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Revista Cientifica Odontologica... 2023The main origin of amelogenesis imperfecta (AI) is a genetic alteration inherited by a family member which affects the dental enamel of the teeth of a person with this...
The main origin of amelogenesis imperfecta (AI) is a genetic alteration inherited by a family member which affects the dental enamel of the teeth of a person with this condition in various ways. The present clinical case from the Teaching Dental Clinic of the Peruvian University Cayetano Heredia is of a 6-year 5-month-old male child who came to the dental office accompanied by his father and 8-year-old sister, diagnosed with the same AI condition. The comprehensive treatment proposed for this patient was determined by radiographic and clinical examinations and consultations with specialists in different areas. The purpose of this publication was to report a case and describe possible clinical approaches.
PubMed: 38288452
DOI: 10.21142/2523-2754-1102-2023-156 -
Frontiers in Physiology 2023Developmental defects of the enamel manifest before tooth eruption and include amelogenesis imperfecta, a rare disease of underlying gene mutations, and molar-incisor...
Developmental defects of the enamel manifest before tooth eruption and include amelogenesis imperfecta, a rare disease of underlying gene mutations, and molar-incisor hypomineralization (MIH), a prevalent disease in children originating from environmental and epigenetic factors. MIH enamel presents as the abnormal enamel marked by loss of translucency, demarcation between the healthy and affected enamel, and reduced mineral content. The pathophysiology of opaque, demarcated enamel lesions is not understood; however, the retention of enamel proteins in the matrix has been suggested. Ameloblastin (Ambn) is an enamel protein of the secreted calcium-binding phosphoproteins (SCPPs) critical for enamel formation. When the gene is mutated or deleted, teeth are affected by hypoplastic amelogenesis imperfecta. In this study, enamel formation in mice was analyzed when transgenic was overexpressed from the amelogenin promoter encoding full-length Ambn. was under- and overexpressed at six increasing concentrations in separate mouse lines. Mice overexpressing displayed opaque enamel at low concentrations and demarcated lesions at high concentrations. The severity of enamel lesions increased starting from the inner enamel close to the dentino-enamel junction (DEJ) to span the entire width of the enamel layer in demarcated areas. Associated with the opaque enamel were 17-kDa Ambn cleavage products, a prolonged secretory stage, and a thin basement membrane in the maturation stage. Ambn accumulations found in the innermost enamel close to the DEJ and the mineralization front correlated with reduced mineral content. Demarcated enamel lesions were associated with Ambn species of 17 kDa and higher, prolonged secretory and transition stages, a thin basement membrane, and shortened maturation stages. Hypomineralized opacities were delineated against the surrounding mineralized enamel and adjacent to ameloblasts detached from the enamel surface. Inefficient Ambn cleavage, loss of contact between ameloblasts, and the altered basement membrane curtailed the endocytic activity; thus, enamel proteins remained unresorbed in the matrix. Ameloblasts have the ability to distinguish between Ambn concentration and Ambn cleavage products through finely tuned feedback mechanisms. The under- or overexpression of Ambn in murine secretory ameloblasts results in either hypoplastic amelogenesis imperfecta or hypomineralization with opaque or sharply demarcated boundaries of lesions, similar to MIH.
PubMed: 38274050
DOI: 10.3389/fphys.2023.1233391 -
Iranian Journal of Biotechnology Oct 2023Dental enamel formation is a complex process that is regulated by various genes. One such gene, Family With Sequence Similarity 83 Member H (Fam83h), has been identified...
BACKGROUND
Dental enamel formation is a complex process that is regulated by various genes. One such gene, Family With Sequence Similarity 83 Member H (Fam83h), has been identified as an essential factor for dental enamel formation. Additionally, Fam83h has been found to be potentially linked to the Wnt/β-catenin pathway.
OBJECTIVES
This study aimed to investigate the effects of the Fam83h knockout gene on mineralization and formation of teeth, along with mediators of the Wnt/β-catenin pathway as a development aspect in mice.
MATERIALS AND METHODS
To confirm the Fam83h-KnockOut mice, both Sanger sequencing and Western blot methods were used. then used qPCR to measure the expression levels of genes related to tooth mineralization and formation of dental root, including Fam20a, Dspp, Dmp1, Enam, Ambn, Sppl2a, Mmp20, and Wnt/β-catenin pathway mediators, in both the Fam83h-Knockout and wild-type mice at 5, 11 and 18 days of age. also the expression level of Fgf10 and mediators of the Wnt/β-catenin pathway was measured in the skin of both Knockout and wild-type mice using qPCR. A histological assessment was then performed to further investigate the results.
RESULTS
A significant reduction in the expression levels of Ambn, Mmp20, Dspp, and Fgf10 in the dental root of Fam83h-Knockout mice compared to their wild-type counterparts was demonstrated by our results, indicating potential disruptions in tooth development. Significant down-regulation of CK1a, CK1e, and β-catenin in the dental root of Fam83h-Knockout mice was associated with a reduction in mineralization and formation-related gene. Additionally, the skin analysis of Fam83h-Knockout mice revealed reduced levels of Fgf10, CK1a, CK1e, and β-catenin. Further histological assessment confirmed that the concurrent reduction of Fgf10 expression level and Wnt/β-catenin genes were associated with alterations in hair follicle maturation.
CONCLUSIONS
The concurrent reduction in the expression level of both Wnt/β-catenin mediators and mineralization-related genes, resulting in the disruption of dental mineralization and formation, was caused by the deficiency of Fam83h. Our findings suggest a cumulative effect and multi-factorial interplay between Fam83h, Wnt/Β-Catenin signaling, and dental mineralization-related genes subsequently, during the dental formation process.
PubMed: 38269199
DOI: 10.30498/ijb.2023.391902.3673 -
Journal of Esthetic and Restorative... Jun 2024The aim of this review was to compare various types of restorations used in children and young adults affected with amelogenesis imperfecta (AI) to determine the most... (Review)
Review
OBJECTIVE
The aim of this review was to compare various types of restorations used in children and young adults affected with amelogenesis imperfecta (AI) to determine the most effective restorative treatment.
METHODS
This systematic review included randomized controlled trials, retrospective and prospective cohorts conducted on children and young adults diagnosed with amelogenesis imperfecta and written in French or English. A systematic search was conducted using four databases, namely Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE via PubMed, Science Direct and Scopus, using a selection of MeSH terms: "Amelogenesis Imperfecta," "Therapeutics," "Treatment Outcome," "Adult, young," "Child," "Dental Restoration, Permanent," "Dental Restoration, Temporary," and "Esthetics, Dental."
RESULTS
Out of 138 articles identified in the initial search, four articles met all the inclusion criteria. The results showed that ceramic restorations had better quality scores and longevity compared to other restorations.
CONCLUSION
Ceramic restorations could be considered the restorative treatment modality of choice for AI-affected children and young adults. However, more high-quality clinical trials involving young patients affected with AI are required to evaluate and compare the outcomes of different restorative approaches.
CLINICAL SIGNIFICANCE
Young patients affected with amelogenesis imperfecta usually suffer from low self-esteem, psychological problems and social avoidance, caused by the alteration of teeth such as discoloration, sensitivity, fractures and reduced size. For the dentist, selecting the appropriate restorative treatment for AI in young patients could be a veritable challenge. Therefore, it is important to have an evidence-based modality. For this reason, in this review, the different restorative approaches used in AI-affected young patients were compared to recommend the most effective treatment.
Topics: Humans; Amelogenesis Imperfecta; Child; Dental Restoration, Permanent; Young Adult; Adolescent
PubMed: 38258433
DOI: 10.1111/jerd.13191 -
Heliyon Jan 2024Brachyolmia is a heterogeneous group of developmental disorders characterized by a short trunk, short stature, scoliosis, and generalized platyspondyly without...
Brachyolmia is a heterogeneous group of developmental disorders characterized by a short trunk, short stature, scoliosis, and generalized platyspondyly without significant deformities in the long bones. DASS (Dental Abnormalities and Short Stature), caused by alterations in the gene, was previously considered as a subtype of brachyolmia. The present study investigated three unrelated consanguineous families (A, B, C) with Brachyolmia and DASS from Egypt and Pakistan. In our Egyptian patients, we also observed hearing impairment. Exome sequencing was performed to determine the genetic causes of the diverse clinical conditions in the patients. Exome sequencing identified a novel homozygous splice acceptor site variant (:c.3629-1G > T; p. ?) responsible for DASS phenotypes and a known homozygous missense variant (: c.590T > C; p.Ile197Thr) causing hearing impairment in the Egyptian patients. In addition, two previously reported homozygous frameshift variants (:c.132delG; p.Pro45Argfs*25) and (:c.2216delG; p.Gly739Alafs*7) were identified in Pakistani patients. This study emphasizes the vital role of in the axial skeleton and tooth morphogenesis and expands the mutational spectrum of . We are reporting variants in seven patients of three families, majorly causing brachyolmia with dental and cardiac anomalies. Skeletal assessment documented short webbed neck, broad chest, evidences of mild long bones involvement, short distal phalanges, pes planus and osteopenic bone texture as additional associated findings expanding the clinical phenotype of DASS. The current study reveals that the hearing impairment phenotype in Egyptian patients of family A has a separate transmission mechanism independent of .
PubMed: 38192829
DOI: 10.1016/j.heliyon.2023.e23688 -
Heliyon Jan 2024Amelogenesis imperfecta is a rare genetic disorder that interferes with normal enamel formation. Of the 4 main types of amelogenesis imperfecta, hypoplastic (type 1) is...
Amelogenesis imperfecta is a rare genetic disorder that interferes with normal enamel formation. Of the 4 main types of amelogenesis imperfecta, hypoplastic (type 1) is the most prevalent, characterized by a quantitative alteration in enamel. The pitting or reduced thickness of the enamel results in generalized hypersensitivity, increased susceptibility to caries and infection, attrition, and a loss in vertical dimension of occlusion. Prosthodontic management of these patients can be challenging not only functionally and restoratively, but also from an emotional and psychosocial standpoint. This clinical report describes the prosthodontic management and rehabilitation of two young adult siblings with hypoplastic (type 1) amelogenesis imperfecta.
PubMed: 38192821
DOI: 10.1016/j.heliyon.2023.e23939 -
Cureus Dec 2023Amelogenesis imperfecta (AI) is a rare genetic disorder affecting children and adults. Knowledge about AI is limited to clinical representation and radiographical... (Review)
Review
Amelogenesis imperfecta (AI) is a rare genetic disorder affecting children and adults. Knowledge about AI is limited to clinical representation and radiographical findings. Various treatments are provided to children with AI, yet no definitive treatment guideline has been suggested in the literature. This scoping review highlights the knowledge of the etiology and classification of AI and synthesizes these findings in a comprehensive review, focusing mainly on the various forms of AI in children and management with a restorative conservative approach. Five electronic databases, namely, PubMed, Google Scholar, Embase, Web of Science, and Scopus, were searched for the relevant articles. The search was performed in two phases: first for title and abstract, and second for full-text articles. The studies included in this scoping review were published from 2013 to August 2023. The data extraction was done on a customized sheet. A total of 33 studies were included in this review, of which 19 were reports and series, seven were observational, and seven were reviews. Most patients included in this review suffered from the hypoplastic type of AI (54%), followed by hypomatured (36%), and hypocalcified (10%). The treatment modalities explained were divided into the following three phases: temporary, transient, and permanent. Almost all included reports suggested the requirement for guidelines for treating AI among young children. This scoping review suggests the need for guidelines for treating AI in children. Moreover, pediatric dentists should prioritize early diagnosis and treatment and long-term follow-up for AI in children to effectively enhance the patient's psychological well-being and overall quality of life.
PubMed: 38179349
DOI: 10.7759/cureus.49968 -
Cureus Dec 2023Odontogenic anomalies encompass deviations in dental morphology, orientation, or spatial positioning within the mandibular structures. This study probed the frequency of...
BACKGROUND
Odontogenic anomalies encompass deviations in dental morphology, orientation, or spatial positioning within the mandibular structures. This study probed the frequency of such dental malformations among orthodontic patients receiving treatment in Riyadh City, Saudi Arabia. Furthermore, the study sought to discern variations in the manifestation of these dental anomalies related to gender and nationality.
MATERIALS AND METHODS
A retrospective analysis was conducted on 384 panoramic radiographs belonging to orthodontic patients (comprising 222 males and 162 females) who sought treatment at orthodontic clinics of a privately owned university hospital in Riyadh City between 2017 and 2019. The patient records were scrutinized for various dental abnormalities, including but not limited to dilacerated teeth, supernumerary teeth, congenital absence of teeth, impactions, hyperdontia, hypodontia, taurodontism, tooth rotation, and amelogenesis imperfecta. The Chi-square test was employed to assess the correlation between the prevalence of dental anomalies and variables such as gender and nationality. A p-value of less than 0.05 was deemed statistically significant for all tests.
RESULTS
Among the assessed sample size of orthodontic patients, dental impactions emerged as the most prevalent dental anomaly, affecting 246 patients (64.1%). This was followed by the occurrence of supernumerary teeth in 31 patients (8.1%), hyperdontia in 29 patients (7.6%), and congenital absence of teeth in 28 patients (7.3%). Other less frequently observed dental irregularities included dilacerated teeth in 23 patients (6%), amelogenesis imperfecta in 12 patients (3.1%), taurodontism in 12 patients (3.1%), and tooth rotations in five patients (1.3%). A statistically significant gender-based disparity was observed, with dental impactions being more prevalent among males (n=154; 69.4%) than females (n=92; 56.8%). Conversely, supernumerary teeth were more prevalent among females (n=24; 14.8%) than males (n=7; 3.2%). No significant variation in the prevalence of dental anomalies was discernible across different nationalities.
CONCLUSION
Impactions and the presence of supernumerary teeth were the predominant dental anomalies detected among the studied orthodontic patient population. The prevalence of dental anomalies exhibited discernible variations based on gender but not nationality. These disparities could potentially influence orthodontic outcomes, underscoring the necessity for meticulous examination and tailored orthodontic treatment planning.
PubMed: 38174162
DOI: 10.7759/cureus.49893 -
Scientific Reports Jan 2024Kohlschütter-Tönz syndrome (KTS) is a rare autosomal recessive disorder characterized by severe intellectual disability, early-onset epileptic seizures, and...
Kohlschütter-Tönz syndrome (KTS) is a rare autosomal recessive disorder characterized by severe intellectual disability, early-onset epileptic seizures, and amelogenesis imperfecta. Here, we present a novel Rogdi mutant mouse deleting exons 6-11- a mutation found in KTS patients disabling ROGDI function. This Rogdi mutant model recapitulates most KTS symptoms. Mutants displayed pentylenetetrazol-induced seizures, confirming epilepsy susceptibility. Spontaneous locomotion and circadian activity tests demonstrate Rogdi mutant hyperactivity mirroring patient spasticity. Object recognition impairment indicates memory deficits. Rogdi mutant enamel was markedly less mature. Scanning electron microscopy confirmed its hypomineralized/hypomature crystallization, as well as its low mineral content. Transcriptomic RNA sequencing of postnatal day 5 lower incisors showed downregulated enamel matrix proteins Enam, Amelx, and Ambn. Enamel crystallization appears highly pH-dependent, cycling between an acidic and neutral pH during enamel maturation. Rogdi teeth exhibit no signs of cyclic dental acidification. Additionally, expression changes in Wdr72, Slc9a3r2, and Atp6v0c were identified as potential contributors to these tooth acidification abnormalities. These proteins interact through the acidifying V-ATPase complex. Here, we present the Rogdi mutant as a novel model to partially decipher KTS pathophysiology. Rogdi mutant defects in acidification might explain the unusual combination of enamel and rare neurological disease symptoms.
Topics: Humans; Animals; Mice; Amelogenesis Imperfecta; Epilepsy; Dementia; Seizures; Mutation; Tooth Abnormalities; Membrane Proteins; Nuclear Proteins
PubMed: 38172607
DOI: 10.1038/s41598-023-50870-2 -
Zhonghua Er Ke Za Zhi = Chinese Journal... Jan 2024To summarize the clinical features and genetic characteristics of Zellweger spectrum disorder caused by PEX6 gene variation. This was a case series research. Clinical... (Review)
Review
To summarize the clinical features and genetic characteristics of Zellweger spectrum disorder caused by PEX6 gene variation. This was a case series research. Clinical date and genetic results of 2 neonatal cases of Zellweger syndrome caused by PEX6 gene variation in Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science & Technology and Affiliated Hospital of Guangdong Medical University from July 2021 to July 2022 were retrospectively collected and analyzed. Literature up to August 2023 was searched from electronic databases of China National Knowledge Infrastructure (CNKI), Wanfang Data and PubMed with the combined keywords of "Zellweger syndrome" "Zellweger spectrum disorder", and "PEX6 gene" both in Chinese and English. The main clinical features and genetic characteristics of Zellweger spectrum disorder caused by PEX6 gene variation were summarized. The 2 male neonates both developed clinical manifestations as dyspnea, hypotonia, feeding difficulties, enlarged fontanelle, and high palatine arch after birth. Biochemical parameters indicated elevated bile acids, and the cranial ultrasound showed the enlarged bilateral ventricles and subependymal cyst in both 2 neonates. Zellweger syndrome was confirmed by whole exome sequencing, and the results revealed PEX6 gene variation in the 2 neonates, including compound heterozygous variants c.315G>A and c.2095-3T>G, and homozygous variant c.506_507del. Case 1 was hospitalized for 5 days, and case 2 for 32 days; they both died shortly after being discharged (the specific time is unknown). Literature review found 26 patients, including 2 neonates in this study, with Zellweger spectrum disorder caused by PEX6 gene defect reported in 1 Chinese article and 11 English articles. Clinical features included hearing loss (19 cases), developmental delay (19 cases), vision impairment (19 cases), elevated very long chain fatty acids (17 cases), brain malformations (15 cases), hypotonia (12 cases), hepatic insufficiency (12 cases), distinctive facies (10 cases), and dental impairment (9 cases). Compound heterozygous variations dominated the variation types (15 cases), and the frameshift variations (16 cases) were the main pathogenic variations. Zellweger spectrum disorder should be considered when neonates show hypotonia, feeding difficulty, distinctive facial appearance, brain malformations and failure of hearing screening, or when older children show retinitis pigmentosa, sensorineural hearing loss, amelogenesis imperfecta and developmental delays. Detection of genetic variation in the PEX gene is crucial for definitive diagnosis.
Topics: Child; Infant, Newborn; Humans; Male; Adolescent; Zellweger Syndrome; Muscle Hypotonia; Retrospective Studies; Frameshift Mutation; Exome Sequencing; Mutation; ATPases Associated with Diverse Cellular Activities
PubMed: 38154976
DOI: 10.3760/cma.j.cn112140-20230914-00191