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Journal of Medical Case Reports Feb 2021Rehabilitation of the entire dentition with amelogenesis imperfecta (AI) tends to pose a great challenge to the clinician. Most of the cases of amelogenesis imperfecta... (Review)
Review
BACKGROUND
Rehabilitation of the entire dentition with amelogenesis imperfecta (AI) tends to pose a great challenge to the clinician. Most of the cases of amelogenesis imperfecta are reported to be associated with skeletal and dental deformities which results in severe sensitivity of the dental tissues.
CASE PRESENTATION
This clinical case report marks out the total restoration of the oral condition of a young Indian patient diagnosed with the hypoplastic type of amelogenesis imperfecta. Fixed metal ceramic prosthesis were planned to strengthen the masticatory activity, aesthetics, to banish the dental sensitivity and to build up the general persona of the patient. The patient was followed-up at 6 months, 1 year and 2 years intervals. Functional and esthetic impairment was not visible after the follow up period and the treatment outcome was successful. The entire treatment plan was intended to enhance the functional, esthetic and the masticatory component of the occlusal architecture.
CONCLUSION
This case report details the presentation, characteristic radiographic findings, and management of a patient with an extremely rare condition of amelogenesis imperfecta.
Topics: Amelogenesis Imperfecta; Esthetics, Dental; Humans; Patient Care Planning; Treatment Outcome
PubMed: 33557885
DOI: 10.1186/s13256-020-02586-4 -
Physiological Reviews Jul 2017Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as... (Review)
Review
Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
Topics: Ameloblasts; Amelogenesis; Animals; Dental Enamel; Dental Enamel Proteins; Evolution, Molecular; Genetic Predisposition to Disease; Humans; Oral Health; Phenotype; Species Specificity; Tooth Abnormalities; Tooth Diseases
PubMed: 28468833
DOI: 10.1152/physrev.00030.2016 -
PloS One 2021Molar incisor hypomineralization (MIH) is an enamel condition characterized by lesions ranging in color from white to brown which present rapid caries progression, and... (Clinical Trial)
Clinical Trial
Molar incisor hypomineralization (MIH) is an enamel condition characterized by lesions ranging in color from white to brown which present rapid caries progression, and mainly affects permanent first molars and incisors. These enamel defects usually occur when there are disturbances during the mineralization or maturation stage of amelogenesis. Both genetic and environmental factors have been suggested to play roles in MIH's development, but no conclusive risk factors have shown the source of the disease. During head and neck development, the interferon regulatory factor 6 (IRF6) gene is involved in the structure formation of the oral and maxillofacial regions, and the transforming growth factor alpha (TGFA) is an essential cell regulator, acting during proliferation, differentiation, migration and apoptosis. In this present study, it was hypothesized that these genes interact and contribute to predisposition of MIH. Environmental factors affecting children that were 3 years of age or older were also hypothesized to play a role in the disease etiology. Those factors included respiratory issues, malnutrition, food intolerance, infection of any sort and medication intake. A total of 1,065 salivary samples from four different cohorts were obtained, and DNA was extracted from each sample and genotyped for nine different single nucleotide polymorphisms. Association tests and logistic regression implemented in PLINK were used for analyses. A potential interaction between TGFA rs930655 with all markers tested in the cohort from Turkey was identified. These interactions were not identified in the remaining cohorts. Associations (p<0.05) between the use of medication after three years of age and MIH were also found, suggesting that conditions acquired at the age children start to socialize might contribute to the development of MIH.
Topics: Adolescent; Amelogenesis; Child; Dental Enamel Hypoplasia; Female; Gene-Environment Interaction; Genotype; Humans; Incisor; Male; Molar; Polymorphism, Single Nucleotide; Transforming Growth Factor alpha
PubMed: 33406080
DOI: 10.1371/journal.pone.0241898 -
Orphanet Journal of Rare Diseases Apr 2007Amelogenesis imperfecta (AI) represents a group of developmental conditions, genomic in origin, which affect the structure and clinical appearance of enamel of all or... (Review)
Review
Amelogenesis imperfecta (AI) represents a group of developmental conditions, genomic in origin, which affect the structure and clinical appearance of enamel of all or nearly all the teeth in a more or less equal manner, and which may be associated with morphologic or biochemical changes elsewhere in the body. The prevalence varies from 1:700 to 1:14,000, according to the populations studied. The enamel may be hypoplastic, hypomineralised or both and teeth affected may be discoloured, sensitive or prone to disintegration. AI exists in isolation or associated with other abnormalities in syndromes. It may show autosomal dominant, autosomal recessive, sex-linked and sporadic inheritance patterns. In families with an X-linked form it has been shown that the disorder may result from mutations in the amelogenin gene, AMELX. The enamelin gene, ENAM, is implicated in the pathogenesis of the dominant forms of AI. Autosomal recessive AI has been reported in families with known consanguinity. Diagnosis is based on the family history, pedigree plotting and meticulous clinical observation. Genetic diagnosis is presently only a research tool. The condition presents problems of socialisation, function and discomfort but may be managed by early vigorous intervention, both preventively and restoratively, with treatment continued throughout childhood and into adult life. In infancy, the primary dentition may be protected by the use of preformed metal crowns on posterior teeth. The longer-term care involves either crowns or, more frequently these days, adhesive, plastic restorations.
Topics: Adolescent; Adult; Amelogenesis Imperfecta; Amelogenin; Child; Child, Preschool; Dental Enamel; Dental Enamel Proteins; Diagnosis, Differential; Genetic Diseases, X-Linked; Humans; Infant; Kallikreins; Matrix Metalloproteinase 20; Mutation; Syndrome
PubMed: 17408482
DOI: 10.1186/1750-1172-2-17 -
International Journal of Environmental... Jul 2021Amelogenesis imperfecta (AI) is defined as an interruption of enamel formation due to genetic inheritance. To prevent malfunction of the masticatory system and an...
Amelogenesis imperfecta (AI) is defined as an interruption of enamel formation due to genetic inheritance. To prevent malfunction of the masticatory system and an unaesthetic appearance, various treatment options are described. While restoration with a compomer in the anterior region and stainless steel crowns in the posterior region is recommended for deciduous dentition, the challenges when treating such structural defects in mixed or permanent dentition are changing teeth and growing jaw, allowing only temporary restoration. The purpose of this case report is to demonstrate oral rehabilitation from mixed to permanent dentition. The dentition of a 7-year-old patient with AI type I and a 12-year-old patient with AI type II was restored under general anesthesia to improve their poor aesthetics and increase vertical dimension, which are related to problems with self-confidence and reduced oral health quality of life. These two cases show the complexity of dental care for structural anomalies of genetic origin and the challenges in rehabilitating the different phases of dentition.
Topics: Amelogenesis Imperfecta; Child; Crowns; Dentition, Permanent; Humans; Quality of Life; Self Concept
PubMed: 34281141
DOI: 10.3390/ijerph18137204 -
Swiss Dental Journal Dec 2022
Topics: Humans; Amelogenesis Imperfecta
PubMed: 36448981
DOI: No ID Found -
Frontiers in Bioscience (Landmark... Jun 2012Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable... (Review)
Review
Enamel is a hard nanocomposite bioceramic with significant resilience that protects the mammalian tooth from external physical and chemical damages. The remarkable mechanical properties of enamel are associated with its hierarchical structural organization and its thorough connection with underlying dentin. This dynamic mineralizing system offers scientists a wealth of information that allows the study of basic principels of organic matrix-mediated biomineralization and can potentially be utilized in the fields of material science and engineering for development and design of biomimetic materials. This chapter will provide a brief overview of enamel hierarchical structure and properties and the process and stages of amelogenesis. Particular emphasis is given to current knowledge of extracellular matrix protein and proteinases, and the structural chemistry of the matrix components and their putative functions. The chapter will conclude by discussing the potential of enamel for regrowth.
Topics: Amelogenesis Imperfecta; Amelogenin; Animals; Biomimetic Materials; Dental Enamel; Dental Enamel Proteins; Dental Materials; Extracellular Matrix Proteins; Humans; Hydrogen-Ion Concentration; Minerals; Peptide Hydrolases; Protein Multimerization; Tooth Calcification
PubMed: 22652761
DOI: 10.2741/4034 -
Journal of Dental Research Jun 2015Enamel is unique. It is the only epithelial-derived mineralized tissue in mammals and has a distinct micro- and nanostructure with nanofibrous apatite crystals as... (Review)
Review
Enamel is unique. It is the only epithelial-derived mineralized tissue in mammals and has a distinct micro- and nanostructure with nanofibrous apatite crystals as building blocks. It is synthesized by a highly specialized cell, the ameloblast, which secretes matrix proteins with little homology to any other known amino acid sequence, but which is composed of a primary structure that makes it competent to self-assemble and control apatite crystal growth at the nanometer scale. The end-product of ameloblast activity is a marvel of structural engineering: a material optimized to provide the tooth with maximum biting force, withstanding millions of cycles of loads without catastrophic failure, while also protecting the dental pulp from bacterial attack. This review attempts to bring into context the mechanical behavior of enamel with the developmental process of amelogenesis and structural development, since they are linked to tissue function, and the importance of controlling calcium phosphate mineralization at the nanometer scale. The origins of apatite nanofibers, the development of a stiffness gradient, and the biological processes responsible for the synthesis of a hard and fracture-resistant dental tissue are discussed with reference to the evolution of enamel from a fibrous composite to a complex, tough, and damage-tolerant coating on dentin.
Topics: Ameloblasts; Amelogenesis; Apatites; Biomechanical Phenomena; Calcium Phosphates; Crystallization; Dental Enamel; Dental Enamel Proteins; Humans; Nanofibers; Tooth Calcification
PubMed: 25800708
DOI: 10.1177/0022034515577963 -
Frontiers in Physiology 2017Amelogenesis imperfecta (AI) is the name given to a heterogeneous group of conditions characterized by inherited developmental enamel defects. AI enamel is abnormally... (Review)
Review
Amelogenesis imperfecta (AI) is the name given to a heterogeneous group of conditions characterized by inherited developmental enamel defects. AI enamel is abnormally thin, soft, fragile, pitted and/or badly discolored, with poor function and aesthetics, causing patients problems such as early tooth loss, severe embarrassment, eating difficulties, and pain. It was first described separately from diseases of dentine nearly 80 years ago, but the underlying genetic and mechanistic basis of the condition is only now coming to light. Mutations in the gene , encoding an extracellular matrix protein secreted by ameloblasts during enamel formation, were first identified as a cause of AI in 1991. Since then, mutations in at least eighteen genes have been shown to cause AI presenting in isolation of other health problems, with many more implicated in syndromic AI. Some of the encoded proteins have well documented roles in amelogenesis, acting as enamel matrix proteins or the proteases that degrade them, cell adhesion molecules or regulators of calcium homeostasis. However, for others, function is less clear and further research is needed to understand the pathways and processes essential for the development of healthy enamel. Here, we review the genes and mutations underlying AI presenting in isolation of other health problems, the proteins they encode and knowledge of their roles in amelogenesis, combining evidence from human phenotypes, inheritance patterns, mouse models, and studies. An LOVD resource (http://dna2.leeds.ac.uk/LOVD/) containing all published gene mutations for AI presenting in isolation of other health problems is described. We use this resource to identify trends in the genes and mutations reported to cause AI in the 270 families for which molecular diagnoses have been reported by 23rd May 2017. Finally we discuss the potential value of the translation of AI genetics to clinical care with improved patient pathways and speculate on the possibility of novel treatments and prevention strategies for AI.
PubMed: 28694781
DOI: 10.3389/fphys.2017.00435 -
Frontiers in Physiology 2017During the secretory phase of their life-cycle, ameloblasts are highly specialized secretory cells whose role is to elaborate an extracellular matrix that ultimately... (Review)
Review
During the secretory phase of their life-cycle, ameloblasts are highly specialized secretory cells whose role is to elaborate an extracellular matrix that ultimately confers both form and function to dental enamel, the most highly mineralized of all mammalian tissues. In common with many other "professional" secretory cells, ameloblasts employ the unfolded protein response (UPR) to help them cope with the large secretory cargo of extracellular matrix proteins transiting their ER (endoplasmic reticulum)/Golgi complex and so minimize ER stress. However, the UPR is a double-edged sword, and, in cases where ER stress is severe and prolonged, the UPR switches from pro-survival to pro-apoptotic mode. The purpose of this review is to consider the role of the ameloblast UPR in the biology and pathology of amelogenesis; specifically in respect of amelogenesis imperfecta (AI) and fluorosis. Some forms of AI appear to correspond to classic proteopathies, where pathological intra-cellular accumulations of protein tip the UPR toward apoptosis. Fluorosis also involves the UPR and, while not of itself a classic proteopathic disease, shares some common elements through the involvement of the UPR. The possibility of therapeutic intervention by pharmacological modulation of the UPR in AI and fluorosis is also discussed.
PubMed: 28951722
DOI: 10.3389/fphys.2017.00653