Some patients with generalized attrition and teeth discoloration may want their anterior teeth to be treated just for esthetic improvement. Ameologenesis imperfecta, however, should be considered for such patients prior to any treatment with thorough clinical and radiographic examination. If a patient is diagnosed with amelogenesis imperfecta, the treatment on anterior teeth just for esthetic purpose is not advisable. In this case, a young man with amelogenesis imperfecta was treated with metal-ceramic restorations. The patient had generalized attrition, teeth discoloration, crown fracture, and cross-bite on the left teeth. The ultimate objective of this treatment was to enhance esthetics and masticatory function. The cross-bite on the left anterior teeth was treated with restorations, whereas the reverse horizontal overlap was maintained on the posterior. The patient was satisfied with the result esthetically and functionally, and the third month recall examination revealed no pathologic changes associated with the treatment.
Amelogenesis ; Amelogenesis Imperfecta ; Crowns ; Esthetics ; Humans ; Tooth ; Young Adult

OBJECTIVETo study the differences between amelogenesis imperfecta (AI) teeth and normal human (NH) teeth in wear properties.

METHODSThe ultrastructure of the human tooth enamel from adult patient diagnosed with AI was investigated using atomic force microscope (AFM) and compared with the surface of normal human tooth enamel. The composition of tooth enamel of AI teeth and normal human teeth were analyzed by energydispersive X-ray spectroscopy (EDX). The properties of micro-friction and wear between AI teeth and normal human teeth were compared using nano-scratch technology and scanning electron microscope (SEM).

RESULTSThe AI teeth were found porosity and the loosely packed hydroxyapatite was distributed randomly compared with normal human teeth. The amount of C was higher while the amount of Ca, P were lower in AI teeth than normal human teeth. The friction coefficient of both AI teeth and normal human teeth was increasing with the load increased and the friction coefficient of AI teeth was higher than normal human teeth with the same load. Meanwhile, the destruction of AI teeth was more severe than normal human teeth with the same load.

CONCLUSIONThe AI teeth has significant differences with normal human teeth on micro-structure, composition and micro-friction and wear properties. Thus, we need to have a general consideration of all these results when doing clinical restorations.

Ameloblasts are responsible for the formation and maintenance of enamel which is an epithelially derived protective covering for teeth. Ameloblast differentiation is controlled by sequential epithelial-mesenchymal interactions. However, little is known about the differentiation and maturation mechanisms. OD314 was firstly identified from odontoblasts by subtraction between odontoblast/pulp cells and osteoblast/dental papilla cells, even though OD314 protein was also expressed in ameloblast during tooth formation. In this study, to better understand the biological function of OD314 during amelogenesis, we examined expression of the OD314 mRNA and protein in various stages of ameloblast differentiation using in-situ hybridization and immunohistochemistry. The results were as follows : 1. The ameloblast showed 4 main morphological and functional stages referred to as the presecretory, secretory, smooth-ended, and ruffle-ended. 2. OD314 mRNA was expressed in secretory ameloblast and increased according to the maturation of the cells. 3. OD314 protein was not expressed in presecretory ameloblast but expressed in secretory ameloblast and maturative ameloblast. OD314 protein was distributed in entire cytoplasm of secretory ameloblast. However, OD314 was localized at the proxiamal and distal portion of the cytoplasm of smooth-ended and ruffle-ended ameloblast. These results suggest that OD314 may play important roles in the ameloblast differentiation and maturation.
Ameloblasts* ; Amelogenesis ; Cytoplasm ; Dental Enamel ; Immunohistochemistry ; Odontoblasts ; RNA, Messenger ; Tooth

OBJECTIVETo localize the gene (s) responsible for autosomal dominant hypocalcified amelogenesis imperfecta in a Chinese family.

METHODSA Chinese family which was diagnosed as autosomal dominant hypocalcified amelogenesis imperfecta (AD) was studied. Venous blood from nineteen family members was collected and genomic DNA was extracted from the blood. Eight short tandem repeats (STRs) spanning five hereditary AI candidate genes were selected and linkage analysis between the genetic markers and the disease loci was performed.

RESULTSGenotype of the eight STRs were acquired, the linkage analysis result can not support that the gene for AI pedigrees was linked to ENAM, AMBN, TUF1, KLK4 or MMP-20.

CONCLUSIONThe results can not support all proposed candidate gene regions as causal for autosomal dominant hypocalcified AI in this family. These linkage findings provide further evidence for genetic heterogeneity among families with autosomal dominant AI and indicate that, at least, some forms of autosomal dominant AI are not caused by a gene in the five most commonly reported AI candidate genes.

Amelogenesis imperfecta (AI) is a hereditary disease that affects enamel formation. The patients with AI have esthetic and functional problems due to damage of multiple teeth. So most AI patients resolve these problem through the conservative and prosthodontic treatments. In our case, It was difficult to obtain good results in means of conservative and prosthodontic treatments, because the AI patient had skeletal Class III malocclusion. Moreover, because of vertical dimension loss due to severe dental caries and maxillofacial skeletal disharmony, the ordinary prosthodontic treatment was troublesome. So we planned orthognathic surgery to resolve these problems. After the endodontic treatment, temporary restoration was delivered for stable post-operative occlusion. Then orthognathic surgery was done, and final restoration was delivered in stable period. We obtained satisfactory results in esthetic and functional aspects through multidisciplinary management(conservative treatment, prosthodontics and orthognathic surgery).]]>
Amelogenesis Imperfecta ; Amelogenesis ; Dental Caries ; Dental Enamel ; Genetic Diseases, Inborn ; Humans ; Malocclusion ; Orthognathic Surgery ; Prosthodontics ; Tooth ; Vertical Dimension

Numerous cases of enamel renal syndrome have been previously reported. Various terms, such as enamel renal syndrome, amelogenesis imperfecta and gingival fibromatosis syndrome, and enamel-renal-gingival syndrome, have been used for patients presenting with the dental phenotype characteristic of this condition, nephrocalcinosis or nephrolithiasis, and gingival findings. This report describes a case of amelogenesis imperfecta of the enamel agenesis variety with nephrolithiasis in a 21-year-old male patient who complained of small teeth. The imaging modalities employed were conventional radiography, cone-beam computed tomography, and renal sonography. Such cases are first encountered by dentists, as other organ or metabolic diseases are generally hidden. Hence, cases of amelogenesis imperfecta should be subjected to advanced diagnostic modalities, incorporating both dental and medical criteria, in order to facilitate comprehensive long-term management.
Amelogenesis Imperfecta* ; Amelogenesis* ; Cone-Beam Computed Tomography ; Dental Enamel Hypoplasia ; Dental Enamel* ; Dentists ; Fibromatosis, Gingival ; Humans ; Kidney Diseases ; Male ; Metabolic Diseases ; Nephrocalcinosis ; Nephrolithiasis* ; Phenotype ; Radiography ; Tooth ; Young Adult

Amelogenesis imperfecta characterized as abnormally formed enamel is caused by a defect of unique group of genes. Patients affected by this disease might have difficulties in social and psychological aspects due to non-esthetic teeth as well as functional problems caused by enamel detachment and tooth wear from their early ages. Adult patients with amelogenesis imperfecta can be treated with full-mouth restorations, which make functional and esthetic rehabilitations of severely worn tooth. However, the anterior open bite and lack of occlusal clearance for posterior teeth restorations due to compensatory extrusion are the intervening factors in the prosthetic treatment. Therefore, the determination of anterior tooth lengths, vertical dimension, and anterior guidance should be set carefully. Recently, computer-aided design and computer-aided manufacturing (CAD/CAM) techniques help systematic approaches and enable dentists to reduce time-consuming procedures in the diagnosis and treatment of full-mouth rehabilitation. This case report demonstrates the successful full mouth rehabilitation using a CAD/CAM system in a young adult patient with amelogenesis imperfecta and anterior open bite.
Adult ; Amelogenesis Imperfecta* ; Amelogenesis* ; Computer-Aided Design ; Dental Enamel ; Dentists ; Diagnosis ; Humans ; Mouth Rehabilitation ; Open Bite* ; Rehabilitation* ; Tooth ; Tooth Wear ; Vertical Dimension ; Young Adult

The purpose of this study was to investigate the radiation effect on the stages of amelogenesis. Twenty 11-day-old rats which were irradiated by 4GY of gamma radiation on the 19th prenatal day were used for the experimental group and twenty 11-day-old rats which were not irradiated were used for the control group. The length of each zone of amelogenesi s were measured on the sagittal section using a light microscopic enlargement at 400 X the normal view while the morphol ogic changes of ameloblasts of each zone were observed electron-microscopically. The obtined results were as followed: 1. The length of the region of facing pulp and facing dentin of the zone of presecretion were increased by 11.5%(P<0.05) and 17.7%(P<0.01), respectively. 2. The length of the zone of secretion was increased by 17.3%(P<0.01), but the zone of maturation was decreased by 15.3%(P<0.01). 3. The total length of the zone of amelogenesis was not changed significantly(P>0.05). 4. Electron-microscopically, enlargement of the cell membrane, rER, mitochondria, and nuclear membrane were observed. These changes were mostly severe in the zone of maturation.
Ameloblasts ; Amelogenesis* ; Animals ; Cell Membrane ; Dentin ; Gamma Rays ; Incisor* ; Mitochondria ; Nuclear Envelope ; Radiation Effects* ; Rats*

The purpose of this study was to investigate the radiation effect on the stages of amelogenesis. Twenty 11-day-old rats which were irradiated by 4GY of gamma radiation on the 19th prenatal day were used for the experimental group and twenty 11-day-old rats which were not irradiated were used for the control group. The length of each zone of amelogenesi s were measured on the sagittal section using a light microscopic enlargement at 400 X the normal view while the morphol ogic changes of ameloblasts of each zone were observed electron-microscopically. The obtined results were as followed: 1. The length of the region of facing pulp and facing dentin of the zone of presecretion were increased by 11.5%(P<0.05) and 17.7%(P<0.01), respectively. 2. The length of the zone of secretion was increased by 17.3%(P<0.01), but the zone of maturation was decreased by 15.3%(P<0.01). 3. The total length of the zone of amelogenesis was not changed significantly(P>0.05). 4. Electron-microscopically, enlargement of the cell membrane, rER, mitochondria, and nuclear membrane were observed. These changes were mostly severe in the zone of maturation.
Ameloblasts ; Amelogenesis* ; Animals ; Cell Membrane ; Dentin ; Gamma Rays ; Incisor* ; Mitochondria ; Nuclear Envelope ; Radiation Effects* ; Rats*

Ameloblasts are specialized cells derived from the dental epithelium that produce enamel, a hierarchically structured tissue comprised of highly elongated hydroxylapatite (OHAp) crystallites. The unique function of the epithelial cells synthesizing crystallites and assembling them in a mechanically robust structure is not fully elucidated yet, partly due to limitations with in vitro experimental models. Herein, we demonstrate the ability to generate mineralizing dental epithelial organoids (DEOs) from adult dental epithelial stem cells (aDESCs) isolated from mouse incisor tissues. DEOs expressed ameloblast markers, could be maintained for more than five months (11 passages) in vitro in media containing modulators of Wnt, Egf, Bmp, Fgf and Notch signaling pathways, and were amenable to cryostorage. When transplanted underneath murine kidney capsules, organoids produced OHAp crystallites similar in composition, size, and shape to mineralized dental tissues, including some enamel-like elongated crystals. DEOs are thus a powerful in vitro model to study mineralization process by dental epithelium, which can pave the way to understanding amelogenesis and developing regenerative therapy of enamel.
Mice ; Animals ; Durapatite/metabolism* ; Dental Enamel/metabolism* ; Ameloblasts/metabolism* ; Amelogenesis ; Stem Cells ; Organoids