Amelogenesis Imperfecta Restorations Survival Rate: A Retrospective Study

@#Introduction: Amelogenesis imperfecta (AI) is a rare genetic disease affecting both dentitions. Factors such as age, socioeconomic status, dentition and AI type and severity should be taken into consideration in treatment planning. Aim: This retrospective study aimed to assess the survival rate of AI main restorative options and the effects of gender and dentition type. Methods: The study sample comprised 28 dental records of patients aged 5-17 years affected by AI (15 females, 13 males) and with anterior and/or posterior restoration in primary and/or permanent tooth/teeth. The fate of each restoration was classified into three categories: failed, withdrawn and censored and analyzed by the life table method of survival analysis. Results: Out of 233 restorations performed, the most frequently used restoration was preformed metal crowns (PMCs), followed by anterior composite, posterior composite, adhesive casting, Ketac fill and amalgam respectively. The two main restorations, PMCs and anterior composite were included in the statistical analysis. The survival rate of PMCs was significantly higher than anterior composite (p<0.001). The anterior composite restorations survived significantly longer in males (p<0.05). Females had significantly better survival rate of PMCs (p<0.05). There was no statistically significant effect of the operator group of restoration survival. Conclusion: The anterior composite restorations survived significantly longer in males and females had significantly better survival rate of PMCs than males.

Enfoque de Tratamiento de una Adolescente con Amelogénesis Imperfecta / Treatment Approach for an Adolescent with Amelogenesis Imperfecta

La amelogénesis imperfecta (AI) es un grupo de tras-tornos hereditarios, clínica y etiológicamente hete-rogéneos, derivados de mutaciones genéticas, que se caracterizan por anomalías cualitativas y cuanti-tativas del desarrollo del esmalte, pudiendo afectar la dentición primaria y/o permanente. El tratamiento del paciente con AI es complejo y multidiscliplinario; supone un desafío para el odontólogo, ya que por lo general están involucradas todas las piezas dentarias y afecta no solo la salud buco dental sino el aspecto emocional y psicológico de los pacientes. Con el obje-tivo de describir el tratamiento integral y rehabilita-dor realizado en una paciente con diagnóstico de AI tipo III, se reporta el caso de un adolescente de sexo femenino de 13 años, que concurrió en demanda de atención a la Cátedra de Odontología Integral Niños de la Facultad de Odontología de la Universidad de Buenos Aires (FOUBA), cuyo motivo de consulta fue la apariencia estética y la hipersensibilidad de sus pie-zas dentarias. Durante el examen clínico intraoral, se observó que todas las piezas dentarias presentaban un esmalte rugoso, blando, con irregularidades y una coloración amarronada, compatible con diagnóstico de Amelogénesis Imperfecta tipo III hipomineralizada. Conclusión: El tratamiento rehabilitador de la AI en los pacientes en crecimiento y desarrollo estará diri-gido a intervenir de manera integral y temprana para resolver la apariencia estética y funcional, evitar las repercusiones sociales y emocionales, y acompañar a los pacientes y sus familias (AU)

Amelogenesis imperfecta (AI) is a group of clinically and etiologically heterogeneous hereditary disorders, derived from genetic mutations, characterized by qualitative and quantitative anomalies of enamel development, which can affect primary and/or permanent dentition. The treatment of patients with AI is complex and multidisciplinary, it is a challenge for the dentist, since in general all the teeth are involved and it affects not only oral health but also the emotional and psychological aspect of the patients. Objective: To describe the comprehensive and rehabilitative treatment carried out in an adolescent patient with a diagnosis of type III AI. Case report: The case of a 13-year-old female patient, who required dental attention at the Department of Dentistry for Children of the School of Dentistry of the University of Buenos Aires, whose reason for consultation was esthetic appearance and hypersensitivity of her teeth. In the intraoral clinical examination, it was observed that all the teeth had rough, soft enamel, with irregularities and a brownish color, compatible with the diagnosis of type III hypomineralized Amelogenesis Imperfecta. Conclusion: Rehabilitative treatment of AI in growing and developing patients will be aimed at early and comprehensive intervention to resolve esthetic and functional appearance, avoid social and emotional repercussions and accompany patients and their families (AU)

Clinical management of Hypoplasic Amelogenesis Imperfecta: a challenge for multidisciplinary team. A case report / Manejo clínico de la amelogénesis imperfecta hipoplásica: un desafío para el equipo multidisciplinar. Reporte de un caso

Abstract Amelogenesis imperfecta (AI) refers to a group of rare genetic disorders that involve tooth development and are passed down through families. Hypoplasic AI phenotypes include the absence of enamel as a result of a defect in the secretory stage. This case report describes the diagnosis and treatment of a patient with hypoplastic AI. The clinical implications include sensitive teeth, functional problems, and aesthetic complaining. The diagnosis was done through history, clinical examination and imaging. The intervention was performed by Direct Resin Veneers. This treatment showed to improve occlusion, esthetics, and self-image of the teenager. The satisfactory clinical result has made it possible to avoid more invasive and expensive treatments.

RESUMEN La amelogénesis imperfecta (AI) se refiere a un grupo de trastornos genéticos raros que involucran el desarrollo de los dientes y se transmiten de padres a hijos. Los fenotipos de AI hipoplásicos incluyen la ausencia de esmalte como resultado de un defecto en la etapa secretora. Este reporte de caso clínico describe el diagnóstico y tratamiento de un paciente con AI tipo hipoplásica. Las implicaciones clínicas incluyen dientes sensibles, problemas funcionales y quejas estéticas. El diagnóstico se realizó mediante anamnesis, exploración clínica e imagenología. La intervención fue realizada con carillas directas de resina. Este tratamiento demostró mejoras en la oclusión, la estética y la autoimagen del adolescente. El resultado clínico satisfactorio permitió evitar tratamientos más invasivos y costosos.

Interdisciplinary Approach of Amelogenesis Imperfecta: 10 Years of Clinical Follow-Up / Abordagem Interdisciplinar da Amelogênese Imperfeita: 10 Anos de Acompanhamento Clínico

Amelogenesis imperfecta (AI) is an inherited disease that expresses a disorder in the development of enamel structure. In its mildest form, it promotes tooth color change; and in more severe cases, it presents a loss of enamel structure initiated during the eruption phase. Different AI manifestations can coexist in the same patient or in the same tooth, both in the primary and permanent dentures. In addition, several subtypes are described, characterized according to the variety of phenotype and genotype. Successful treatment requires early diagnosis and therapeutic solutions involving different dental specialties. Although some professionals prefer to postpone permanent rehabilitation until the development of complete permanent dentures, the aesthetic and functional impact of this disease in childhood and adolescence requires that restorative treatment be started as soon as possible. The proposed therapies demonstrate numerous challenges such as extreme dentinal sensitivity, difficulties installing and maintaining the orthodontic appliance and the need for restorative and prosthetic intervention in malformed teeth. This work aims to demonstrate the interaction between Orthodontics, Restorative Dentistry and Prosthesis in the treatment of a patient with AI, reporting the success of treatment involving aesthetics, function and well-being and the long-term benefit of this interdisciplinary approach for patients with this disease. (AU)

A amelogênese imperfeita (AI) é uma doença hereditária que expressa uma desordem no desenvolvimento da estrutura do esmalte. Na sua forma mais branda, promove alteração na cor dos dentes; e em casos mais severos, apresenta perda de estrutura do esmalte iniciada durante a fase de irrupção. Diferentes manifestações da AI podem coexistir no mesmo paciente ou no mesmo dente, tanto na dentadura decídua quanto na permanente. Além disso, são descritos diversos subtipos, caracterizados de acordo com a variedade do fenótipo e genótipo. O sucesso do tratamento requer diagnóstico precoce e soluções terapêuticas que envolvam diversas especialidades odontológicas. Embora alguns profissionais prefiram adiar a reabilitação definitiva até o desenvolvimento da dentadura permanente completa, o impacto estético e funcional desta doença na infância e adolescência exige que o tratamento restaurador seja iniciado o mais cedo possível. As terapias propostas demonstram inúmeros desafios como a sensibilidade dentinária extrema, as dificuldades para instalação e manutenção do aparelho ortodôntico e a necessidade de intervenção restauradora e protética em dentes com má formação. O presente trabalho tem como finalidade demonstrar a interação entre a Ortodontia, a Dentística Restauradora e a Prótese no tratamento de um paciente com AI, relatando o sucesso do tratamento envolvendo estética, função, bem estar e o benefício em longo prazo desta abordagem interdisciplinar para os portadores desta doença. (AU)

Amelogênese imperfeita do tipo hipoplásica: relato de dois casos familiares / Amelogénesis imperfecta del tipo hipoplásico: informe de dos casos familiares / Hypoplastic amelogenesis imperfecta: report of two family cases

RESUMO Introdução: Diariamente o cirurgião dentista se depara com diversos casos que exigem acurácia no diagnóstico inicial e atenção para o tratamento que irá ser proposto, uma dessas é a amelogênese imperfeita, que é uma rara alteração dentária de caráter hereditário. As características principais da amelogênese imperfeita são hipomineralização ou hipoplasia da matriz de esmalte, o que ocasiona descoloração, sensibilidade e fragilidade deste tecido, apresentando diferentes subtipos clínicos, sendo a variante hipoplásica a mais prevalente. Objetivo: Relatar dois casos de amelogênese imperfeita do tipo hipoplásica entre membros de uma mesma família, correlacionando-os. Apresentação do caso: O diagnóstico foi feito através dos exames clínico e radiográfico, além da correlação entre os achados clínicos encontrados em cada paciente e com outros familiares, sendo proposto um plano de tratamento multidisciplinar e consistente com a condição adequada. Conclusões: É importante para o cirurgião dentista estudar e conhecer essas alterações raras para poder estabelecer diagnóstico preciso. Além disso, deve-se ampliar a conduta clínica através de um planejamento individualizado e/ou familiar, tratando não apenas aspectos estéticos e funcionais, mas também psicológico e sociais(AU)

RESUMEN Introducción: Diariamente el cirujano dentista se enfrenta a varios casos que exigen precisión en el diagnóstico inicial y atención para el tratamiento que se propondrá, una de las cuales es la amelogénesis imperfecta, que es un rara alteración dental de carácter hereditario. Las características principales de la amelogénesis imperfecta son hipomeralización o hipoplasia de la matriz de esmalte, lo que ocasiona decoloración, sensibilidad y fragilidad de este tejido, con la presencia de diferentes subtipos clínicos, siendo la variante hipoplásica la más prevalente. Objetivo: Informar dos casos de amelogénesis imperfecta del tipo hipoplásica entre miembros de una misma familia, correlacionándolos. Presentación del caso: El diagnóstico se realizó a través de los exámenes clínicos y radiográficos, además de la correlación entre los hallazgos clínicos encontrados en cada paciente y con otros familiares, por lo que fue propuesto un plan de tratamiento multidisciplinario y consistente con la condición adecuada. Conclusiones: Es importante para el cirujano dentista que estudie y conozca estos cambios raros para poder establecer un diagnóstico preciso. Además, se debe ampliar la conducta clínica a través de una planificación individualizada y / o familiar, tratando no solo aspectos estéticos y funcionales, sino también psicológicos y sociales(AU)

ABSTRACT Introduction: Dental surgeons are confronted every day with several cases that require accuracy in the initial diagnosis and attention to the treatment that will be proposed. One of these is amelogenesis imperfecta, a rare hereditary tooth alteration. The main features of amelogenesis imperfecta are hypomineralization or hypoplasia of the enamel matrix resulting in discoloration, sensitivity and fragility of this tissue. Of the existing clinical subtypes, the hypoplastic variant is the most prevalent. Objective: Report and correlate two cases of hypoplastic amelogenesis imperfecta in members of the same family. Case presentation: The diagnosis was based on clinical and radiographic examination, as well as analysis of the correlation between the clinical findings obtained from each patient and other relatives. The treatment plan proposed was therefore multidisciplinary and appropriately consistent with the condition. Conclusions: It is important for dental surgeons to study and be aware of these rare changes to be able to establish an accurate diagnosis. On the other hand, clinical management should be broadened through individualized and/or family planning, paying attention not only to esthetic and functional aspects, but psychological and social as well(AU)

A rare neurodegenerative disorder with a novel mutation in ROGDI and Rett- like phenotype: Kohlschütter- Tönz syndrome

@#Kohlschütter-Tönz syndrome (KTZS) is a rare neurodegenerative disorder that presents with seizures, developmental delay, psychomotor regression, hypoplastic dental enamel morphology characteristic for amelogenesis imperfecta, and dysmorphologies. Genetic analysis has identified loss of function mutations within the coding region of the ROGDI and SLC13A5 genes in KTZS. In this report, we documented the clinical, radiological, electroencephalographic, and genetic results of a 3.5-year-old Turkish girl, born to nonconsanguineous parents, who was the first patient diagnosed with KTZS in Turkey. The patient presented with Rett syndrome-like phenotype, neurodevelopmental delay, refractory seizures, and amelogenesis imperfecta. After obtaining informed consent, chromosomal DNAwas extracted from the peripheral blood of our patient and her parents. To investigate the moleculardiagnosis of the patient, the clinical exome sequencing was performed. The Sanger sequencing analysiswas performed for all of the family members for the validation and segregation of this mutation. PubMed/Medline, Web of Science, and Google Scholar were also searched to find all of the publisheddata on KTZS. The literature comprises 18 published studies about KTZS. The genetic analysis of ourpatient revealed a novel homozygous c.201-1G>T mutation in the ROGDI gene. The same mutationwas also found to be heterozygous in her mother and father. The mutation caused alternative splicingof the ROGDI translation and resulted in a disruption of the ROGDI protein.

Gingival inflammation, enamel defects, and tooth sensitivity in children with amelogenesis imperfecta: a case-control study

Abstract Gingival conditions and tooth sensitivity of young patients with amelogenesis imperfecta lack in depth studies. This case-control study aimed to compare (1) the gingival inflammation, the presence of enamel defects, and tooth sensitivity in young patients with and without amelogenesis imperfecta and (2) to investigate if any difference exists between subtypes of amelogenesis imperfecta. Methodology We compared forty-two participants with amelogenesis imperfecta with forty-two controls matched for age, gender, and the number of examined sites. Based on interview, clinical examination, and intraoral photography, we collected data on periodontal conditions, enamel defects and the presence of tooth sensitivity. Comparison tests were performed to investigate if any difference existed between cases and controls; and among cases, between the different subtypes of amelogenesis imperfecta. We performed a post-hoc analysis for any significant difference observed. Results We observed more gingival inflammation, enamel defects and tooth sensitivity among cases (all p<0.05). Participants with hypocalcified amelogenesis imperfecta had more gingival inflammation, enamel defects, and tooth sensitivity than patients with the hypoplastic and hypomature subtypes (all p<0.05). After adjustment for dental plaque, gingival inflammation was associated with the presence of amelogenesis imperfecta (OR (95%CI) = 1.14 (1.05; 1.24). p<0.01). Conclusion Gingival inflammation, enamel defect and tooth sensitivity are more frequently observed among young patients with amelogenesis imperfecta, and more specifically among children with the hypocalcified subtype.

Tratamiento conservador de un adolescente con amelogénesis imperfecta / Conservative treatment for an adolescent with amelogenesis imperfecta

RESUMEN: La amelogénesis imperfecta es un trastorno hereditario que afecta la formación del esmalte presentándose en dentición decidua y permanente. Existen numerosas clasificaciones, donde la amelogénesis imperfecta hipoplásica presenta las siguientes características clínicas: reducción del espesor del esmalte, coloración entre amarillo y marrón, superficie rugosa y falta de contacto interproximal. Estos pacientes reportan niveles más altos de evitación social y angustia por lo que es imperativo realizar un buen tratamiento rehabilitador. El presente artículo tiene como objetivo describir la secuencia terapéutica de un paciente adolescente diagnosticado con amelogénesis imperfecta hipoplásica utilizando la técnica modificada clear matrix con resinas compuestas.

ABSTRACT: Amelogenesis imperfecta is an inherited disorder affecting enamel formation in deciduous and permanent dentition. There are a large number of classifications, where hypoplastic amelogenesis imperfecta has the following clinical features: reduced enamel thickness, yellowish brown coloration, rough surface and lack of interproximal contact. These patients report the highest levels of social avoidance and distress, and it is therefore imperative to perform a good rehabilitative treatment. The objective of this paper is to describe the therapeutic sequence of an adolescent patient diagnosed with hypoplastic amelogenesis imperfecta, using the modified clear matrix technique with composite resins.

Rehabilitación protésica de una paciente con amelogénesis imperfecta / Prosthetic rehabilitation of a female patient with imperfect amelogenesis

Se describe el caso clínico de una paciente de 14 años de edad, quien fue remitida por el estomatólogo general integral al Centro de Rehabilitación de Prótesis Bucomaxilofacial de Santiago de Cuba para efectuar rehabilitación protésica. Al examen físico intrabucal se observaron dientes permanentes (11, 12, 13, 21, 22 y 23) de color anormal y manchas marronas en toda la superficie del esmalte, lo cual fue diagnosticado como una amelogénesis del tipo hipocalcificado. Se decidió realizar restauraciones individuales de coronas fundas provisionales de acrílico para mejorar su función y estética dental.

The case report of a 14 years patient is described who was referred by the general comprehensive stomatologist to the Oral and Maxillofacial Prosthesis Rehabilitation Center in Santiago de Cuba for prosthetic rehabilitation. Abnormal color and brown stains in the whole surface of the enamel of her permanent teeth were observed during the intraoral physical exam (11, 12, 13, 21, 22 and 23), which was diagnosed as an amelogenesis of hypocalcified type. It was decided to carry out individual restorations of provisional cases crowns with acrylic to improve their function and dental aesthetics.

Odontodisplasia Regional y Agenesia de Premolares. Reporte de un Caso / Regional Odontodysplasia and Premolar Agenesis. Case Report

RESUMEN: La odontodisplasia regional (OR) es una alteración en el desarrollo, no hereditario y que afecta tanto la dentición temporal como la dentición definitiva. Involucra a los tejidos mesodérmicos y ectodérmicos de los dientes lo que es condescendiente con hallazgos clínicos, radiográficos e histológicos. Su etiología aun es desconocida y se presenta mayoritariamente en mujeres. Clínicamente puede afectar al maxilar, a la mandíbula o ambas arcadas pero generalmente solo se ve comprometida una ellas, principalmente el más afectado es el hueso maxilar. Radiográficamente se observa una pobre diferencia entre los tejidos del esmalte y la dentina, siendo tejidos menos radiopacos que su contraparte sana generando un aspecto descrito como "diente fantasma". Histológicamente se observan zonas hipocalcificadas del esmalte con un orden de prismas irregulares mientras que la dentina se observa con un número reducido de túbulos dentinarios y de consistencia más fibrosa en su zona coronal. El tratamiento de la OR es controversial ya que su incidencia es baja y la literatura al respecto no es clara. El objetivo de este manuscrito, fue reportar un caso de OR y revisar la literatura relacionada. Presentamos un caso de OR en una paciente de 12 años que presenta ausencia de los dientes 2.4, 2.5 y 2.6; restos radiculares y agenesia de los dientes 3.5 y 4.5. Se describirán sus aspectos clínicos, radiográficos e histológicos. Se realizó una búsqueda sistemática en las siguientes bases de datos: Clínical key, Science Direct, PubMed y SciELO.

ABSTRACT: Regional odontodysplasia (RO) is a variation in the development; it is not hereditary and it affects both deciduous and permanent dentition. It involves the mesodermal and ectodermal tissues of dental pieces, and coincides with clinical, radiographic and histological findings. Its etiology is still unknown and it reportedly occurs mostly in women. Clinically it can affect the maxilla, mandible or both arches but generally only one is compromised, mainly the maxilla which is affected the most. Radiographically there is limited difference between enamel and dentin tissue, which is less radiopaque than their healthy counterpart, generating an aspect described as "phantom tooth". Histologically hypocalcified areas of the enamel are observed with an irregular order of prisms while the dentine is observed with a reduced number of dentinal tubules and more fibrous consistency in the coronal area. RO treatment is controversial since its incidence is low and the literature on these events is not clear. The aim of this manuscript was to report a case of RO and review related literature. We present a case of RO in a 12-year-old patient who presents absence of parts 2.4.2.5 and 2.6; radicular remains and agenesis of parts 3.5 and 4.5. Its clinical, radiographic and histological aspects are described. A systematic search was carried out in the following databases: Clinical key, Science Direct, PubMed and SciELO.

Genes involved in amelogenesis imperfecta. Part II / Genes involucrados en la amelogénesis imperfecta. Parte II

ABSTRACT Amelogenesis imperfecta (AI) is a condition of genetic origin that alters the structure of tooth enamel. AI may exist in isolation or associated with other systemic conditions as part of a syndromic AI. Our goal is to describe in detail the genes involved in syndromic AI, the proteins encoded by these genes, and their functions according to current scientific evidence. An electronic literature search was carried out from the year 2000 to December 2017, pre-selecting 1,573 articles, 40 of which were analyzed and discussed. The results indicate that mutations in 12 genes are responsible for syndromic AI: DLX3, COL17A1, LAMA3, LAMB3, FAM20A, TP63, CNNM4, ROGDI, LTBP3, FAM20C, CLDN16, CLDN19. These genes participate in the coding of proteins involved in phosphorylation, ion exchange, and production and degradation of the constituent elements of the mineral and organic phase of tooth enamel. The scientific evidence confirms that AI can be part of the syndrome and requires special attention from the medical-dental community.

RESUMEN La amelogénesis imperfecta (AI) es una condición de origen genético que altera la estructura del esmalte dental. La AI puede existir de manera aislada o asociada a otras afecciones sistémicas en el contexto de una AI sindrómica. El objetivo es describir de manera detallada los genes involucrados en las AI sindrómicas, las proteínas codificadas por estos genes y sus funciones de acuerdo a la evidencia científica actual. Se realizó una búsqueda electrónica de literatura desde el año 2000 hasta diciembre de 2017, después de lo cual se preseleccionaron 1.573 artículos, de los cuales 40 fueron analizados y discutidos. Los resultados indican que mutaciones en 12 genes son responsables de una AI sindrómica: DLX3, COL17A1, LAMA3, LAMB3, FAM20A, TP63, CNNM4, ROGDI, LTBP3, FAM20C, CLDN16, CLDN19. Estos genes están implicados en la codificación de proteínas que participan en la fosforilación, intercambio de iones, y producción y degradación de los elementos constituyentes de la fase mineral y orgánica del esmalte dental. La evidencia científica confirma que la AI puede ser parte del síndrome y amerita una especial atención de la comunidad médica-odontológica.

Immunohistochemical study of amelogenin binding proteins in an amelogenin point mutation mouse / Estudio inmunohistoquímico de proteínas de unión de la amelogenina en un ratón con mutación puntual de amelogenina

Amelogenin is one of the enamel matrices secreted by ameloblasts. A mutation of the amelogenin gene can cause hereditary dental enamel defects known as amelogenesis imperfecta (AI). Since lysosome-associated membrane protein-1 (LAMP-1), -3 (LAMP-3), and 78kDa glucose-related protein (Grp78) were identified as binding proteins of amelogenin, several studies have suggested the involvement of these binding proteins with the cell kinetics of ameloblasts in normal or abnormal conditions. The purpose of this study is to investigate the distribution of these amelogenin binding proteins in the ameloblast cell differentiation of mice with a point mutation of the amelogenin gene (Amelx*). The incisors of Amelx* mice had a white opaque color and the tooth surface was observed to be rough under a scanning electron microscope. Among the sequential ameloblast cell differentiation in the Amelx* mice, the shape of ameloblasts at the transition stage was irregular in comparison to those in wild-type (WT) mice. Immunostaining of Grp78 revealed that the whole cytoplasm of the transition stage ameloblasts was immunopositive for Grp78 antibody, while only the distal part of cell was positive in the WT mice. Furthermore, in the Amelx* mice, the cytoplasm of the transition stage ameloblasts was immunopositive for LAMP-1 and LAMP-3. These results suggest that Amelx* may cause the abnormal distribution of amelogenin binding proteins in the cytoplasm of ameloblasts.

La amelogenina es una de las matrices de esmalte secretadas por los ameloblastos. Una mutación del gen de amelogenina puede causar defectos hereditarios del esmalte dental conocidos como amelogénesis imperfecta (AI). Dado que la proteína de membrana asociada a lisosoma-1 (LAMP-1), -3 (LAMP-3) y la proteína relacionada con la glucosa de 78 kDa (Grp78) se identificaron como proteína de unión a amelogenina, varios estudios han sugerido la participación de estas proteínas con la cinética celular de los ameloblastos en condiciones normales o anormales. El objetivo del estudio fue investigar la distribución de LAMP-1, LAM-3 y Grp78 durante la diferenciación celular de ameloblastos de ratones con una mutación puntual del gen de amelogenina (Amelx*). Los incisivos de los ratones Amelx* presentaron un color blanco opaco y se observó en microscopio electrónico de barrido que la superficie del diente era áspera. La diferenciación celular secuencial y la forma de los ameloblastos en la etapa de transición en los ratones Amelx* fue irregular en comparación con los ratones silvestres (RS). La inmunotinción de Grp78 reveló que todo el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para el anticuerpo Grp78, mientras que solo la parte distal de la célula fue positiva en los ratones RS. Además, en ratones Amelx*, el citoplasma de los ameloblastos en etapa de transición fue inmunopositivo para LAMP-1 y LAMP-3. Estos resultados sugieren que Amelx* puede causar distribución anormal de proteínas de unión a amelogenina en el citoplasma de los ameloblastos.

Alteración del gen AMELX en amelogénesis imperfecta. Una breve revisión / Alteration of the AMELX gene in amelogenesis imperfecta. A brief review

Resumen La amelogénesis imperfecta es un grupo de trastornos de desarrollo del esmalte dental asociados principalmente con mutaciones en el gen AMELX. Clínicamente presenta diferentes fenotipos que afectan la estructura y función del esmalte, tanto de la dentición primaria como secundaria. El objetivo de este estudio fue realizar una revisión bibliográfica de las funciones y mutaciones de AMELX relacionadas con amelogénesis imperfecta. Se llevó a cabo una revisión bibliográfica en dos bases de datos: PubMed y Web of Science, usando las palabras clave “AMELX”, “amelogenina”, “amelogénesis imperfecta” y “mutación de AMELX”. Fueron revisados 40 artículos y se encontró que AMELX es el gen predominante en el desarrollo del esmalte dental y de la amelogénesis imperfecta, alterando la estructura de la amelogenina. En los últimos años se han descrito las características en el proceso de amelogénesis imperfecta con diferentes fenotipos de esmalte hipoplásico o hipomineralizado y se han reportado diferentes mutaciones, con lo que se ha determinado la secuenciación del gen y las posiciones de las mutaciones.

Abstract Amelogenesis imperfecta is a group of developmental disorders of the dental enamel that is mainly associated with mutations in the AMELX gene. Clinically, it presents different phenotypes that affect the structure and function of dental enamel both in primary and secondary dentition. The purpose of this study was to conduct a literature review on the AMELX functions and mutations that are related to amelogenesis imperfecta. A literature search was carried out in two databases: PubMed and Web of Science, using the keywords “AMELX”, “amelogenin”, “amelogenesis imperfecta” and “AMELX mutation”. Forty articles were reviewed, with AMELX being found to be the predominant gene in the development of dental enamel and amelogenesis imperfecta by altering the structure of amelogenin. In the past few years, the characteristics of the amelogenesis imperfecta process have been described with different phenotypes of hypoplastic or hypo-mineralized enamel, and different mutations have been reported, by means of which the gene sequencing and the position of mutations have been determined.

Diagnóstico y tratamiento integral en pacientes con Amelogénesis Imperfecta: reporte de un caso / Diagnóstico e tratamento integral em pacientes com Amelogênese Imperfeita: relato de um caso / Diagnosis and comprehensive treatment for patients with Amelogenesis Imperfecta. Case report

Objetivo: La Amelogénesis Imperfecta comprende un grupo heterogéneo de defectos del esmalte de origen genético, debidos a alteraciones en la formación del esmalte dentario, en calidad y/o cantidad. El diagnóstico se basa en la observación clínica, exámenes radiográficos, la historia familiar, el árbol genealógico y cuando es posible el diagnóstico genético. Se caracteriza por tener un amplio rango de presentaciones clínicas en ambas denticiones. Esta afección tiene un alto impacto en niños y adolescentes debido a que la carencia estética y la disfunción limitan su calidad de vida. La atención integral se convierte en un aspecto esencial y demanda una inteligente y necesaria interacción profesional, paciente y familia, la cual debe establecerse en forma temprana y de manera interdisciplinaria. Objetivo: Presentar un reporte de casocaso de un paciente de 11 años con Amelogénesis Imperfecta y diagnóstico clínico y radiográfico de tipo hipoplásico, apoyado en su historia familiar. El tratamiento integró varias etapas: uso de agentes remineralizantes a fin de restaurar los tejidos dentarios; ortodoncia para crear espacio para la erupción del canino retenido (13) y alineación de la arcada dentaria superior y rehabilitación dentaria con resinas compuestas y coronas metálicas fenestradas en oclusal. Conclusiones: El seguimiento por cinco años con una actitud muy positiva de la paciente hacia el mantenimiento de su salud, confirma que en el adolescente, una sonrisa saludable es importante en el desarrollo de la autoestima y las relaciones interpersonales.

A Amelogênese Imperfeita compreende um grupo heterogêneo de defeitos de esmalte de origem genética, que ocorre devido a alterações na formação de esmalte dentário, e podendo comprometer em qualidade e/ou quantidade do mesmo. O diagnóstico é baseado em observação clínica e radiográfica, história familiar, padrão genético familiar e quando possível, realização de uma investigação genética. Ela caracteriza-se por ter uma ampla gama de manifestações clínicas em ambas as dentições. Esta condição tem um alto impacto em crianças e em adolescentes, gerando um comprometimento social, a funçáo e consequentemente, limitando a qualidade de vida dos pacientes. O cuidado integral torna-se um aspecto essencial do tratamento, exigindo uma interação do profissional com o paciente e seus familiares, que deve ser estabelecida de forma precoce e interdisciplinar. Os objetivos do plano de tratamento devem abranger três aspectos: prevenção, restauração da estrutura dental e reabilitação estética. Objetivo: Paciente de 11 anos de idade, com amelogênese Imperfeita de tipo hipoplásico, segundo o diagnostico clínico e radiográfico e com base na história familiar. O tratamento foi realizado em diversas etapas: uso de agentes remineralizantes na remineralizacão de tecidos dentais, tratamento ortodóntico para criar espaço para a erupção do canino retido e o alinhamento da arcada dentária superior, e por último, a reabilitação com resinas compostas e coroas metálicas fenestradas na superfície oclusal. Conclusão: Durante cinco anos de acompanhamento, o paciente tem demonstrado uma atitude muito positiva em relação à manutenção de sua saúde, confirmando-se que na adolescência, um sorriso saudável é importante no desenvolvimento da autoestima e das relações interpessoais.

Amelogenesis Imperfecta is a diverse group of hereditary and heterogeneous enamel defects, due to alterations in the formation of dental enamel in quality and/or quantity. Diagnosis is based on clinical and radiological findings, family history, family tree, and genetic diagnosis when it is possible. It is characterized by a wide range of clinical presentations in both dentitions. This condition has a high impact on children and adolescents, generates a very disadvantageous social performance since aesthetic problems and dysfunction limit their quality of life. Comprehensive care becomes an essential aspect and it demands a close and necessary professional, patient and family interaction, which must be established early and in an interdisciplinary way. Objective: We present a patient with Amelogenesis Imperfecta, 11 years old, with a clinical and radiographic diagnosis of hypoplastic type, based on her family history. The treatment integrated several stages: use of remineralizing agents in order to restore Latinoamericanadental tissues, orthodontics to create space for the eruption of the retained canine (13), and the alignment of upper dental arch, and rehabilitation with composite resins and metal crowns fenestrated in occlusal. Conclusion: The five year follow- up, with a very positive attitude of the patient toward the maintenance of her health, suggests that in adolescence, a healthy smile is important in the development of self-esteem and interpersonal relationships.

Diversity of clinical, radiographic and genealogical findings in 41 families with amelogenesis imperfecta

Abstract Amelogenesis imperfecta (AI) is a group of enamel development disorders that alter the structure and chemical composition of the tissue. There is great variability in the clinical presentation; according to Witkop, AI can be categorized into 14 subtypes, which makes its diagnosis extremely complex. Objective: This study aimed to describe and determine the frequency of clinical and radiographic features and inheritance patterns found in 41 Chilean families diagnosed with diverse types of AI. Material and Methods: We analyzed the clinical records, photographs, pedigrees and radiographs of 121 individuals recruited between 2003 and 2016. All of the information was included in a database that was analyzed using the application Stata 14. Results: The 72 affected individuals had average age of 16 years, and no sex association with the presence of AI was found. The most frequent clinical subtypes were as follows: 43% hypomature, 25% hypoplastic, 21% hypomature/hypoplastic, 7% hypocalcified and 4% hypocalcified/hypoplastic. The number of severely affected teeth was 22, which occurred in the patients with hypocalcified and hypocalcified/hypoplasic AI who presented the highest number of damaged teeth. Caries and periodontal disease were found in 47 and 32% of the patients, respectively. Malocclusions were observed in 43% of the individuals with AI, with open bite being the most frequent. Radiographically, the thickness of the enamel decreased in 51% of the patients, and 80% showed decreased radiopacity of the enamel compared to that of dentin. Autosomal dominant inheritance pattern was found in 37% of the families with hypoplastic AI, and autosomal recessive pattern was present in 56% of the other clinical subtypes, but more frequently in those affected with hypomature and hypocalcified AI. Conclusion: Of the five clinical subtypes, autosomal recessive hypomature, autosomal dominant hypoplastic and autosomal recessive hypomature/hypoplastic AI were the most prevalent subtypes in this group.

Manejo integral del paciente con amelogénesis imperfecta

La Amelogénesis imperfecta (AI) es una alteración hereditaria que afecta el esmalte y, se caracteriza por hipomineralización o hipoplasia con decoloración, sensibilidad y fragilidad de los dientes. Se reporta el caso de un paciente de sexo femenino, de 5 años, no receptivo, es referido por emergencia a la Clínica Dental Cayetano Heredia debido a dolor intenso. Durante la anamnesis, el padre de familia refiere que tanto él, como el segundo hijo, poseen la misma alteración dentaria que su menor hija. Evaluación clínica radiográfica: el paciente presenta: lesiones cavitadas múltiples, necrosis pulpar, hipoplasia del esmalte. El diagnóstico presuntivo del defecto del esmalte: Amelogénesis Imperfecta. Se indica al padre de familia las alternativas de tratamiento, y este opta por un tratamiento integral bajo anestesia general. Habiendo extraído la pieza 7.5, como parte del tratamiento, ésta se lleva al servicio de patología para su análisis. Diagnóstico final: Amelogénesis Imperfecta tipo hipoplásico. Tratamiento: consiste en: profilaxis y aplicación de flúor barniz c/2 meses, pulpectomía, cementación de coronas de acero preformadas y restauraciones con resina. Discusión: Es importante averiguar si los miembros de la familia muestran alteraciones dentales (malformación hereditaria). Cuando se confirma el diagnóstico de AI, se debe considerar un tratamiento integral temprano. El tiempo de vida disminuida de las restauraciones directas en pacientes con AI, sugiere un mantenimiento constante de las restauraciones hasta que puedan realizarse restauraciones protésicas definitivas. En el caso de grandes destrucciones de dientes primarios, están indicadas coronas de acero inoxidable. Conclusiones: La AI es un trastorno hereditario que se debe diagnosticar en una etapa temprana y llevar un tratamiento integral con controles periódicos frecuentes. La utilización de coronas de acero preformadas para dientes posteriores y resinas para dientes anteriores podrían ser las mejores alternativas en pacientes que sufren AI.

Caracterización fenotípica del síndrome amelogénesis imperfecta­nefrocalcinosis: una revisión / Phenotypic characterization of amelogenesis imperfectanephrocalcinosis syndrome: a review

La Amelogénesis Imperfecta (AI) es alteración de la estructura y apariencia del esmalte dental de origen genético, puede presentarse como defecto aislado o sistémico. El Síndrome Amelogénesis imperfecta­Nefrocalcinosis (OMIM # 204690), también conocido como Síndrome Esmalte-Renal (ERS, en inglés), se caracteriza por la presencia de AI de tipo hipoplásico, hiperplasia gingival con mineralizaciones ectópicas, retraso y/o ausencia de la erupción dental y Nefrocalcinosis. Este síndrome es asociado a mutaciones autosómicas recesivas del gen FAM20A. El objetivo de esta revisión es exponer las características clínicas y fenotípicas de pacientes con el Síndrome Amelogénesis imperfecta­ Nefrocalcinosis. La obtención del material fue realizado mediante una búsqueda electrónica en las bases de datos MEDLINE (PubMed), EBSCO- Host y Scopus (ScienceDirect). Los resultados confirman la escasa frecuencia de casos clínicos con el Síndrome Amelogénesis imperfecta­Nefrocalcinosis. Las características clínicas y fenotípicas se exponen de manera clara, sencilla y precisa. Se recomienda a los odontólogos generales y odontólogos pediátricos que al diagnosticar una AI, particularmente de tipo hipoplásico, realicen una detallada historia médica personal - familiar y contemplen una interconsulta con el servicio de nefrología que permita diagnosticar o realizar un seguimiento al estado renal del paciente de una forma preventiva.

Amelogenesis Imperfecta (AI) is an alteration of the structure and appearance of dental enamel of genetic origin that can occur as an isolated or systemic defect. The Amelogenesis Imperfecta-Nefrocalcinosis Syndrome (OMIM # 204690), also known as Enamel-Renal Syndrome (ERS), is characterized by the presence of hypoplastic AI, gingival hyperplasia with ectopic mineralization, delayed tooth eruption and Nephrocalcinosis. This syndrome is associated with autosomal recessive mutations of the FAM20A gene. The aim of this review is to present the clinical and phenotypic characteristics of patients with the Amelogenesis Imperfecta-Nefrocalcinosis Syndrome. The material was obtained through an online search of MEDLINE database (PubMed), EBSCO-Host and Scopus (ScienceDirect). The results confirm the low frequency of clinical cases reported with Syndrome Amelogenesis Imperfecta-Nefrocalcinosis. The clinical and phenotypic characteristics were exposed in a clear, simple and precise way. It is recommended to general dentists and pediatric dentists that, when diagnosing an AI, particularly of hypoplastic type, they perform a detailed personal-family medical history and contemplate an interconsultation with the nephrology service that allows to diagnose or monitor the patient's renal status in a preventive style.

Three-dimensional assessment of enamel and dentine in mouse molar teeth during masseter muscle hypofunction / Evaluación tridimensional del esmalte y la dentina de dientes molares de ratones durante la hipofunción del músculo masetero

Background: Mouse molar is a widely used model for teeth development. However, the effect of masticatory function on enamel and dentine in adult individuals remains poorly understood. As reported, the unilateral masseter hypofunction induced by botulinum toxin type A (BoNTA) resulted in mandibular bone damage and signs of unilateral chewing in adult mice. Objective: We aimed to assess the amount of enamel and dentine in the first molar (M1) during the unilateral masseter hypofunction in mice, using high-resolution X-ray microtomography (µCT) as threedimensional approach. Materials and methods: Mandibles of adult BALB/c mice, located either in a Control-group (without intervention) or a BoNTA-group, were ex-vivo scanned using µCT. Treated individuals received each one BoNTA intervention in the right masseter, and saline solution in the left masseter (intra-individual control). Enamel and dentine from M1 were segmented, and volume, thickness and mesial root length were quantified. Results: Enamel volume from treated side resulted unchanged after 2 weeks of unilateral masseter hypofunction. No differences for enamel volume were found between both sides of control individuals, and between these and samples from hypofunctional side in BoNTA-group. Enamel volume from saline-injected side was reduced when compared with experimental side (p<0,01). No differences in dentine volume, thickness of enamel and dentine, and mesial root length were found for any group. Conclusion: The amount of enamel in hypofunctional molars remains unaffected after unilateral BoNTA intervention in the masseter, but contralateral side showed reduced enamel volume. Therefore, increased functional wearing during unilateral chewing after BoNTA intervention should be considered.

Introducción: El molar de ratón es utilizado como modelo de estudio en el desarrollo dental. El efecto de la función masticatoriasobre el tejido dental en individuos adultos aún se comprende. En ratones adultos, la hipofunción unilateral del masetero inducida por toxina botulínica tipo A (BoNTA) resultó en daño óseo mandibular y signos de masticación unilateral. Objetivo: Evaluamos la cantidad de esmalte y dentina en el primer molar (M1) durante la hipofunción unilateral del músculo masetero en ratones mediante análisis con microtomografía (µCT). Materiales y métodos: Las mandíbulas de ratones BALB/c adultos, del grupo Control (sin intervención) o el grupo BoNTA, fueron escaneadas ex-vivo con µCT. Los individuos tratados se inyectaron con BoNTA en el masetero derecho y con solución salina en el masetero izquierdo (control intra-individuo). El volumen y grosor de esmalte y dentina del M1, y la longitud de la raíz mesial fueron medidos. Resultados: No hubo cambios en el volumen del esmalte del lado tratado con BoNTA y en ambos lados del grupo Control, 2 semanas post-intervención. El esmalte del lado control intra-individuo se redujo comparado con el lado experimental (p< 0,01). No hubo cambios en el volumen de dentina, el grosor de esmalte y dentina o en longitud de la raíz mesial de ambos grupos. Conclusión: La cantidad de esmalte en los molares hipofuncionales no se afecta después de la inyección unilateral de BoNTA en masetero, pero si se reduce en el lado contralateral. Por lo tanto, se debe considerar un desgaste dental asimétrico durante esta intervención.

Genes involved in amelogenesis imperfecta. part i / Genes involucrados en la amelogénesis imperfecta. parte i

ABSTRACT Amelogenesis imperfecta (AI) refers to a group of genetic alterations of the normal structure of the dental enamel that disturbs its clinical appearance. AI is classified as hypoplastic, hypocalcified, and hypomaturation. These abnormalities may exist in isolation or associated with other systemic conditions in the context of a syndrome. This article is aimed to thoroughly describe the genes involved in non-syndromic AI, the proteins encoded by these genes and their functions according to current scientific evidence. An electronic literature search was carried out from the year 2000 to December of 2017, preselecting 1,573 articles, 63 of which were analyzed and discussed. The results indicated that mutations in 16 genes are responsible for non-syndromic AI: AMELX, AMBN, ENAM, LAMB3, LAMA3, ACPT, FAM83H, C4ORF26, SLC24A4, ITGB6, AMTN, MMP20, KLK4, WDR72, STIM1, GPR68. Future research with a translational approach will help to identify new mutations or genes, contributing to the evolution in the way of classifying, diagnosing and treating the various types of amelogenesis imperfecta.

RESUMEN La amelogénesis imperfecta (AI) constituye un grupo de alteraciones de la estructura normal del esmalte dental de origen genético que perturba su apariencia clínica. La AI se clasifica en hipoplásica, hipomadura e hipocalcificada. Estas anomalías pueden existir de manera aislada o asociada a otras afecciones sistémicas en el marco de un síndrome. En el presente artículo se pretende describir de manera detallada los genes involucrados en la AI no sindrómica, las proteínas codificas por estos genes y sus funciones, de acuerdo a la evidencia científica actual. Se realizó una búsqueda electrónica de literatura desde el año 2000 hasta diciembre de 2017, haciendo una preselección de 1573 artículos, de los cuales 63 fueron analizados y discutidos. Los resultados indicaron que las mutaciones en 16 genes son responsables de la AI no sindrómica: AMELX, AMBN, ENAM, LAMB3, LAMA3, ACPT, FAM83H, C4ORF26, SLC24A4, ITGB6, AMTN, MMP20, KLK4, WDR72, STIM1, GPR68. Las futuras investigaciones abordadas desde la visión translacional ayudarán a identificar nuevas mutaciones o nuevos genes, lo cual contribuirá a la evolución en la manera de clasificar, diagnosticar y tratar los diferentes tipos de amelogénesis imperfecta.

Desafios no diagnóstico e tratamento da amelogênese imperfeita: relato de caso / Challenges in the diagnosis and treatment of amelogenesis imperfecta: case report

A amelogênese imperfeita é uma alteração genética que acomete a morfologia do esmalte dentário, podendo ocorrer na dentição decídua e/ou permanente. Por apresentar um amplo espectro clínico é de suma importância um diagnóstico precoce para um correto planejamento odontológico. Diante disso, objetivou-se apresentar o caso de uma criança portadora de amelogênese imperfeita, incluindo o diagnóstico e os tratamentos executados, por um período de 4 anos. Paciente AHM, sexo feminino, 7 anos, procurou o Centro de Saúde Veiga de Almeida para acompanhamento odontológico de rotina. Apresentava dentição mista hígida e alterações de cor na coroa dentária nos incisivos e molares permanentes. Nesse momento foi diagnosticada como portadora de hipomineralização de molares e incisivos. Após a erupção dos demais dentes permanentes e o acometimento de praticamente todos os elementos, a criança foi diagnosticada como portadora de amelogênese imperfeita. Durante o período de tratamento foram realizados diversos procedimentos, entre eles restaurações, microabrasão, facetas em resina composta e coroa do tipo onlay. Pode-se concluir que o cirurgião-dentista deve estar atento quanto aos sinais e sintomas dos pacientes portadores de amelogênese imperfeita, juntamente com possíveis alterações emocionais que acometem esses pacientes. O tratamento executado foi considerado um sucesso, uma vez que as queixas da paciente foram atendidas através de um tratamento odontológico adequado capaz de restabelecer a função e a estética da criança.

Amelogenesis imperfecta is a genetic alteration that affects the dental enamel morphology, and may occur in the deciduous and/or permanent dentition, with or without systemic involvement. For presenting a broad clinical spectrum of paramount importance is a prior diagnosis for a correct dental planning. The objective was to present the report of a child with amelogenesis imperfecta, including diagnosis and treatments performed, for a period of 4 years. Patient AHM, female, 7 years, sought the Veiga de Almeida Health Center for routine dental follow-up. She presented mixed dentition with color enamel alteration in the dental crown on the permanent and molar incisors. At this moment she was diagnosed as having molar-incisive hypomineralization. After the eruption of the remaining teeth and the involvement of almost al the elements, the child was diagnosed as having amelogenesis imperfecta. During the treatment period, restorations, microabrasion, composite resin facets and onlay type crown were performed. It can be concluded that the dental surgeon should be aware of the signs and symptoms of patients with imperfect amelogenesis. The treatment performed was considered a success at a time and the patient complaints were answered, receiving adequate dental treatment and restoration of the child's function and aesthetics.