2019Tooth germs undergo a series of dynamic morphologic changes through bud, cap, and bell stages, in which odontogenic epithelium continuously extends into the underlying...
Tooth germs undergo a series of dynamic morphologic changes through bud, cap, and bell stages, in which odontogenic epithelium continuously extends into the underlying mesenchyme. During the transition from the bud stage to the cap stage, the base of the bud flattens and then bends into a cap shape whose edges are referred to as "cervical loops." Although genetic mechanisms for cap formation have been well described, little is understood about the morphogenetic mechanisms. Computer modeling and cell trajectory tracking have suggested that the epithelial bending is driven purely by differential cell proliferation and adhesion in different parts of the tooth germ. Here, we show that, unexpectedly, inhibition of cell proliferation did not prevent bud-to-cap morphogenesis. We quantified cell shapes and actin and myosin distributions in different parts of the tooth epithelium at the critical stages and found that these are consistent with basal relaxation in the forming cervical loops and basal constriction around enamel knot at the center of the cap. Inhibition of focal adhesion kinase, which is required for basal constriction in other systems, arrested the molar explant morphogenesis at the bud stage. Together, these results show that the bud-to-cap transition is largely proliferation independent, and we propose that it is driven by classic actomyosin-driven cell shape-dependent mechanisms. We discuss how these results can be reconciled with the previous models and data.
Topics: Animals; Cell Proliferation; Female; Gene Expression Regulation, Developmental; Mesoderm; Mice; Molar; Morphogenesis; Odontogenesis; Pregnancy; Tooth Germ
PubMed: 31393749
DOI: 10.1177/0022034519869307 -
Clinical Oral Investigations Mar 2021Chronic rhinosinusitis (CRS) frequently stems from a dental origin, although odontogenic sinusitis (OS) remains underdiagnosed amongst different professionals. This...
OBJECTIVES
Chronic rhinosinusitis (CRS) frequently stems from a dental origin, although odontogenic sinusitis (OS) remains underdiagnosed amongst different professionals. This study aimed to explore how often odontogenic causes are considered when diagnosing CRS.
MATERIALS AND METHODS
Patient records from 374 new CRS patients treated at a tertiary-level ear, nose, and throat (ENT) clinic were selected. Entries and radiological reports were assessed exploring how often dentition was mentioned and OS was suspected, how often radiologists reported maxillary teeth, and how commonly typical OS microbial findings and unilateral symptoms occurred.
RESULTS
Although 10.1% of the CRS diagnoses were connected to possible dental issues, teeth were not mentioned for 73.8% of patients. Radiological reports were available from 267 computed or cone beam computed tomographies, of which 25.1% did not mention the maxillary teeth. The reported maxillary teeth pathology was not considered in 31/64 (48.4%) cases. Unilateral symptoms associated with apical periodontitis (OR = 2.49, 95% CI 1.27-4.89, p = 0.008). Microbial samples were available from 88 patients, for whom Staphylococcus aureus was the most common finding (17% of samples).
CONCLUSIONS
Odontogenic causes are often overlooked when diagnosing CRS. To provide adequate treatment, routine assessment of patient's dental history and status, careful radiograph evaluation, and utilization of microbial findings should be performed. Close cooperation with dentists is mandatory.
CLINICAL RELEVANCE
Dental professionals should be aware of difficulties medical professionals encounter when diagnosing possible OS. Thus, sufficient knowledge of OS pathology is essential to both medical and dental professionals.
Topics: Cone-Beam Computed Tomography; Humans; Maxillary Sinusitis; Odontogenesis; Sinusitis; Tomography, X-Ray Computed
PubMed: 32500403
DOI: 10.1007/s00784-020-03384-4 -
Virchows Archiv : An International... Sep 2021The nature of endometrial morular metaplasia (MorM) is still unknown. The nuclear β-catenin accumulation and the not rare ghost cell keratinization suggest a similarity... (Comparative Study)
Comparative Study
The nature of endometrial morular metaplasia (MorM) is still unknown. The nuclear β-catenin accumulation and the not rare ghost cell keratinization suggest a similarity with hard keratin-producing odontogenic and hair matrix tumors rather than with squamous differentiation. We aimed to compare MorM to hard keratin-producing tumors. Forty-one hard keratin-producing tumors, including 26 hair matrix tumors (20 pilomatrixomas and 6 pilomatrix carcinomas) and 15 odontogenic tumors (adamantinomatous craniopharyngiomas), were compared to 15 endometrioid carcinomas with MorM with or without squamous/keratinizing features. Immunohistochemistry for β-catenin, CD10, CDX2, ki67, p63, CK5/6, CK7, CK8/18, CK19, and pan-hard keratin was performed; 10 cases of endometrioid carcinomas with conventional squamous differentiation were used as controls. In adamantinomatous craniopharyngiomas, the β-catenin-accumulating cell clusters (whorl-like structures) were morphologically similar to MorM (round syncytial aggregates of bland cells with round-to-spindled nuclei and profuse cytoplasm), with overlapping squamous/keratinizing features (clear cells with prominent membrane, rounded squamous formations, ghost cells). Both MorM and whorl-like structures consistently showed positivity for CD10 and CDX2, with low ki67; cytokeratins pattern was also overlapping, although more variable. Hard keratin was focally/multifocally positive in 8 MorM cases and focally in one conventional squamous differentiation case. Hair matrix tumors showed no morphological or immunophenotypical overlap with MorM. MorM shows wide morphological and immunophenotypical overlap with the whorl-like structures of adamantinomatous craniopharyngiomas, which are analogous to enamel knots of tooth development. This suggests that MorM might be an aberrant mimic of odontogenic differentiation.
Topics: Biomarkers, Tumor; Carcinoma; Case-Control Studies; Cell Differentiation; Craniopharyngioma; Endometrial Neoplasms; Female; Humans; Immunohistochemistry; Keratins; Metaplasia; Odontogenesis; Pilomatrixoma; Pituitary Neoplasms; beta Catenin
PubMed: 33666744
DOI: 10.1007/s00428-021-03060-2