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Trends in Molecular Medicine May 2021Tooth defects are an extremely common health condition that affects millions of individuals. Currently used dental repair treatments include fillings for caries,... (Review)
Review
Tooth defects are an extremely common health condition that affects millions of individuals. Currently used dental repair treatments include fillings for caries, endodontic treatment for pulp necrosis, and dental implants to replace missing teeth, all of which rely on the use of synthetic materials. By contrast, the fields of tissue engineering and regenerative medicine and dentistry (TERMD) use biologically based therapeutic strategies for vital tissue regeneration, and thus have the potential to regenerate living tissues. Methods to create bioengineered replacement teeth benefit from a detailed understanding of the molecular signaling networks regulating natural tooth development. We discuss how key signaling pathways regulating natural tooth development are being exploited for applications in TERMD approaches for vital tooth regeneration.
Topics: Humans; Odontogenesis; Regenerative Medicine; Signal Transduction; Stem Cells; Tissue Engineering; Tissue Scaffolds; Tooth; Tooth Germ
PubMed: 33781688
DOI: 10.1016/j.molmed.2021.02.005 -
Gerontology 2018The tooth is an intricate composition of precisely patterned, mineralized matrices and soft tissues. Mineralized tissues include enamel (produced by the epithelial cells... (Review)
Review
The tooth is an intricate composition of precisely patterned, mineralized matrices and soft tissues. Mineralized tissues include enamel (produced by the epithelial cells called ameloblasts), dentin and cementum (produced by mesenchymal cells called odontoblasts and cementoblasts, respectively), and soft tissues, which include the dental pulp and the periodontal ligament along with the invading nerves and blood vessels. It was perceived for a very long time that teeth primarily serve an esthetical function. In recent years, however, the role of healthy teeth, as well as the impact of oral health on general well-being, became more evident. Tooth loss, caused by tooth decay, congenital malformations (tooth agenesis), trauma, periodontal diseases, or age-related changes, is usually replaced by artificial materials which lack many of the important biological characteristics of the natural tooth. Human teeth have very low to almost absent regeneration potential, due to early loss of cell populations with regenerative capacity, namely stem cells. Significant effort has been made in recent decades to identify and characterize tooth stem cells, and to unravel the developmental programs which these cells follow in order to generate a tooth.
Topics: Aging; Animals; Epithelial-Mesenchymal Transition; Humans; Models, Biological; Odontogenesis; Regeneration; Stem Cell Niche; Tooth
PubMed: 29533942
DOI: 10.1159/000486592 -
Progress in Orthodontics Jan 2023The present study was designed to define: (1) which are the less predictable OTM with Invisalign aligners when the treatment plan is designed by expert operators, (2) if...
BACKGROUNDS
The present study was designed to define: (1) which are the less predictable OTM with Invisalign aligners when the treatment plan is designed by expert operators, (2) if the presence and shape of attachments influence the predictability of OTM and (3) if patients' demographics influence OTM predictability. The sample comprises 79 prospectively recruited patients (mean age 30.8 years; SD 12.0; 23 M, 56 F), treated by expert operators with an average of 27 aligners (SD 15) in the maxillary arch and 25 aligners (SD 11) in the mandibular arch. Post-treatment digital models and final virtual treatment plan models were exported from ClinCheck software as STL files and subsequently imported into Geomagic Qualify software, to compare final teeth positions. The differences were calculated and tested for statistical significance for each tooth in the mesial-distal, vestibular-lingual and occlusal-gingival directions, as well as for angulation, inclination and rotation. In addition, the statistical significance of categorical variables was tested.
RESULTS
The lack of correction was significant for all movements and in all group of teeth (P < 0.01) except for the rotation of maxillary first molar. The prescribed OTM, the group of teeth and movement, the frequency of aligner change and the use of attachment influence the outcome. The greatest discrepancies in predicted and achieved tooth position were found for angular movements and rotation of teeth characterized by round-shaped crowns, for a ratio of approximately 0.4° per 1° prescribed. Optimized attachments for upper canines and lower premolar rotation seem not working properly. Second molar movements are mostly unexpressed. Furthermore, changing the aligner every 14 days will reduce the lack of correction of the 12% with respect to 7 days aligner change.
CONCLUSIONS
Predictability of orthodontic movement with aligners still has limitations related to the biomechanics of the system: the shape of some attachments and the characteristics of aligner material need to be redefined. However, the results of this study allow to properly design the virtual treatment plan, revealing how much overcorrection is needed and which attachments are most effective.
Topics: Tooth Movement Techniques; Software; Orthodontic Appliances, Removable; Molar; Bicuspid
PubMed: 36642743
DOI: 10.1186/s40510-022-00453-0 -
Head & Face Medicine Mar 2018Primary failure of eruption (PFE) is a rare disease defined as incomplete tooth eruption despite the presence of a clear eruption pathway. Orthodontic extrusion is not...
BACKGROUND
Primary failure of eruption (PFE) is a rare disease defined as incomplete tooth eruption despite the presence of a clear eruption pathway. Orthodontic extrusion is not feasible in this case because it results in ankylosis of teeth. To the best of our knowledge, besides the study of Ahmad et al. (Eur J Orthod 28:535-540, 2006), no study has systematically analysed the clinical features of and factors associated with PFE. Therefore, the aim of this study was to systematically evaluate the current literature (from 2006 to 2017) for new insights and developments on the aetiology, diagnosis, genetics, and treatment options of PFE.
METHODS
Following the PRISMA guidelines, a systematic search was performed using the PubMed/Medline database for studies reporting on PFE. The following terms were used: "primary failure of tooth eruption", "primary failure of eruption", "tooth eruption failure", and "PFE".
RESULTS
Overall, 17 articles reporting clinical data of 314 patients were identified. In all patients, the molars were affected. In 81 reported cases, both the molars and the premolars were affected by PFE. Further, 38 patients' primary teeth were also affected. In 27 patients, no family members were affected. Additional dental anomalies were observed in 39 patients. A total of 51 different variants of the PTH1R gene associated with PFE were recorded.
CONCLUSIONS
Infraocclusion of the posterior teeth, especially if both sides are affected, is the hallmark of PFE. If a patient is affected by PFE, all teeth distal to the most mesial tooth are also affected by PFE. Primary teeth can also be impacted; however, this may not necessarily occur. If a patient is suspected of having PFE, a genetic test for mutation in the PTH1R gene should be recommended prior to any orthodontic treatment to avoid ankylosis. Treatment options depend on the patient's age and the clinical situation, and they must be evaluated individually.
Topics: Age Factors; Bicuspid; Child, Preschool; Female; Follow-Up Studies; Humans; Infant; Male; Molar; Orthodontic Extrusion; Radiography, Panoramic; Sex Factors; Tooth Ankylosis; Tooth Eruption; Tooth, Deciduous; Tooth, Unerupted
PubMed: 29544499
DOI: 10.1186/s13005-018-0163-7 -
Nature Communications Sep 2020Understanding cell types and mechanisms of dental growth is essential for reconstruction and engineering of teeth. Therefore, we investigated cellular composition of...
Understanding cell types and mechanisms of dental growth is essential for reconstruction and engineering of teeth. Therefore, we investigated cellular composition of growing and non-growing mouse and human teeth. As a result, we report an unappreciated cellular complexity of the continuously-growing mouse incisor, which suggests a coherent model of cell dynamics enabling unarrested growth. This model relies on spatially-restricted stem, progenitor and differentiated populations in the epithelial and mesenchymal compartments underlying the coordinated expansion of two major branches of pulpal cells and diverse epithelial subtypes. Further comparisons of human and mouse teeth yield both parallelisms and differences in tissue heterogeneity and highlight the specifics behind growing and non-growing modes. Despite being similar at a coarse level, mouse and human teeth reveal molecular differences and species-specific cell subtypes suggesting possible evolutionary divergence. Overall, here we provide an atlas of human and mouse teeth with a focus on growth and differentiation.
Topics: Adolescent; Adult; Animals; Cell Differentiation; Epithelial Cells; Female; Gene Expression Regulation, Developmental; Genetic Heterogeneity; Humans; Incisor; Male; Mesoderm; Mice; Mice, Inbred C57BL; Models, Animal; Molar; Odontoblasts; Stem Cells; Tooth; Young Adult
PubMed: 32968047
DOI: 10.1038/s41467-020-18512-7 -
Australian Dental Journal Dec 2019The extraction of permanent molar teeth was first introduced in 1976 as a substitution for premolar extraction in cases with mild crowding. Since then, a number of... (Review)
Review
The extraction of permanent molar teeth was first introduced in 1976 as a substitution for premolar extraction in cases with mild crowding. Since then, a number of studies have investigated the effect of permanent molar extraction on dentofacial harmony. Undertaking the procedure of molar extraction is most commonly recommended in response to factors such as: gross caries, large restorations and root-filled teeth, along with its application in the management of anterior open bite and reduction in crowding in facial regions. It has been indicated, however, that before undertaking the extraction of molar teeth it is important to investigate the potential influence of the procedure on other molars, with particular consideration of their eruption path. This is due to the doubt as to the effect of the exact molar teeth extraction and their consequences. In light of this, This review was undertaken to investigate and compare the effect of first, second and the third molar teeth extraction and their subsequent dentofacial complex changes.
Topics: Bicuspid; Humans; Molar; Molar, Third; Tooth Eruption; Tooth Extraction
PubMed: 31465537
DOI: 10.1111/adj.12716 -
TheScientificWorldJournal 2014Tissue engineering is a growing field. In the near future, it will probably be possible to generate a complete vital tooth from a single stem cell. Pulp... (Review)
Review
Tissue engineering is a growing field. In the near future, it will probably be possible to generate a complete vital tooth from a single stem cell. Pulp revascularization is dependent on the ability of residual pulp and apical and periodontal stem cells to differentiate. These cells have the ability to generate a highly vascularized and a conjunctive rich living tissue. This one is able to colonize the available pulp space. Revascularization is a new treatment method for immature necrotic permanent teeth. Up to now, apexification procedures were applied for these teeth, using calcium dihydroxide or MTA to produce an artificial apical barrier. However, the pulp revascularization allows the stimulation of the apical development and the root maturation of immature teeth. Two pulp revascularization techniques are used in the literature, one using calcium dihydroxide and the second using a triple antibiotic paste. Based on these two different pulp revascularization protocols, which obtain the desired therapeutic success, the literature will be reviewed and analyzed according to the relevance of their choice of materials. Based on the literature, we propose a new relevant protocol and a new mixture of antibiotics.
Topics: Apexification; Calcium Hydroxide; Clinical Protocols; Dental Pulp; Humans; Root Canal Filling Materials; Root Canal Therapy; Tissue Engineering; Tooth
PubMed: 25383384
DOI: 10.1155/2014/737503 -
Stem Cell Research & Therapy Mar 2017Experiments have previously demonstrated the therapeutic potential of mobilized dental pulp stem cells (MDPSCs) for complete pulp regeneration. The aim of the present...
BACKGROUND
Experiments have previously demonstrated the therapeutic potential of mobilized dental pulp stem cells (MDPSCs) for complete pulp regeneration. The aim of the present pilot clinical study is to assess the safety, potential efficacy, and feasibility of autologous transplantation of MDPSCs in pulpectomized teeth.
METHODS
Five patients with irreversible pulpitis were enrolled and monitored for up to 24 weeks following MDPSC transplantation. The MDPSCs were isolated from discarded teeth and expanded based on good manufacturing practice (GMP). The quality of the MDPSCs at passages 9 or 10 was ascertained by karyotype analyses. The MDPSCs were transplanted with granulocyte colony-stimulating factor (G-CSF) in atelocollagen into pulpectomized teeth.
RESULTS
The clinical and laboratory evaluations demonstrated no adverse events or toxicity. The electric pulp test (EPT) of the pulp at 4 weeks demonstrated a robust positive response. The signal intensity of magnetic resonance imaging (MRI) of the regenerated tissue in the root canal after 24 weeks was similar to that of normal dental pulp in the untreated control. Finally, cone beam computed tomography demonstrated functional dentin formation in three of the five patients.
CONCLUSIONS
Human MDPSCs are safe and efficacious for complete pulp regeneration in humans in this pilot clinical study.
Topics: Adult; Cell Differentiation; Cell Proliferation; Dental Pulp; Female; Granulocyte Colony-Stimulating Factor; Humans; Magnetic Resonance Imaging; Male; Pulpitis; Regeneration; Stem Cell Transplantation; Stem Cells; Tooth
PubMed: 28279187
DOI: 10.1186/s13287-017-0506-5 -
Journal of Tissue Engineering and... Sep 2017Bio-engineered teeth that can grow and remodel in a manner similar to that of natural teeth have the potential to serve as permanent replacements to the currently used... (Review)
Review
Bio-engineered teeth that can grow and remodel in a manner similar to that of natural teeth have the potential to serve as permanent replacements to the currently used prosthetic teeth, such as dental implants. A major challenge in designing functional bio-engineered teeth is to mimic both the structural and anisotropic mechanical characteristics of the native tooth. Therefore, the field of dental and whole tooth regeneration has advanced towards the molecular and nanoscale design of bio-active, biomimetic systems, using biomaterials, drug delivery systems and stem cells. The focus of this review is to discuss recent advances in tooth tissue engineering, using biomimetic scaffolds that provide proper architectural cues, exhibit the capacity to support dental stem cell proliferation and differentiation and sequester and release bio-active agents, such as growth factors and nucleic acids, in a spatiotemporal controlled manner. Although many in vitro and in vivo studies on tooth regeneration appear promising, before tooth tissue engineering becomes a reality for humans, additional research is needed to perfect methods that use adult human dental stem cells, as opposed to embryonic dental stem cells, and to devise the means to generate bio-engineered teeth of predetermined size and shape. Copyright © 2016 John Wiley & Sons, Ltd.
Topics: Animals; Biomimetics; Cell Differentiation; Cell Proliferation; Drug Delivery Systems; Humans; Stem Cell Transplantation; Stem Cells; Tissue Engineering; Tooth
PubMed: 27151766
DOI: 10.1002/term.2134 -
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