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Frontiers in Physiology 2022Enamel Renal Syndrome (ERS) is a rare genetic disorder caused by biallelic mutations in Family with sequence similarity 20A () gene encoding the secretory pathway...
Enamel Renal Syndrome (ERS) is a rare genetic disorder caused by biallelic mutations in Family with sequence similarity 20A () gene encoding the secretory pathway pseudokinase FAM20A. ERS is characterized by hypoplastic amelogenesis imperfecta (AI), impaired tooth eruption, intra-pulpal calcifications, gingival fibromatosis and nephrocalcinosis of various severity. Previous studies showed that the hypoplastic enamel was also hypomineralized but its chemical composition has not been extensively studied. Furthermore it is currently unclear whether dentinal defects are associated with AI in ERS patients. The objective of the study was to provide a structural and chemical analysis of enamel, dentin and dentin enamel junction (DEJ) in ERS patients carrying four, previously reported, distinct mutations in FAM20A. Chemical cartography obtained with Raman microscopy showed that compared to control samples, ERS enamel composition was severely altered and a cementum-like structure was observed in some cases. Chemical composition of peripulpal dentin was also affected and usual gradient of phosphate intensity, shown in DEJ profile, was absent in ERS samples. DEJ and dentinal anomalies were further confirmed by scanning electron microscopy analysis. In conclusion, our study shows that enamel formation is severely compromised in ERS patients and provides evidence that dentinal defects are an additional feature of the ERS dental phenotype.
PubMed: 36091358
DOI: 10.3389/fphys.2022.957110 -
Clinical Case Reports Aug 2022Amelogenesis imperfecta (AI) is a heterogeneous group of conditions characterized by inherited developmental defects of enamel. Patients with AI often have progressive...
Amelogenesis imperfecta (AI) is a heterogeneous group of conditions characterized by inherited developmental defects of enamel. Patients with AI often have progressive and severe loss of occlusal vertical dimensions (OVD), resulting in challenging dental rehabilitation. In this case report, we present the management of a 24-year-old male patient who previously underwent orthodontics, direct and indirect restorations, and continued to have progressive tooth wear. His vertical dimensions were restored in two phases, firstly with provisional restorations at the improved OVD, followed by a combination of monolithic zirconia and lithium disilicate full-coverage crowns. A removable acrylic appliance was then constructed to protect his teeth. This report emphasizes the importance of preserving and protecting the OVD from an early age to prevent more costly and complicated management in future.
PubMed: 36017113
DOI: 10.1002/ccr3.6135 -
Advances in Clinical and Experimental... Dec 2022Taurodontism is a morphological anomaly involving multirooted teeth that is characterized by a vertical shift of the pulp chamber and shortening of the roots. The... (Review)
Review
Taurodontism is a morphological anomaly involving multirooted teeth that is characterized by a vertical shift of the pulp chamber and shortening of the roots. The literature was analyzed to determine the impact of a diagnosis of taurodontism on dental treatment. A total of 85 full-text publications from the years 2005-2021 were analyzed and 20 publications were included in this research. The endodontic treatment of a taurodont tooth is challenging due to the apical displacement of the pulpal chamber floor and the incorrect configuration of the root canal system, or the presence of additional canals. In terms of prosthetics, the use of taurodont teeth as abutments is not recommended as they lack stability due to shorter roots. The extraction of taurodont teeth can be complicated due to an apical shift of the root furcation. In periodontology, taurodont teeth can have a better prognosis as there is less chance of furcation involvement. From an orthodontic point of view, it is important to note that taurodont teeth are not sufficiently embedded in the alveolus and have a greater tendency for root resorption. With regard to genetic diseases, it has been reported that this anomaly can exist as an isolated feature. However, the majority of authors agree that taurodontism is associated with conditions such as Down syndrome, Klinefelter syndrome, cleft lip and palate, hypodontia, amelogenesis imperfecta, and others. From a clinical standpoint, it is very important to diagnose taurodontism before treatment. A diagnosis of taurodontism can be important in the early diagnosis of malformations that commonly occur with this condition.
Topics: Humans; Dental Pulp Cavity; Cleft Lip; Cleft Palate; Tooth Abnormalities
PubMed: 36000881
DOI: 10.17219/acem/152120 -
Journal of Oral and Maxillofacial... 2022Amelogenesis imperfecta (AI) comprises a complicated group of conditions, involving a structural defect of the tooth enamel, owing to certain genetic disturbances. It is...
Amelogenesis imperfecta (AI) comprises a complicated group of conditions, involving a structural defect of the tooth enamel, owing to certain genetic disturbances. It is expressed as an autosomal dominant, autosomal recessive or X-linked recessive trait. The structural pattern and clinical appearances of all the teeth, including those in the deciduous as well as the permanent dentition, are affected. It may be differentiated into three main divisions such as hypoplastic, hypocalcific and hypomaturative patterns. Eruption of tooth refers to a complex coordinated physiological process characterized by the movement of a tooth from its initial developmental position within the jaws to its final functional position in the occlusal plane, dictated crucially by dental follicle, bony remodeling metabolic alteration and molecular determinants. Alteration involving any one of the factors might cause hindrances. Herein, we report two cases with AI associated with noneruption.
PubMed: 35968177
DOI: 10.4103/jomfp.JOMFP_471_20 -
European Archives of Paediatric... Dec 2022Amelogenesis imperfecta (AI) is a hereditary condition which affects the composition and structure of enamel in terms of hypoplasia and/or hypomineralization. The...
PURPOSE
Amelogenesis imperfecta (AI) is a hereditary condition which affects the composition and structure of enamel in terms of hypoplasia and/or hypomineralization. The condition severely affects patients facing such difficulties as hypersensibility, loss of tooth substance and poor aesthetics. The objective is to perform a systematic review of patient-reported outcome measures (PROMs) in patients with amelogenesis imperfecta.
METHODS
Inclusion criteria were articles written in English, including PROMs from patients with amelogenesis imperfecta. The databases PubMed, Scopus and Web of Science were searched on April 27, 2022, and eligible articles were screened. Exclusion criteria were articles based on proxy reports and single case reports.
RESULTS
405 studies were screened in terms of title and abstract, with 31 articles eligible for full-text screening, resulting in a total of 11 articles eligible for inclusion, (articles including 4-82 patients). The content was analyzed, resulting in the outcome divided into seven domains: Oral Health-Related Quality of Life (OHRQoL), Dental fear, Esthetics, Psychosocial factors, Function, Dental hypersensitivity, and Treatment outcome.
CONCLUSION
The limited quantity of research on PROMS from patients with AI indicates a significant impact of OHRQoL and daily life. A large variety of approaches have been presented in the articles. Patients report concerns of esthetics, hypersensitivity, function, and a general impact on well-being and social interaction. This highlights the importance for the need of early dental treatment.
PROSPERO REGISTRATION NUMBER
256875.
Topics: Humans; Amelogenesis Imperfecta; Quality of Life; Dental Enamel; Patient Reported Outcome Measures
PubMed: 35896941
DOI: 10.1007/s40368-022-00737-3 -
Genes Jul 2022Amelogenesis imperfecta (AI) is a heterogeneous group of genetic disorders of dental enamel. X-linked AI results from disease-causing variants in the AMELX gene. In this...
Amelogenesis imperfecta (AI) is a heterogeneous group of genetic disorders of dental enamel. X-linked AI results from disease-causing variants in the AMELX gene. In this paper, we characterise the genetic aetiology and enamel histology of female AI patients from two unrelated families with similar clinical and radiographic findings. All three probands were carefully selected from 40 patients with AI. In probands from both families, scanning electron microscopy confirmed hypoplastic and hypomineralised enamel. A neonatal line separated prenatally and postnatally formed enamel of distinctly different mineralisation qualities. In both families, whole exome analysis revealed the intron variant NM_182680.1: c.103-3T>C, located three nucleotides before exon 4 of the AMELX gene. In family I, an additional variant, c.2363G>A, was found in exon 5 of the FAM83H gene. This report illustrates a variant in the AMELX gene that was not previously reported to be causative for AI as well as an additional variant in the FAM83H gene with probably limited clinical significance.
Topics: Amelogenesis Imperfecta; Amelogenin; Exons; Female; Humans; Infant, Newborn; Introns; Mutation; Proteins
PubMed: 35886055
DOI: 10.3390/genes13071272 -
Genes & Diseases Sep 2022Formation of claudin-10 based tight junctions (TJs) is paramount to paracellular Na transport in multiple epithelia. Sequence variants in have been linked to HELIX...
Formation of claudin-10 based tight junctions (TJs) is paramount to paracellular Na transport in multiple epithelia. Sequence variants in have been linked to HELIX syndrome, a salt-losing tubulopathy with altered handling of divalent cations accompanied by dysfunctional salivary, sweat, and lacrimal glands. Here, we investigate molecular basis and phenotypic consequences of a newly identified homozygous variant that translates into a single amino acid substitution within the fourth transmembrane helix of claudin-10. In addition to hypohidrosis (H), electrolyte (E) imbalance with impaired urine concentrating ability, and hypolacrimia (L), phenotypic findings include altered salivary electrolyte composition and amelogenesis imperfecta but neither ichthyosis (I) nor xerostomia (X). Employing cellular TJ reconstitution assays, we demonstrate perturbation of - and -interactions between mutant claudin-10 proteins. Ultrastructures of reconstituted TJ strands show disturbed continuity and reduced abundance in the mutant case. Throughout, both major isoforms, claudin-10a and claudin-10b, are differentially affected with claudin-10b showing more severe molecular alterations. However, expression of the mutant in renal epithelial cells with endogenous TJs results in wild-type-like ion selectivity and conductivity, indicating that aberrant claudin-10 is generally capable of forming functional paracellular channels. Thus, mutant proteins prove pathogenic by compromising claudin-10 TJ strand assembly. Additional investigations indicate their insertion into TJs to occur in a tissue-specific manner.
PubMed: 35873018
DOI: 10.1016/j.gendis.2021.06.006 -
Matrix Biology : Journal of the... Aug 2022Amelogenesis imperfecta (AI) is an inherited developmental enamel defect affecting tooth masticatory function, esthetic appearance, and the well-being of patients. As...
Amelogenesis imperfecta (AI) is an inherited developmental enamel defect affecting tooth masticatory function, esthetic appearance, and the well-being of patients. As one of the major enamel matrix proteins (EMPs), enamelin (ENAM) has three serines located in Ser-x-Glu (S-x-E) motifs, which are potential phosphorylation sites for the Golgi casein kinase FAM20C. Defects in FAM20C have similarly been associated with AI. In our previous study of Enam mice, the Glu in the S-X-E motif was mutated into Gly, which was expected to cause a phosphorylation failure of Ser because Ser cannot be recognized by FAM20C. The severe enamel defects in ENAM mice reminiscent of Enam-knockout mouse enamel suggested a potentially important role of Ser phosphorylation in ENAM function. However, the enamel defects and ENAM dysfunction may also be attributed to distinct physicochemical differences between Glu and Gly. To clarify the significance of Ser phosphorylation to ENAM function, we generated two lines of Enam knock-in mice using CRISPR-Cas9 method to eliminate or mimic the phosphorylation state of Ser by substituting it with Ala or Asp (designated as S55A or S55D), respectively. The teeth of 6-day or 4-week-old mice were subjected to histology, micro-CT, SEM, TEM, immunohistochemistry, and mass spectrometry analyses to characterize the morphological, microstructural and proteomic changes in ameloblasts, enamel matrix and enamel rods. Our results showed that the enamel formation and EMP expression in S55D heterozygotes (Het) were less disturbed than those in S55A heterozygotes, while both homozygotes (Homo) had no mature enamel formation. Proteomic analysis revealed alterations of enamel matrix biosynthetic and mineralization processes in S55A Hets. Our present findings indicate that Asp substitution partially mimics the phosphorylation state of Ser in ENAM. Ser phosphorylation is essential for ENAM function during amelogenesis.
Topics: Amelogenesis; Amelogenesis Imperfecta; Animals; Calcium-Binding Proteins; Dental Enamel Proteins; Extracellular Matrix Proteins; Mice; Mice, Knockout; Phosphorylation; Proteomics; Serine
PubMed: 35820561
DOI: 10.1016/j.matbio.2022.07.001 -
Cureus May 2022Amelogenesis imperfecta (AI) refers to a group of inherited odontological disorders that alter enamel formation. The AI variant is based on the primary enamel defect,...
Amelogenesis imperfecta (AI) refers to a group of inherited odontological disorders that alter enamel formation. The AI variant is based on the primary enamel defect, classified as hypoplastic type I, hypo maturation type II, hypo calcification type III, and hypo maturation type IV. AI is commonly linked with the loss of the normal occlusal plane, the loss of the vertical dimension of occlusion (VDO), and impaired functions and esthetics. This case report describes the Hobo and Takayama twin-stage procedure for the rehabilitation of a patient with hypoplastic AI.
PubMed: 35800841
DOI: 10.7759/cureus.25512 -
International Journal of Paediatric... Nov 2022Amelogenesis imperfecta (AI) is an inherited disorder of enamel development that is challenging to treat and often associated with negative patient and parental...
BACKGROUND
Amelogenesis imperfecta (AI) is an inherited disorder of enamel development that is challenging to treat and often associated with negative patient and parental outcomes. Social media provides a valuable perspective on patients' and dental professionals' experience of AI and dental care.
AIM
To explore how the public and dental professionals use social media to discuss AI.
DESIGN
A cross-sectional study involving a systemic search of eight social media platforms using the search term 'amelogenesis imperfecta'. Relevant posts were selected using predefined eligibility criteria. Word content of eligible posts was qualitatively analysed using a thematic framework approach.
RESULTS
A total of 555 posts were identified, of which 144 were eligible for analysis. For dental professionals, the posts included case reports and seeking and sharing of information. For the public, the posts were related to individuals' experience of AI, dental treatment and outcome of treatment.
CONCLUSIONS
Posts from individuals affected by AI suggest a need for better distribution of reliable information and greater support. Case reports indicate that dental professionals find it challenging to recognise AI and determine appropriate treatment options. Social media could potentially be used to inform and support people with AI and allow dental professionals to share information and learning with peers.
Topics: Amelogenesis; Amelogenesis Imperfecta; Cross-Sectional Studies; Dentists; Humans; Social Media
PubMed: 35771161
DOI: 10.1111/ipd.13015