|Year : 2012 | Volume
| Issue : 4 | Page : 283-285
Department of Oral Medicine and Radiology, JSS Dental College, Constituent College of JSS University, Mysore, Karnataka, India
|Date of Web Publication||27-Feb-2013|
K P Mahesh
Department of Oral Medicine and Radiology, JSS Dental College, Constituent College of JSS University, Mysore, Karnataka
Source of Support: None, Conflict of Interest: None
Amelogenesis imperfecta (AI) represents a group of developmental disorder of teeth structure, genomic in origin, which affects the structure and clinical appearance of enamel of all or nearly all the teeth, and which may be associated with morphologic or biochemical changes elsewhere in the body. It can be hypoplastic, hypomineralized, or both. Teeth affected may be discoloured, sensitive, or prone to disintegration. A case of yellow brown discoloration in a hindu female aged 26, reported with same chief complaint. On examination of the patient, generalized yellowish brown discoloration of the teeth was seen. Radiographic and histopathologic examination confirms the diagnosis of AI.
Keywords: Amelo, amelex, hypoplastic, amelogenesis, enamel hypoplasia
|How to cite this article:|
Mahesh K P. Amelogenesis imperfecta. Int J Health Allied Sci 2012;1:283-5
| Introduction|| |
Amelogenesis imperfecta (AI) (congenital enamel hypoplasia) presents with abnormal formation of the enamel or external layer of teeth.  The prevalence varies from 1:700 to 1:14,000, according to the populations studied.  The enamel may be hypoplastic, hypomineralized, or both and teeth affected may be discoloured, sensitive, or prone to disintegration.
AI is a tooth development disorder in which the teeth are covered with thin, abnormally formed enamel. People afflicted with AI have teeth with abnormal colour: yellow, brown, or grey. The teeth have a higher risk for dental caries and are hypersensitive to temperature changes. AI is passed down through families as a dominant trait. The enamel of the tooth is soft and thin. The teeth appear yellow and are easily damaged as they are fragile. Both deciduous and permanent teeth are affected.
About 5% of cases are caused by mutations in the AMELX gene and are inherited in an X-linked pattern. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In most cases, males with X-linked AI experience more severe dental abnormalities than females with this form of condition. 
Researchers have described at least 14 forms of amelogenesis imperfect. These types are distinguished by their specific dental abnormalities and by their pattern of inheritance. , This report of A I gives an insight of clinical, radiographical, and histopathology (ground section).
| Case Report|| |
A female patient aged 26 years reported to our department with complaint of discoloration of the teeth. Discoloration of teeth is seen since childhood [Figure 1] and [Figure 2] and tooth surface was slightly rough in nature no pitting was seen. A provisional diagnosis of amelogenesis imperfect was given. Radiographs were taken and panoramic radiographs showed generalized thinning of enamel layer and irregular surface of enamel [Figure 3], similar features were seen on IOPAR in 36 regions which was taken to rule out periapical pathology.
|Figure 3: OPG reveals a thin layer of enamel with all other features normal|
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Histopathology (ground section) [Figure 4] revealed thin enamel with regular dentinal surface. No other abnormalities were seen.
|Figure 4: Ground section revealing a thin layer of enamel and a normal dentinal layer|
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Based on the clinical, radiographical, and histopathological investigations final diagnosis was given as AI.
| Discussion|| |
AI represents a group of conditions, genomic in origin, which affect the structure and clinical appearance of enamel, 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.  AI is a developmental condition of the dental enamel (characterized by hypoplasia and/or hypomineralization) that shows autosomal dominant, autosomal recessive, sex-linked, and sporadic inheritance patterns, as well as sporadic cases. AI can have different inheritance patterns depending on the gene that is altered. Most cases are caused by mutations in the ENAM gene and are inherited in an autosomal dominant pattern. This type of inheritance means one copy of the altered gene in each cell is sufficient to cause the disorder. AI is also inherited in an autosomal recessive pattern; this form of the disorder can result from mutations in the ENAM or MMP20 gene. Autosomal recessive inheritance means two copies of the gene in each cell are altered. AI is due to the malfunction of the proteins in the enamel: ameloblastin, enamelin, tuftelin, and amelogenin.
The family history, pedigree plotting, clinical observation, and meticulous recording form the backbone of diagnosis, as the case in any potentially inherited condition.
Intra-oral radiographs will reveal the relative contrast between enamel and dentine in cases where mineralization may have been affected. 
Laboratory genetic diagnosis is presently only a research tool.
Extrinsic disorders of tooth formation, chronological disorders of tooth formation, and localized disorders of tooth formation should be considered in the differential diagnosis.
The most common differential diagnosis is dental fluorosis. The variability of this condition, from mild white "flecking" of the enamel to profoundly dense white colouration with random, disfiguring areas of staining and hypoplasia, requires careful questioning to distinguish from AI.
Fluorosis may present with areas of horizontal white banding corresponding to periods of more intense fluoride intake and may show the premolars or second permanent molars to be spared.
In the latter case, the history will often reveal excessive fluoride intake either in terms of a habit such as eating toothpaste in childhood, or related to a local water supply.
A similar distribution of findings-chronological enamel hypoplasia-can arise from one of many causes during the time of tooth formation. Ranging from gastrointestinal upset of a prolonged nature, such as coeliac disease (a diagnosis which may not be confirmed until later life), to anti-leukemic therapy; these causes may be identified from the history and from the chronological distribution of the markings seen.  Molar-Incisor Hypomineralization (MIH), which shows features quite unlike these findings, has been considered.
Studies have shown histopathologically thin enamel and prismatic structure with no coronal cementum. Similarly microscopic studies also show variety of enamel defects including hypomineralization, non-prismatic enamel, and irregular surface globules.
| Conclusion|| |
In vast variety of developmental disorders of the teeth coming to a diagnosis is an uphill task, so history, clinical, radiographic, and histopathology play a vital role. Early diagnosis and treatment is a must in such cases to avoid the social stigma.
| Acknowledgement|| |
Author thank the patient for providing consent to use clinical photographs.
| References|| |
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]