RESUMO
Aim: To analyze the stress distribution at the peri-implant bone tissue of mandible in full-arch implant-supported rehabilitation using a different number of implants as support. Methods: Three-dimensional finite element models of full-arch prosthesis with 3, 4 and 5 implants and those respective mandibular bone, screws and structure were built. ANSYS Workbench software was used to analyze the maximum and minimum principal stresses (quantitative analysis) and modified von Mises stress (qualitative analysis) in peri-implant bone tissue after vertical and oblique forces (100N) applied to the structure at the cantilever site (region of the first molars). Results: The peak of tensile stress values were at the bone tissue around to the distal implant in all models. The model with 3 implants presented the maximum principal stress, in the surrounding bone tissue, higher (~14%) than the other models. The difference of maximum principal stress for model with 4 and 5 implants was not relevant (~1%). The first medial implant of the model with 5 implants presented the lower (17%) stress values in bone than model with 3 implants. It was also not different from model with 4 implants. Conclusion: Three regular implants might present a slight higher chance of failure than rehabilitations with four or five implants. The use of four implants showed to be an adequate alternative to the use of classical five implants
Assuntos
Prostodontia , Implantes Dentários , Análise de Elementos Finitos , Reabilitação BucalRESUMO
Abstract Introduction: A key step of cancer development is the progressive accumulation of genomic changes resulting in disruption of several biological mechanisms. Carcinoma ex-pleomorphic adenoma (CXPA) is an aggressive neoplasm that arises from a pleomorphic adenoma. CXPA derived from a recurrent PA (RPA) has been rarely reported, and the genomic changes associated with these tumors have not yet been studied. Objective: We analyzed CXPA from RPAs and RPAs without malignant transformation using array-comparative genomic hybridization (array-CGH) to identify somatic copy number alterations and affected genes. Methods: DNA samples extracted from FFPE tumors were submitted to array-CGH investigation, and data was analyzed by Nexus Copy Number Discovery Edition v.7. Results: No somatic copy number alterations were found in RPAs without malignant transformation. As for CXPA from RPA, although genomic profiles were unique for each case, we detected some chromosomal regions that appear to be preferentially affected by copy number alterations. The first case of CXPA-RPA (frankly invasive myoepithelial carcinoma) showed copy number alterations affecting 1p36.33p13, 5p and chromosomes 3 and 8. The second case of CXPA-RPA (frankly invasive epithelial-myoepithelial carcinoma) showed several alterations at chromosomes 3, 8, and 16, with two amplifications at 8p12p11.21 and 12q14.3q21.2. The third case of CXPA-RPA (minimally invasive epithelial-myoepithelial carcinoma) exhibited amplifications at 12q13.3q14.1, 12q14.3, and 12q15. Conclusion: The occurrence of gains at chromosomes 3 and 8 and genomic amplifications at 8p and 12q, mainly those encompassing the HMGA2, MDM2, WIF1, WHSC1L1, LIRG3, CDK4 in CXAP from RPA can be a significant promotional factor in malignant transformation.
Resumo Introdução: Uma etapa fundamental do desenvolvimento do câncer é o acúmulo progressivo de alterações genômicas, resultando na ruptura de vários mecanismos biológicos. Carcinoma ex-adenoma pleomórfico (CXAP) é uma neoplasia agressiva que surge a partir de um adenoma pleomórfico. O CXAP derivado de um AP recorrente (APR) foi raramente relatado e, até o momento, as alterações genômicas associadas a esses tumores não foram estudados. Objetivo: Avaliar as diferenças entre os CXAPs decorrentes de APRs e os APRs sem transformações malignas usando hibridização genômica comparativa em microarrays (array Comparative Genomic Hibridization - aCGH) a fim de identificar alterações no número de cópias somáticas e os genes afetados. Método: Amostras de DNA extraídas de tumores provenientes de tecido emblocado em parafina foram submetidos à investigação com a técnica aCGH, e os dados foram analisados com o Nexus Copy Number Discovery Edition v.7. Resultados: Não observamos alterações no numero de cópias somáticas nos APRs sem transformação maligna. Quanto ao CXAP de APR, embora os perfis genômicos sejam exclusivos para cada caso, detectamos algumas regiões cromossômicas que pareciam ser preferencialmente afetadas por alterações no número de cópias. O primeiro caso de CXAP-APR (carcinoma mioepitelial francamente invasivo) apresentou alterações no numero de cópias afetando 1p36.33p13, 5p e cromossomos 3 e 8. O segundo caso de CXAP-APR (carcinoma epitelialmioepitelial francamente invasivo) apresentou várias alterações nos cromossomos 3, 8 e 16, com duas amplificações em 8p12p11.21 e 12q14.3q21.2. O terceiro caso de CXAP-APR (carcinoma epitelial-mioepitelial minimamente invasivo) apresentou amplificações em 12q13.3q14.1, 12q14.3, e 12q15. Conclusão: A ocorrência de ganhos de cromossomos 3 e 8, e as amplificações genômicas em 8p e 12q, principalmente aquelas que englobam os HMGA2, MDM2, WIF1, WHSC1L1, RG3, CDK4 no CXAP decorrente de APR podem ser fatores promocionais significativos para a transformação maligna.
Assuntos
Humanos , Masculino , Feminino , Adulto , Idoso , Neoplasias das Glândulas Salivares/genética , Transformação Celular Neoplásica/genética , Adenoma Pleomorfo/genética , Neoplasias das Glândulas Salivares/patologia , Transformação Celular Neoplásica/patologia , Adenoma Pleomorfo/patologia , Recidiva Local de NeoplasiaRESUMO
ABSTRACT Mesiodens are supernumerary teeth, commonly seen in the maxillary midline. Given their high frequency, dentist should be aware of the signs and symptoms of mesiodens and their appropriate treatment. This case report describes an 8-year-old girl with a radiographic image suggesting two unerupted mesiodens between the central incisors on the palate. The intraoral examination showed swelling in the anterior palatal region with no mucosa alteration. The supernumerary teeth were diagnosed by periapical radiograph and computed tomography. The objective of this study is to present the clinical importance and use of diagnostic images, such as periapical radiograph (Clark technique) or tomography.
RESUMEN. Un mesiodens es un diente supernumerario que comúnmente se presenta en la línea media maxilar. Dada la frecuencia con la que se presenta, el odontólogo general debe estar bien informado acerca de los signos y síntomas del mesiodens y del tratamiento adecuado. Este artículo relata el caso de una paciente de 8 años de edad, en cuyo examen radiográfico se observa una imagen sugestiva de dos mesiodens no erupcionados entre los incisivos centrales superiores. En la valoración intraoral se encontró una inflamación en la región palatina anterior, sin ninguna alteración en la mucosa. Los dientes supernumerarios se diagnostican mediante radiografía y tomografía computarizada. El objetivo de este trabajo es presentar la importancia clínica observada y la utilización de imágenes auxiliares para el diagnóstico, como la radiografía periapical (técnica de Clark) o la tomografía computarizada.
Assuntos
Anormalidades Dentárias , Cirurgia Bucal , Dente Supranumerário , MaxilaRESUMO
INTRODUCTION: A key step of cancer development is the progressive accumulation of genomic changes resulting in disruption of several biological mechanisms. Carcinoma ex-pleomorphic adenoma (CXPA) is an aggressive neoplasm that arises from a pleomorphic adenoma. CXPA derived from a recurrent PA (RPA) has been rarely reported, and the genomic changes associated with these tumors have not yet been studied. OBJECTIVE: We analyzed CXPA from RPAs and RPAs without malignant transformation using array-comparative genomic hybridization (array-CGH) to identify somatic copy number alterations and affected genes. METHODS: DNA samples extracted from FFPE tumors were submitted to array-CGH investigation, and data was analyzed by Nexus Copy Number Discovery Edition v.7. RESULTS: No somatic copy number alterations were found in RPAs without malignant transformation. As for CXPA from RPA, although genomic profiles were unique for each case, we detected some chromosomal regions that appear to be preferentially affected by copy number alterations. The first case of CXPA-RPA (frankly invasive myoepithelial carcinoma) showed copy number alterations affecting 1p36.33p13, 5p and chromosomes 3 and 8. The second case of CXPA-RPA (frankly invasive epithelial-myoepithelial carcinoma) showed several alterations at chromosomes 3, 8, and 16, with two amplifications at 8p12p11.21 and 12q14.3q21.2. The third case of CXPA-RPA (minimally invasive epithelial-myoepithelial carcinoma) exhibited amplifications at 12q13.3q14.1, 12q14.3, and 12q15. CONCLUSION: The occurrence of gains at chromosomes 3 and 8 and genomic amplifications at 8p and 12q, mainly those encompassing the HMGA2, MDM2, WIF1, WHSC1L1, LIRG3, CDK4 in CXAP from RPA can be a significant promotional factor in malignant transformation.
Assuntos
Adenoma Pleomorfo/genética , Transformação Celular Neoplásica/genética , Neoplasias das Glândulas Salivares/genética , Adenoma Pleomorfo/patologia , Adulto , Idoso , Transformação Celular Neoplásica/patologia , Feminino , Humanos , Masculino , Recidiva Local de Neoplasia , Neoplasias das Glândulas Salivares/patologiaRESUMO
Introdução: fibroma ossificante periférico (FOP) é uma reação hiperplásica que ocorre exclusivamente na gengiva e afeta frequentemente mulheres. Recorrência não é incomum e a presença de periodontite severa aumenta o risco de recidiva porque os sítios com envolvimento de furca ou defeitos ósseos podem dificultar a completa excisão da lesão. Este trabalho tem como objetivo relatar um caso de FOP associado a um defeito de furca Classe II em uma paciente com periodontite. Relato de caso: paciente do sexo feminino, 58 anos de idade, com recorrência de lesão hiperplásica do tecido gengival, que havia sido excisada há 6 meses e diagnosticada como FOP. A lesão apresentava-se como uma massa nodular assintomática na maxila posterior, não-ulcerada, eritematosa, séssil, de consistência firme e endurecida. O exame clínico também mostrou presença de periodontite como manifestação de doença sistêmica. No local da lesão estava presente profundidade de sondagem de 9mm, sangramento à sondagem e defeito de furca Classe II. Ressecção cirúrgica e meticulosa raspagem e alisamento radicular foram realizadas, tomando-se cuidado de remover completamente a lesão. Não houve recidiva da lesão após um ano de acompanhamento, com melhora nos parâmetros clínicos de saúde, tais como redução na profundidade de sondagem para 3mm, ausência de sangramento à sondagem, ganho de inserção clínica e fechamento da furca. Conclusão: dentro dos limites deste relato de caso, pode-se concluir que a ocorrência concomitante do FOP a um envolvimento de furca, devido às características anatômicas desta região, representa um desafio para os clínicos e aumenta o risco de recorrência.
Background: Peripheral ossifying fibroma (POF) is a hyperplastic inflammatory reaction that occurs exclusively on gingiva and affects women. Recurrence is not uncommon and the presence of severe periodontitis increases the recurrence risk because sites with furcation involvement or bone defects may complicate the total lesion removal. This paper aims to report a case of POF associated to a class II furcation in a patient with periodontitis. Case report: female patient, 58 years old, with recurrence of gingival tissue growth, which had been excised 6 months earlier and diagnosed as POF. The lesion presented as an asymptomatic nodular mass in the posterior maxilla, non-ulcerated, erythematous, sessile, firm, and non-tender. Clinical examination also showed presence of periodontitis as a manifestation of systemic diseases. At the lesion site was present probing depth of 9mm, bleeding on probing and Class II furcation defect. Surgical resection and meticulous scaling and root planing were performed, taking care to completely exscind the lesion. There was no recurrence of the lesion one year later, with improvement in health clinical parameters, such as reduction in probing depth to 3mm, no bleeding on probe, clinical attachment level gain and furcation closure. Conclusion: Within the limits of this case report, it can be concluded that when POF occurs concurrently with a furcation involvement, because of its anatomical features, it represents a challenge for clinicians and increases the recurrence risk.
