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1.
Cells Tissues Organs ; 191(4): 301-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19923784

RESUMO

In a group of families in northern Sweden, a mutation in the ENAM gene (predicted to produce a highly truncated protein) results in the local hypoplastic form of autosomal dominant amelogenesis imperfecta. In this study, sections of deciduous teeth from members of 3 of these families were examined by scanning electron microscopy (SEM) and the enamel mineral was analysed by energy dispersive X-ray spectroscopy (EDX). The sections were also probed with antibodies raised to a conserved sequence of the enamelin protein. Selected intact teeth were first analysed by digital imaging and ascribed with an 'Enamel Defects Index' (EDI) score. SEM of tooth sections revealed disrupted prism morphology and the prisms had a glass-like appearance in some areas. These areas of dysplasia were sometimes irregular but formed regular arrays in others. Comparison of EDI scores with SEM indicated that in one tooth the surface had no measurable defects but significant defects were present in the underlying enamel microstructure. SEM immunohistochemistry with the antibody raised to a fragment of the enamelin protein produced positive, but light, labelling throughout normal enamel. In dysplastic areas, however, the labelling intensity appeared to be reduced. The results indicate that the presence of functional enamelin in the correct amounts is necessary for correct prism morphogenesis. In addition, a combination of EDI and structural analysis indicate that defects in enamel microstructure are not necessarily visible as defects on the surface of the tooth, suggesting the possibility, at least, that some instances of under-diagnosis may occur.


Assuntos
Amelogênese Imperfeita/genética , Hipoplasia do Esmalte Dentário/genética , Proteínas do Esmalte Dentário/genética , Esmalte Dentário/ultraestrutura , Mutação , Proteínas/genética , Dente Decíduo/ultraestrutura , Amelogênese Imperfeita/patologia , Sequência de Aminoácidos , Hipoplasia do Esmalte Dentário/patologia , Proteínas da Matriz Extracelular , Humanos , Microscopia Eletrônica de Varredura , Dados de Sequência Molecular , Linhagem , Proteínas/metabolismo
2.
Arch Oral Biol ; 54 Suppl 1: S86-92, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18768169

RESUMO

AIMS: To enhance the phenotypic description and quantification of enamel defects from a North Sweden sample of extracted and exfoliated teeth originating from families with Amelogenesis Imperfecta by use of the extended enamel defects index (EDI) and image analysis to demonstrate the comparable reliability and value of the additional measurements. METHODS AND RESULTS: The sample comprised 109 deciduous and 7 permanent teeth from 32 individuals of 19 families with Amelogenesis Imperfecta in Northern Sweden. A special holder for individual teeth was designed and the whole sample was examined using the extended EDI and an image analysis system. In addition to the extended EDI definitions, the calibrated images were measured for tooth surface area, defect area and percentage of surface affected using image analysis techniques. The extended EDI was assessed using weighted and unweighted Kappa statistics. The reliability of imaging and measurement was determined using Fleiss' intra-class correlation coefficient (ICCC). Kappa values indicated good or excellent intra-operator repeatability and inter-operator reproducibility for the extended EDI. The Fleiss ICCC values indicated excellent repeatability for the image analysis measurements. Hypoplastic pits on the occlusal surfaces were the most frequent defect in this sample (82.6%). The occlusal surface displayed the most post-eruptive breakdown (39.13%) whilst the incisal portion of the buccal surfaces showed most diffuse opacities (53.4%). Image analysis methods demonstrated the largest mean hypoplastic pit areas were on the lingual surfaces. The largest mean post-eruptive breakdown areas were on the lingual surfaces of posterior teeth. The largest mean demarcated opacity areas were found on the labial surfaces. CONCLUSIONS: The extended EDI and the standardised image acquisition and analysis system provided additional information to conventional measurement techniques. Additional phenotypic variables were described.


Assuntos
Amelogênese Imperfeita/patologia , Esmalte Dentário/anormalidades , Processamento de Imagem Assistida por Computador , Feminino , Humanos , Modelos Logísticos , Masculino , Fenótipo , Reprodutibilidade dos Testes , Suécia , Esfoliação de Dente , Extração Dentária
3.
Caries Res ; 41(1): 26-33, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17167256

RESUMO

Preventive measures have dramatically decreased the prevalence of dental caries in children. However, risk factors for the disease in children living in low-prevalence areas remain elusive. In the present study we evaluated associations between dental caries, saliva levels of mutans streptococci and lactobacilli, and diet with special emphasis on the intake of fermentable carbohydrates and dairy products in 4-year-old children living in an area where the overall caries prevalence was low. Dietary intake was recorded in 234 infants as part of the Study of Infant Nutrition in Umeå, Sweden (SINUS). Of these the parents of 124 children gave consent to participate in a follow-up at 4 years of age. Dietary intake, height and weight, dental caries, oral hygiene, including tooth brushing habits, presence of plaque and gingival inflammation, fluoride habits and numbers of mutans streptococci and lactobacilli in saliva were recorded. Using multivariate stepwise logistic regression, caries experience was negatively associated with intake frequency of cheese (OR = 0.67; 95% CI = 0.44-0.98) and positively associated with the salivary level of mutans streptococci (OR = 1.57; 95% CI = 1.21-2.03). Caries experience was not correlated with intake frequency or amounts of carbohydrate-containing foods, with any other particular food, or with daily intake of energy, carbohydrate or any other macro- or micronutrient. We conclude that cheese intake may have a caries-protective effect in childhood populations where the overall caries prevalence and caries experience are low and the children are regularly exposed to fluoride from toothpaste.


Assuntos
Cárie Dentária/epidemiologia , Dieta Cariogênica , Lactobacillaceae/isolamento & purificação , Saliva/microbiologia , Streptococcus mutans/isolamento & purificação , Queijo , Pré-Escolar , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Suécia/epidemiologia
4.
Int J Paediatr Dent ; 15(1): 1-9, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15663439

RESUMO

BACKGROUND: The need for improved oral hygiene routines in individuals with disabilities has been documented in many reports. The aim of this study was to evaluate whether visual pedagogy is a suitable way to teach children with autism how to brush their teeth. METHODS: The investigation took the form of a prospective study including clinical examinations and structured interviews. Based on visual pedagogy, a series of pictures were produced that showed a structured method and technique of tooth brushing. The pictures were placed in the bathroom or wherever tooth brushing was performed. Fourteen children with autism aged between 5 and 13 years (mean age = 9.3 years), and their parents participated. RESULTS: Before the study, all parents found it difficult/very difficult to maintain good oral hygiene in their child. All children had visible plaque on their maxillary incisors and canines. After 12 months, the amount of visible plaque was reduced. After 18 months, most parents found maintaining good oral hygiene easier than before the study. All but one child/parent adopted the programme. CONCLUSIONS: Visual pedagogy is a useful tool in helping people with autism to improve their oral hygiene.


Assuntos
Transtorno Autístico , Assistência Odontológica para a Pessoa com Deficiência/métodos , Higiene Bucal/educação , Adolescente , Criança , Pré-Escolar , Placa Dentária/prevenção & controle , Humanos , Masculino , Cooperação do Paciente , Fotografia Dentária , Inquéritos e Questionários , Ensino/métodos , Escovação Dentária
5.
Int J Paediatr Dent ; 13(5): 327-35, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12924988

RESUMO

OBJECTIVES: The aim of this study was to describe oral development and morphology in 18-month-old children with Down syndrome (DS) treated with palatal plates in combination with structured communication and speech training. The aim is further to describe the design of the palatal plates, compliance in their use and to give a brief report of their effect on oral motor function and speech. SAMPLE AND METHODS: Forty-two children with DS were followed from < or = 6 months of age until 18+/-3 months old. In addition to language intervention, and oral motor and sensory stimulation provided by speech therapists for all children with DS in Sweden, palatal plates provided by dentists are included in the training programme. In the evaluation, the children in the project were compared with two control groups of children matched for age; one group of children with DS who had not been treated with palatal plates, and one group of children with normal development. RESULTS: Compared to the children with normal development, both groups of children with DS had fewer teeth erupted and a lower prevalence of sucking habits. Deviant morphology of the tongue in the form of diastase, lingua plicata or a sulcus in the anterior third of the tongue was only seen in children with DS. All children with normal development had positive values for overjet compared to 53% of the children with DS. The palatal plates were used 2-3 times daily for a total mean time of 15 min. Compliance in use of the plates decreased with age, mainly due to eruption of teeth and subsequent loss of retention. Evaluation of oral motor function and speech show that the children with DS in the project had better motor prerequisites for articulation than the control children with DS. CONCLUSION: Palatal plate therapy did not affect oral parameters, i.e., eruption of teeth, types and prevalence of sucking habits, tongue morphology and symptoms of hypotonia. In combination with oral motor and sensory stimulation, palatal plate therapy had a positive effect on oral motor performance and prerequisites for articulation.


Assuntos
Síndrome de Down/fisiopatologia , Boca/crescimento & desenvolvimento , Terapia Miofuncional/instrumentação , Aparelhos Ortodônticos Funcionais , Estudos de Casos e Controles , Linguagem Infantil , Oclusão Dentária , Feminino , Seguimentos , Humanos , Lactente , Masculino , Boca/patologia , Boca/fisiopatologia , Desenho de Aparelho Ortodôntico , Cooperação do Paciente , Propriocepção/fisiologia , Sensação/fisiologia , Fala/fisiologia , Fonoterapia , Comportamento de Sucção/fisiologia , Língua/anormalidades , Língua/fisiopatologia , Erupção Dentária/fisiologia
6.
Connect Tissue Res ; 43(2-3): 466-71, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12489199

RESUMO

Hypomaturation amelogenesis imperfecta (AI) is characterized clinically by enamel of normal thickness that is hypomineralized, mottled, and detaches easily from the underlying dentin. Autosomal dominant, autosomal recessive, X-linked, and sporadic modes of inheritance have been documented. The present study investigated the elemental composition of the enamel of teeth from individuals demonstrating clinical hypomaturation AI from families representing three of these patterns of inheritance. The aim of the study was to determine if there was any commonality in microscopic phenotype of this defect between families demonstrating the various inheritance patterns. One section from each tooth was microradiographed and then viewed in a scanning electron microscope (SEM) equipped with an ultrathin window energy-dispersive x-ray spectroscopy (EDX) detector. In the SEM, prisms and constituent crystals in discrete areas appeared to be largely obscured by an amorphous material. EDX analysis showed enamel outside these areas to have a composition indistinguishable from control teeth. However, within these affected areas there was a large increase in carbon content (up to a fivefold increase). In some teeth there was also a detectable but smaller increase in the relative amounts of nitrogen or oxygen. The results suggest the defect in these teeth with a common clinical phenotype, irrespective of the pattern of inheritance, demonstrates a commonality in microscopic phenotype. The large increase in carbon content, not matched by an equivalent increase in nitrogen or oxygen, suggests a possible increased lipid content. In those teeth with elevated nitrogen levels there may also be retained protein.


Assuntos
Amelogênese Imperfeita/genética , Amelogênese Imperfeita/metabolismo , Esmalte Dentário/química , Amelogênese Imperfeita/diagnóstico por imagem , Amelogênese Imperfeita/patologia , Carbono/análise , Esmalte Dentário/diagnóstico por imagem , Esmalte Dentário/patologia , Humanos , Microscopia Eletrônica de Varredura , Nitrogênio/análise , Fenótipo , Radiografia , Valores de Referência
7.
Eur J Oral Sci ; 109(1): 8-13, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11330937

RESUMO

A gene encoding the enamel protein ameloblastin (AMBN) was recently localized to a region on chromosome 4q21 containing a gene for the inherited enamel defect local hypoplastic amelogenesis imperfecta (AIH2). Ameloblastin protein is located at the Tomes processes of secretory ameloblasts and in the sheath space between rod-interrod enamel, and the AMBN gene therefore represents a viable candidate gene for local hypoplastic amelogenesis imperfecta (AI). In this study, the genomic organization of human AMBN was characterized. The gene was shown to consist of 13 exons and 12 introns. An alternatively spliced 45 bp sequence was shown not to represent a separate exon and is most likely spliced by the use of a cryptic splice site. The finding that there were no recombinations between an intragenic microsatellite and AIH2 encouraged us to evaluate this gene's potential role as a candidate gene for local hypoplastic AI. Mutation screening was performed on all 13 exons in 20 families and 8 sporadic cases with 6 different forms of AI. DNA variants were found but none that was associated exclusively with local hypoplastic AI or any of the other variants of AI in the identified Swedish families. This study excludes the coding regions and the splice sites of AMBN from a causative role in the pathogenesis of AIH2.


Assuntos
Amelogênese Imperfeita/genética , Proteínas do Esmalte Dentário/genética , Cromossomos Humanos Par 4 , Análise Mutacional de DNA , Éxons , Humanos , Íntrons , Repetições de Microssatélites , Polimorfismo Conformacional de Fita Simples
8.
Int J Paediatr Dent ; 11(1): 11-7, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11309867

RESUMO

OBJECTIVES: To establish the prevalence of numerical and morphological variations of permanent teeth in Swedish 7-year-olds and to accept or reject the hypothesis of a higher prevalence for these conditions in northern Sweden compared to other areas. DESIGN: Cross-sectional. SETTING: Department of Odontology/Pedodontics, Umeå University, Sweden. SAMPLE AND METHODS: A total of 739 healthy Caucasian 7-year-olds residing in the city of Umeå, northern Sweden in 1976. The children were examined clinically and radiographically. RESULTS: The prevalence of hypodontia (excluding third molars) in girls was 8.4%, in boys 6.5%, and in both sexes combined 7.4%. Of the children with hypodontia, the majority (90.9%) lacked one or two teeth. Lower second premolars were the teeth most frequently missing. The prevalence of hyperdontia was 1.9%; 11 girls and three boys were affected; 78% of the supernumerary teeth were mesiodenses. Of the morphological variations, peg-shaped upper lateral incisors were found in 0.8% of the children, double-formation (gemination) in 0.3%, taurodontism in 0.3% and dens invaginatus in 6.8%. One diagnosis was found in 18% of the children, and in almost 8% of them more than one diagnosis was found. CONCLUSIONS: The results agree with those obtained in similar populations and are considered representative of this ethnic group. The hypothesis of a genetically determined higher prevalence of numerical and morphological variations in the study population was not verified.


Assuntos
Anormalidades Dentárias/epidemiologia , Anodontia/epidemiologia , Criança , Estudos Transversais , Dens in Dente/epidemiologia , Feminino , Dentes Fusionados/epidemiologia , Humanos , Masculino , Prevalência , Suécia/epidemiologia , Anormalidades Dentárias/patologia , Dente Supranumerário/epidemiologia
9.
Swed Dent J ; 25(3): 97-104, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11813451

RESUMO

Midazolam is a short-acting benzodiazepine with rapid onset, short duration of action and minimal side effects. The aim of this study was to evaluate the oral administration of midazolam as pre-operative sedation in the dental treatment of uncooperative pediatric patients. Included in the study were 160 children with a mean age of 6.7 +/- 2.6 years (1-14 years), 83 boys and 77 girls. All the patients had been referred for specialist treatment due to behavioral management problems. Treatment was performed in 250 sessions. All the children received an oral dose of 0.2 mg/kg body weight of midazolam. Acceptance of treatment was evaluated according to Rud & Kisling. Local anesthesia followed by restorative treatment and/or extractions constituted more than 90% of the performed treatments. Of the 250 sessions, 63% were performed with total acceptance and 30% with doubtful acceptance. In 7%, no treatment could be performed. No serious complications were registered during or after treatment. All the children were able to leave the clinic one hour after treatment. In conclusion, we consider oral administration of midazolam a safe form of premedication. The route of administration, the short waiting-time and half-life, in combination with a level of sedation that allows treatment to be performed, are the principal advantages of conscious sedation with orally administered midazolam.


Assuntos
Anestesia Dentária/métodos , Ansiolíticos/administração & dosagem , Sedação Consciente/métodos , Hipnóticos e Sedativos/administração & dosagem , Midazolam/administração & dosagem , Administração Oral , Adolescente , Comportamento do Adolescente/efeitos dos fármacos , Anestesia Local , Ansiolíticos/farmacocinética , Criança , Comportamento Infantil/efeitos dos fármacos , Pré-Escolar , Comportamento Cooperativo , Ansiedade ao Tratamento Odontológico/prevenção & controle , Restauração Dentária Permanente , Relações Dentista-Paciente , Emoções/efeitos dos fármacos , Feminino , Meia-Vida , Humanos , Hipnóticos e Sedativos/farmacocinética , Lactente , Masculino , Midazolam/farmacocinética , Fatores de Tempo , Extração Dentária , Resultado do Tratamento
10.
ASDC J Dent Child ; 66(4): 278-9, 229, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10529872

RESUMO

A case of ritual mutilation in a fourteen-year-old Ethiopian girl is described. When the girl was three years old she had frequent stomach problems. According to tribal tradition her illness was thought to arise from her mandibular primary canines and these teeth were removed by a medicine man. The extraction damaged the tooth germs of the succedaneous teeth and resulted in deformed permanent canines. This is the first report of a case of dental mutilation from Ethiopia.


Assuntos
Cultura , Dente Canino/lesões , Medicina Tradicional , Traumatismos Dentários/etnologia , Adolescente , Dente Canino/diagnóstico por imagem , Etiópia/etnologia , Feminino , Humanos , Mandíbula , Radiografia , Suécia , Traumatismos Dentários/diagnóstico por imagem
11.
ASDC J Dent Child ; 66(5): 325-31, 294, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10631888

RESUMO

The aim of the present study is to present and evaluate a model based on visual pedagogy for the introduction of dentistry to preschool children with autism. The model is based on the knowledge that it is easier for these children to communicate via pictures than via words. A book has been produced with distinct color-prints describing every step when visiting the dentist. The project has been designed in cooperation with the multi-professional team involved with the children. A total of sixteen children with autism participated in the project. Evaluation was done after 1.5 years. The ability of the children to cooperate is compared with that of sixteen children with autism of the same ages who were not treated with this method. The capacity of the children in the project to cooperate during dental treatment is superior to that of the control-children. Visual pedagogy is a way of introducing dentistry to children with autism.


Assuntos
Transtorno Autístico , Assistência Odontológica para a Pessoa com Deficiência/métodos , Assistência Odontológica para a Pessoa com Deficiência/psicologia , Transtorno Autístico/psicologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pais/psicologia , Aceitação pelo Paciente de Cuidados de Saúde , Fotografação
12.
ASDC J Dent Child ; 66(6): 419-20, 367, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10656126

RESUMO

Dental treatment of a nine-year old boy with Asperger syndrome is described. A "social story" is used to explain and perform the treatment.


Assuntos
Síndrome de Asperger , Comunicação , Assistência Odontológica para Crianças , Assistência Odontológica para a Pessoa com Deficiência , Criança , Relações Dentista-Paciente , Humanos , Masculino
13.
J Health Psychol ; 3(1): 149-60, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22021350

RESUMO

This Final Report of the European Federation of Professional Psychologists' Associations (EFPPA) Task Force on Health Psychology defines the nature and scope of health psychology and its possible future development to the year 2000 and beyond. Training needs and objectives are specified for professional health psychologists working in Europe. Practical and policy implications of medical progress and societal changes are discussed. The future development of health psychology as a profession depends on putting theory and policy into practice through the implementation of high quality training. Currently there are relatively few European countries where this has yet happened. Training programmes need to be introduced in all European countries within the framework of each member- country's national laws, regulations and practices.

14.
Ciba Found Symp ; 205: 175-82; discussion 183-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9189624

RESUMO

This paper describes the clinical, histological and genetic findings in individuals with amelogenesis imperfecta diagnosed in more than 50 families in the county of Västerbotten, northern Sweden. Using pedigree analysis, families with autosomal and X-linked inheritance as well as sporadic cases of amelogenesis imperfecta have been recognized. A clinical subclassification in eight different variants of amelogenesis imperfecta has been made. The gene defects have been identified for two of these variants and the chromosomal location has been established for a third variant.


Assuntos
Amelogênese Imperfeita/classificação , Amelogênese Imperfeita/genética , Cromossomos Humanos Par 4/genética , Cromossomo X/genética , Amelogênese Imperfeita/patologia , Mapeamento Cromossômico , Feminino , Ligação Genética , Humanos , Masculino , Epidemiologia Molecular , Suécia
15.
Genomics ; 39(2): 164-70, 1997 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9027503

RESUMO

Amelogenesis imperfecta (AI) is a clinically and genetically heterogeneous group of inherited enamel defects. We recently mapped a locus for autosomal dominant local hypoplastic amelogenesis imperfecta (AIH2) to the long arm of chromosome 4. The disease gene was localized to a 17.6-cM region between the markers D4S392 and D4S395. The albumin gene (ALB), located in the same interval, was a candidate gene for autosomal dominant AI (ADAI) since albumin has a potential role in enamel maturation. Here we describe refined mapping of the AIH2 locus and the construction of marker maps by radiation hybrid mapping and yeast artificial chromosome (YAC)-based sequence tagged site-content mapping. A radiation hybrid map consisting of 11 microsatellite markers in the 5-cM interval between D4S409 and D4S1558 was constructed. Recombinant haplotypes in six Swedish ADAI families suggest that the disease gene is located in the interval between D4S2421 and ALB. ALB is therefore not likely to be the disease-causing gene. Affected members in all six families share the same allele haplotypes, indicating a common ancestral mutation in all families. The AIH2 critical region is less than 4 cM and spans a physical distance of approximately 4 Mb as judged from radiation hybrid maps. A YAC contig over the AIH2 critical region including several potential candidate genes was constructed.


Assuntos
Amelogênese Imperfeita/genética , Mapeamento Cromossômico , Cromossomos Humanos Par 4 , Albuminas/genética , Cromossomos Artificiais de Levedura , Feminino , Marcadores Genéticos , Humanos , Masculino , Linhagem , Polimorfismo Genético , Recombinação Genética , Sitios de Sequências Rotuladas
16.
Burns ; 22(6): 455-8, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8884005

RESUMO

The quantitative assessment of the results of burn management is notoriously difficult. With the focus changing from survival to cosmetic and functional outcome, the scar assessments are increasingly important. The scar is a sum of the injury and all subsequent interventions on the way to healing. As such it is a complex structure, abnormal in its colour, depth, contour and pliability. To develop a quantitative system we believe it is vital to be able to track accurately an area of injury through time. Further, that physiological data acquired by a number of measurement tools be fused accurately to the morphologically correct information.


Assuntos
Queimaduras/complicações , Cicatriz/patologia , Adolescente , Cicatriz/diagnóstico por imagem , Cicatriz/etiologia , Humanos , Masculino , Ultrassonografia , Cicatrização
17.
Arch Oral Biol ; 41(8-9): 893-900, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9022927

RESUMO

Amelogenesis imperfecta (AI) is a group of hereditary enamel defects, characterized by large clinical diversity. On the basis of differences in clinical manifestation and inheritance pattern, 14 different subtypes have been recognized. A locus for autosomal dominant AI (ADAI) of local hypoplastic type was recently mapped to the region between D4S392 and D4S395 on the long arm of chromosome 4. To test whether the chromosome 4 locus is responsible for other forms of AI as well, a linkage study was carried out with 17 families representing at least five clinical forms of ADAI. Admixture tests for heterogeneity performed with the marker D4S2456 gave statistical support for genetic heterogeneity of ADAI with the odds 78:1. Linkage to the ADAI locus on chromosome 4q (AIH2) could only be demonstrated with families expressing the local hypoplastic type, and there was no support for heterogeneity within that group of families. Furthermore, linkage could be excluded for five families with other clinical forms of ADAI. The data therefore demonstrated that ADAI is genetically heterogeneous, and that at least two loci for it exist.


Assuntos
Amelogênese Imperfeita/genética , Cromossomos Humanos Par 4/genética , Amelogênese Imperfeita/classificação , Amelogenina , Distribuição de Qui-Quadrado , Proteínas do Esmalte Dentário/genética , Feminino , Genes Dominantes , Heterogeneidade Genética , Ligação Genética , Humanos , Escore Lod , Masculino , Linhagem , Cromossomo X/genética
18.
Genomics ; 26(1): 159-62, 1995 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-7782077

RESUMO

Formation of tooth enamel is a poorly understood biological process. In this study we describe a 9-bp deletion in exon 2 of the amelogenin gene (AMGX) causing X-linked hypoplastic amelogenesis imperfecta, a disease characterized by defective enamel. The mutation results in the loss of 3 amino acids and exchange of 1 in the signal peptide of the amelogenin protein. This deletion in the signal peptide probably interferes with translocation of the amelogenin protein during synthesis, resulting in the thin enamel observed in affected members of the family. We compare this mutation to a previously reported mutation in the amelogenin gene that causes a different disease phenotype. The study illustrates that molecular analysis can help explain the various manifestations of a tooth disorder and thereby provide insights into the mechanisms of tooth enamel formation.


Assuntos
Amelogênese Imperfeita/genética , Proteínas do Esmalte Dentário/genética , Mutação , Sinais Direcionadores de Proteínas/genética , Amelogênese Imperfeita/etiologia , Amelogenina , Sequência de Bases , Esmalte Dentário/fisiologia , Éxons , Feminino , Deleção de Genes , Humanos , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase
19.
Hum Mol Genet ; 3(9): 1621-5, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7833920

RESUMO

Amelogenesis imperfecta (AI), is an inherited odontological disease which affects the formation of enamel. We report a linkage analysis study performed on three Swedish families, where the affected members had an autosomal dominant variant of AI (ADAI) clinically characterized as local hypoplastic. Significant linkage to microsatellite markers on chromosome 4q were obtained. Recombinations localized the ADAI locus to a chromosome region which contains both a locus for the dental disorder dentinogenesis imperfecta and the albumin gene. Serum albumin has been suggested to play a role in enamel formation, and the albumin gene is therefore a candidate gene for this genetic disease.


Assuntos
Amelogênese Imperfeita/genética , Cromossomos Humanos Par 4 , Amelogênese Imperfeita/patologia , Mapeamento Cromossômico , DNA Satélite/genética , Hipoplasia do Esmalte Dentário/genética , Hipoplasia do Esmalte Dentário/patologia , Feminino , Genes Dominantes , Ligação Genética , Marcadores Genéticos , Humanos , Escore Lod , Masculino , Linhagem , Fenótipo , Recombinação Genética , Suécia
20.
Scand J Dent Res ; 102(4): 193-7, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8091117

RESUMO

The aim of the present investigation was to determine the mineral distribution in the enamel of teeth with amelogenesis imperfecta (AI) by quantitative microradiography. A further aim was to correlate the findings to clinical manifestations and inheritance patterns for AI. Included in the study were a total of 29 teeth with AI, 28 primary and one permanent, and seven unaffected teeth, five primary and two permanent. Quantitative microradiography was applied to sagittally ground sections, 70-90 microns, of the teeth. The mineral content of the enamel, expressed as percentage by volume, was lower in most of the teeth with AI than in the unaffected teeth. The largest range for the mineral distribution was found in the enamel of the variants clinically characterized by hypomineralization. These teeth showed a mineral distribution pattern that reflected an extremely low mineral content in the bulk of the enamel. In the AI teeth clinically characterized by hypoplasia, the mineral distribution pattern was similar to that of the unaffected teeth, although with larger local variations in mineral content. Apart from the teeth connected with X-linked inheritance, no differences were found among teeth with similar clinical variants connected with different inheritance patterns.


Assuntos
Amelogênese Imperfeita/metabolismo , Esmalte Dentário/metabolismo , Minerais/metabolismo , Amelogênese Imperfeita/genética , Amelogênese Imperfeita/patologia , Criança , Esmalte Dentário/química , Esmalte Dentário/patologia , Hipoplasia do Esmalte Dentário/metabolismo , Hipoplasia do Esmalte Dentário/patologia , Ligação Genética , Humanos , Microrradiografia , Minerais/análise , Dente/química , Dente/metabolismo , Dente/patologia , Dente Decíduo/química , Dente Decíduo/metabolismo , Dente Decíduo/patologia , Cromossomo X
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