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Scientific Reports Feb 2016CLCN7 gene encodes the voltage gated chloride channel 7 (ClC-7) in humans. The mutations in CLCN7 have been associated with osteopetrosis in connection to the abnormal...
CLCN7 gene encodes the voltage gated chloride channel 7 (ClC-7) in humans. The mutations in CLCN7 have been associated with osteopetrosis in connection to the abnormal osteoclasts functions. Previously, we found that some osteopetrosis patients with CLCN7 mutations suffered from impacted teeth and root dysplasia. Here we set up two in vivo models under a normal or an osteoclast-poor environment to investigate how ClC-7 affects tooth development and tooth eruption. Firstly, chitosan-Clcn7-siRNA nanoparticles were injected around the first maxillary molar germ of newborn mice and caused the delay of tooth eruption and deformed tooth with root dysplasia. Secondly, E13.5 molar germs infected with Clcn7 shRNA lentivirus were transplanted under the kidney capsule and presented the abnormal changes in dentin structure, periodontal tissue and cementum. All these teeth changes have been reported in the patients with CLCN7 mutation. In vitro studies of ameloblasts, odontoblasts and dental follicle cells (DFCs) were conducted to explore the involved mechanism. We found that Clcn7 deficiency affect the differentiation of these cells, as well as the interaction between DFCs and osteoclasts through RANKL/OPG pathway. We conclude that ClC-7 may affect tooth development by directly targeting tooth cells, and regulate tooth eruption through DFC mediated osteoclast pathway.
Topics: Ameloblasts; Animals; Chitosan; Chloride Channels; Dentin; Humans; Mice; Mice, Inbred BALB C; Molar; Nanoparticles; Odontoblasts; Osteoclasts; RNA, Small Interfering; Tooth Eruption
PubMed: 26829236
DOI: 10.1038/srep19971 -
Journal of Dental Research Mar 2013Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development...
Root development and tooth eruption are very important topics in dentistry. However, they remain among the less-studied and -understood subjects. Root development accompanies rapid tooth eruption, but roots are required for the movement of teeth into the oral cavity. It has been shown that the dental follicle and bone remodeling are essential for tooth eruption. So far, only limited genes have been associated with root formation and tooth eruption. This may be due to the difficulties in studying late stages of tooth development and tooth movement and the lack of good model systems. Transgenic mice with eruption problems and short or no roots can be used as a powerful model for further deciphering of the cellular, molecular, and genetic mechanisms underlying root formation and tooth eruption. Better understanding of these processes can provide hints on delivering more efficient dental therapies in the future.
Topics: Animals; Odontoblasts; Tooth Eruption; Tooth Root; beta Catenin
PubMed: 23345536
DOI: 10.1177/0022034512474469 -
International Dental Journal Jun 2020Dental trauma and congenital anodontia are common causes of anodontia in the anterior maxilla. The proposed restorative treatment constitutes a challenge for many... (Review)
Review
INTRODUCTION
Dental trauma and congenital anodontia are common causes of anodontia in the anterior maxilla. The proposed restorative treatment constitutes a challenge for many dentists, particularly if it is a question of a young patient who has not yet completed skeletal and dental development. Current treatments for anterior maxillary anodontia include: fixed or removable partial dentures; orthodontic closure of interdental spaces; and dental implants. Dental implants do not move with the dento-alveolar complex during the growth period of the maxilla. Therefore, many researchers maintain that implants should be postponed until after adolescence, in order to prevent complications, such as infra-occlusion, that would require the replacement of the abutment and crown-implant restoration, or even invasive treatments, such as the removal of the implant in the future. The objective of this literature review is to investigate the aetiology of the phenomenon, and outcome.
RESULTS
Continuous tooth eruption is not affected by age, so considerable changes may occur due to eruption of adjacent teeth. In addition, both women and men are affected by this phenomenon and, usually, there is no significant difference in the amount of growth between the short face and the long face.
CONCLUSION
It can be concluded that continuous facial skeletal growth and teeth eruption are evident in the second and third decades. Where possible, it is advisable to delay placement of an anterior maxillary implant in the adolescent patient.
Topics: Adolescent; Crowns; Dental Implantation, Endosseous; Female; Humans; Incisor; Male; Maxilla; Tooth Eruption
PubMed: 32149398
DOI: 10.1111/idj.12549 -
Dental Press Journal of Orthodontics May 2019This study contributes to the understanding of the mechanisms associated with signs and symptoms of tooth eruption, by investigating the presence of mast cells in...
This study contributes to the understanding of the mechanisms associated with signs and symptoms of tooth eruption, by investigating the presence of mast cells in pericoronal tissues during the intraosseous (Group 1) and submucosal (Group 2) phases of eruption. We compared findings for these two groups with each other and with those for the oral mucosa (Group 3). In each group, 14 specimens were analyzed microscopically after hematoxylin and eosin staining and immunohistochemical analysis of c-Kit and tryptase expression. Results revealed that the number and density of mast cells is different in follicular tissues according to the eruption phase, which may mean that: 1) masticatory trauma of the oral mucosa and dental follicles in the submucosa may explain why reduced enamel epithelium exposes enamel to the cells of the connective tissue; 2) exposure of antigenic enamel proteins might correspond to the release of sequestered antigens, which may lead to the interaction of IgE and a greater number of mast cells in the region; and 3) the consequent degranulation and the local release of mediators, such as histamine, leukotrienes, prostaglandins, proteases, cytokines and growth factors, contribute to the understanding of signs and symptoms associated with tooth eruption.
Topics: Cell Count; Cytokines; Mast Cells; Tooth Eruption; Tryptases
PubMed: 31116282
DOI: 10.1590/2177-6709.24.2.020-031.oin -
The International Journal of... Feb 1995Tooth eruption is a localized process in the jaws which exhibits precise timing and bilateral symmetry. It involves resorption and formation of bone on opposite sides of... (Review)
Review
Tooth eruption is a localized process in the jaws which exhibits precise timing and bilateral symmetry. It involves resorption and formation of bone on opposite sides of the erupting tooth and these activities depend on the dental follicle, a thin connective tissue investment of the developing and erupting tooth. Biochemical studies have shown that during eruption cells, proteins and enzymes change in the dental follicle and several growth factors and proteins known to accelerate or retard eruption have been identified. This review discusses these aspects of tooth eruption and proposes testable hypotheses and strategies that can make studies of tooth eruption new experimental opportunities for developmental biologists.
Topics: Animals; Cell Differentiation; Dogs; Humans; Models, Biological; Molar; Tooth Eruption
PubMed: 7626410
DOI: No ID Found -
Scientific Reports May 2021We cryopreserved mouse tooth germs with widely open cervical margins of the enamel organ to overcome difficulties in cryoprotectant permeation and tested their efficacy...
We cryopreserved mouse tooth germs with widely open cervical margins of the enamel organ to overcome difficulties in cryoprotectant permeation and tested their efficacy by transplanting them into recipient mice. The upper right first molar germs of 8-day-old donor mice were extracted and categorized into the following four groups according to cryopreservation time: no cryopreservation, 1 week, 1 month, and 3 months. The donor tooth germs were transplanted into the upper right first molar germ sockets of the 8-day-old recipient mice. The upper left first molars of the recipient mice were used as controls. The outcome of the transplantation was assessed at 1, 2, and 3 weeks after transplantation. Stereomicroscopic evaluation revealed that most of the transplanted teeth erupted by 3 weeks after transplantation. Micro-computed tomography analysis revealed root elongation in the transplanted groups as well as in the controls. There was no significant difference between the cryopreserved and non-cryopreserved transplanted teeth, but the roots of the cryopreserved teeth were significantly shorter than those of the control teeth. Histological examination revealed root and periodontal ligament formations in all the transplanted groups. These results suggest that the transplantation of cryopreserved tooth germs facilitates subsequent root elongation and tooth eruption.
Topics: Alveolar Process; Animals; Cryopreservation; Enamel Organ; Maxilla; Mice; Mice, Inbred C57BL; Molar; Periodontal Ligament; Periodontium; Regeneration; Tooth Abnormalities; Tooth Eruption; Tooth Germ; Tooth Root; Tooth Socket; X-Ray Microtomography
PubMed: 33947923
DOI: 10.1038/s41598-021-88975-1 -
International Journal of Environmental... Aug 2022Persistent primary tooth (PPT) is a prevalent clinical condition that occurs when a primary tooth is over-retained beyond the established period of its normal...
Persistent primary tooth (PPT) is a prevalent clinical condition that occurs when a primary tooth is over-retained beyond the established period of its normal exfoliation time, remaining in the oral cavity. Many factors could be involved in the risk of PPT; therefore, the aim of this study was to evaluate if single nucleotide polymorphisms (SNPs) in the gene are associated with PPT. Children undergoing orthodontic treatment were screened. Orthopantomographs were assessed to evaluate PPT according to the Nolla stage of its permanent successor. The primary tooth was considered retained when its successor permanent tooth was in Nolla stage 8 and below the alveolar crypt, Nolla stage 9, or Nolla stage 10. A saliva sample from each child was collected and used for DNA extraction. A real-time PCR of two SNPs, rs689466 (-1195 G/A) and rs5275 (+665 T/C), was performed. A chi-square test was used to compare the allele and genotype distribution. Haplotype analysis was also performed. A total of 100 children were included in the study. Fifty-one had at least one PPT, while 49 children were classified as a control. The number of teeth persistent in the oral cavity ranged from 1 to 8. The genotype distribution was associated with PPT in the co-dominant model ( = 0.006) for SNP rs5275. The individuals that carry two T alleles (TT) compared with the individuals that carry at least one C allele (C + TC) had an almost three times higher chance of presenting with PPT ( = 0.012; OR = 2.99, CI95% 1.28 to 6.95-recessive model). The haplotype C-A for the SNPs rs5275 and rs689466, respectively, was significantly associated ( = 0.042). In conclusion, single nucleotide polymorphisms in the gene encoding for are associated with persistent primary tooth and may delay permanent tooth eruption.
Topics: Child; Cyclooxygenase 2; Dentition, Permanent; Humans; Polymorphism, Single Nucleotide; Tooth Eruption; Tooth, Deciduous
PubMed: 36011680
DOI: 10.3390/ijerph191610047 -
Journal of Anatomy Nov 2005Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics... (Review)
Review
Normal and abnormal jaw growth and tooth eruption are topics of great importance for several dental and medical disciplines. Thus far, clinical studies on these topics have used two-dimensional (2D) radiographic techniques. The purpose of the present study was to analyse normal mandibular growth and tooth eruption in three dimensions based on computer tomography (CT) scans, extending the principles of mandibular growth analysis proposed by Björk in 1969 from two to three dimensions. As longitudinal CT data from normal children are not available (for ethical reasons), CT data from children with Apert syndrome were employed, because it has been shown that the mandible in Apert syndrome is unaffected by the malformation, and these children often have several craniofacial CT scans performed during childhood for planning of cranial and midface surgery and for follow-up after surgery. A total of 49 datasets from ten children with Apert syndrome were available for study. The number of datasets from each individual ranged from three to seven. The first CT scan in each of the ten series was carried out before 1 year of age, and the ages for the 49 scans ranged from 1 week to 14.5 years. The mandible and the teeth were segmented and iso-surfaces generated. Landmarks were placed on the surface of the mandible, along the mandibular canals, the inner contour of the cortical plate at the lower border of the symphysis menti, and on the teeth. Superimposition of the mandibles in the longitudinal series was performed using the symphysis menti and the mandibular canals as suggested by Björk. The study supported the findings of stability of the symphysis menti and the mandibular canals as seen in profile view previously reported by Björk & Skieller in 1983. However, the mandibular canals were, actually, relocated laterally during growth. Furthermore, the position of tooth buds remained relatively stable inside the jaw until root formation started. Eruption paths of canines and premolars were vertical, whereas molars erupted in a lingual direction. The 3D method would seem to offer new insight into jaw growth and tooth eruption, but further studies are needed.
Topics: Acrocephalosyndactylia; Adolescent; Bicuspid; Child; Child, Preschool; Cuspid; Female; Humans; Imaging, Three-Dimensional; Infant; Longitudinal Studies; Male; Mandible; Molar; Tomography, X-Ray Computed; Tooth Eruption
PubMed: 16313399
DOI: 10.1111/j.1469-7580.2005.00479.x -
Acta Odontologica Latinoamericana : AOL Aug 2021Although it has been demonstrated that exposure of lactating rats to CrVI delays tooth eruption, the effects of CrVI exposure on bone remodeling in the developing...
Although it has been demonstrated that exposure of lactating rats to CrVI delays tooth eruption, the effects of CrVI exposure on bone remodeling in the developing alveolus during tooth eruption remain unknown. Our purpose was to analyze the effect of CrVI in the alveolus of the first lower molar of rats. Thirty-two suckling Wistar rats were divided into two groups. The experimental group received 12.5 mg/kg body weight/day of potassium dichromate dissolved in saline solution by oral gavage as of day 4 of the experiment; the control group received an equal dose of saline solution. Each group was divided into two sub-sets and euthanized at the ages of 9 and 15 days, respectively. Histochemical and histomorphometric studies of the bone surfaces of the developing tooth alveolus were performed. The percentage of bone formation surfaces was lower in experimental animals than in age-matched controls. The percentage of bone resorption surfaces was significantly lower in 9-day-old experimental rats than in controls and significantly higher in 15-day-old experimental rats than in controls. Exposure to CrVI during lactation alters the sequence of bone resorption and formation in the walls of the developing alveolus, both of which are necessary for tooth eruption, thus causing a delay.
Topics: Animals; Bone Remodeling; Chromium; Female; Lactation; Rats; Rats, Wistar; Tooth Eruption
PubMed: 34570855
DOI: 10.54589/aol.34/2/091 -
Journal of Dental Research Feb 2020Tooth eruption is a unique biological process by which highly mineralized tissues emerge into the outer world, and it occurs concomitantly with tooth root formation....
Tooth eruption is a unique biological process by which highly mineralized tissues emerge into the outer world, and it occurs concomitantly with tooth root formation. These 2 processes have been considered independent phenomena; however, recent studies support the theory that they are indeed intertwined. Dental mesenchymal progenitor cells in the dental follicle lie at the heart of the coupling of these 2 processes, providing a source for diverse mesenchymal cells that support formation of the highly functional tooth root and the periodontal attachment apparatus, while facilitating formation of osteoclasts. These cells are regulated by autocrine signaling by parathyroid hormone-related protein (PTHrP) and its parathyroid hormone/PTHrP receptor PPR. This PTHrP-PPR signaling appears to crosstalk with other signaling pathways and regulates proper cell fates of mesenchymal progenitor cell populations. Disruption of this autocrine PTHrP-PPR signaling in these cells leads to defective formation of the periodontal attachment apparatus, tooth root malformation, and failure of tooth eruption in molars, which essentially recapitulate primary failure of eruption in humans, a rare genetic disorder exclusively affecting tooth eruption. Diversity and distinct functionality of these mesenchymal progenitor cell populations that regulate tooth eruption and tooth root formation are beginning to be unraveled.
Topics: Humans; Mesenchymal Stem Cells; Osteoclasts; Parathyroid Hormone-Related Protein; Receptor, Parathyroid Hormone, Type 1; Tooth Eruption
PubMed: 31623502
DOI: 10.1177/0022034519882692