RESUMO
Finite element analysis was used to compare the effect of different implant lengths on atrophic mandible with full-arch fixed prostheses. Four models were constructed with different implant lengths: 4, 6, 8 and 10 mm. A 100-N occlusal load was applied. The stress at the bone level, implant, and prosthetic components were obtained. Similar behavior was observed for all groups, except for 4 mm, which showed more discrepant values ââfor all prosthetic components. Although longer implants presented better biomechanical behavior, the 4 mm implant seems to be a viable alternative for severely atrophic mandibles, however, further studies need to be carried out.
Assuntos
Implantes Dentários , Planejamento de Prótese Dentária , Prótese Dentária Fixada por Implante , Análise do Estresse Dentário , Mandíbula/cirurgia , Boca Edêntula/cirurgia , Atrofia , Fenômenos Biomecânicos , Parafusos Ósseos , Dente Suporte , Análise de Elementos Finitos , Humanos , Suporte de CargaRESUMO
Background. Genetic polymorphisms in certain cytokines and chemokines have been investigated to understand why some individuals display implant flaws despite having few risk factors at the time of implant. Purpose. To investigate the association of genetic polymorphisms in interleukin- (IL-) 10 [-1082 region (A/G)] and RANKL [-438 region (A/G)] with the failure of dental implants. Materials and Methods. This study included 90 partially edentulous male and female patients who were rehabilitated with a total of 245 Straumann dental implants. An implant was considered a failure if any of the following occurred: mobility, persistent subjective complaint, recurrent peri-implant infection with suppuration, continuous radiolucency around the implant, probing depth ≥ 5 mm, and bleeding on probing. Buccal mucosal cells were collected for analysis of RANKL438 and IL-10. Results. The implant success rate in this population was 34.4%. The mutant allele (G) in RANKL had an incidence of 52.3% and mutant allele (A) in IL-10 was observed in 37.8%. No statistically significant difference was detected between the failure of the implant and the genotypes and allelic frequencies. Conclusion. No association was detected between the genetic polymorphisms of RANKL (-438) and IL-10 (-1082) and the failure of dental implants in the population studied.
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We present a family case series with 10 individuals having nevoid basal cell carcinoma syndrome (NBCCS) with a 10-year follow-up. All articles published in the literature between 1967 and 2011 on familial Gorlin-Goltz syndrome in any language were surveyed to determine the mapping of cases per country of occurrence of this disease. All patients in the present series were presented with calcification of the falx cerebri, mild hypertelorism, and frontal bossing. Odontogenic keratocystic tumors, palmar and plantar pits, and multiple basal cell carcinomas occurred in 90, 40, and 20%, respectively, of the patients. One of the patients died of skin cancer. Diagnosis of odontogenic keratocyst tumors was confirmed by histopathological examination. NBCCS is a rare autosomal dominant cancer predisposition syndrome; it is important to recognize it when a patient has multiple odontogenic keratocyst tumors because life-long monitoring is essential for patient management.
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CONTEXT: Ameloblastomas are benign tumors of the jaws with locally invasive capacity. AIM: The aim of this study was to review 112 cases of ameloblastoma seen over an 18-year period (1992-2009) at the Pernambuco Dental School, University of Pernambuco and at Federal University of Sergipe, in the northeast region of Brazil. MATERIALS AND METHODS: THE FOLLOWING DATA WERE SELECTED FOR ANALYSIS: age, gender, race, site distribution, radiographic appearance, association with an impacted tooth, size, presence of symptoms, clinicopathologic subtypes and recurrence. SETTINGS AND DESIGN: In this retrospective study, Pearson's χ(2) test and t-test were employed. The critical level of significance was set at P < 0.05. RESULTS: The mean age of the patients at presentation was 35.1 ± 16.8 years with a slight female preference. The peak prevalence was in the 11- to 20-year age group and declined with increasing age. Total 75 patients were black and 37 were white, for a 2:1 black: white ratio. The location of the ameloblastomas showed a marked predominance in the mandible (84.8%) and 69% of the cases presented with a multilocular radiographic appearance. The tumor was associated with an embedded tooth in 14 cases (12.7%): nine unilocular and five multilocular ameloblastomas. The maximum radiological extension of the lesions on panoramic radiographs was 0.5-20 cm (mean ± SD: 5.2 ± 3.3 cm) and most cases were symptom-free (75.9%). Solid/multicystic ameloblastoma was the most common clinicopathologic subtype. There was an association between the clinicopathologic subtypes and radiographic appearance (P < 0.001). Recurrence was observed in 13.3% of cases. CONCLUSION: We propose that racial factors may have strong influence on the incidence of ameloblastomas in the northeast region of Brazil, since most people have African descent. Data related to gender, location, radiographic appearance, size, symptoms, clinicopathologic subtypes and recurrence were similar to previous studies conducted in various parts of the world.
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Condylar fracture osteosynthesis is nowadays commonly practiced, but only a few studies report the intraoral approach with angulated devices. Subcondylar fractures with little or lateral displacement can be treated using an intraoral approach with satisfactory results. The advantages of this approach are the absence of visible scars, the avoidance of facial nerve injury inherent to the extraoral approach, quick access to the fracture, and a reduced risk of infection. The authors report a case of subcondylar fracture treated through an intraoral approach. Despite the considerable lateral dislocation of the condyle, treatment consisted of the reduction of the fracture and osteosynthesis with a trapezoidal condylar plate using an intraoral surgical approach.
Assuntos
Fixação Interna de Fraturas/métodos , Côndilo Mandibular/lesões , Fraturas Mandibulares/cirurgia , Adulto , Humanos , Masculino , Côndilo Mandibular/diagnóstico por imagem , Fraturas Mandibulares/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: The objective of the present study was to conduct a computational, laboratory-based comparison of the biomechanical stability of 2.0 fixation locking plates with different profiles in Class III atrophic mandibular fractures using 3-dimensional finite element analysis. MATERIALS AND METHODS: Three-dimensional finite element models simulating Class III atrophic mandibular fractures were constructed. The models were divided into 4 groups according to plate thickness (1.0, 1.5, 2.0, and 2.5 mm). Fractures were simulated in left mandibular bodies, and 3 locking screws were used on each side of each fracture for fixation. Bite forces of approximately 63 N were simulated in the incisor and molar regions of the mandibles in finite element models. RESULTS: The level of compressive strain on the bone around the screw was within the physiological limit. No significant difference was observed in the displacement of bone segments in the fracture region. Von Mises stress was higher during simulated bites in the molar region for plates with thicknesses of 1.0 mm. Plate tension values were below the level required for permanent deformation or fracture in all models. The 2.5-mm-thick plate presented better biomechanical performance than all other plates. The 2.0-mm-thick plate also showed satisfactory results and adequate safety limits. CONCLUSION: Large-profile (2.0-mm-thick) locking plates showed better biomechanical performance than did 1.0- and 1.5-mm-thick plates and can be considered an alternative reconstruction plate for the treatment of Class III atrophic mandibular fractures.
Assuntos
Placas Ósseas , Análise de Elementos Finitos , Imageamento Tridimensional/métodos , Mandíbula/patologia , Fraturas Mandibulares/cirurgia , Idoso , Atrofia , Fenômenos Biomecânicos , Força de Mordida , Parafusos Ósseos , Simulação por Computador , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico/métodos , Arco Dental/patologia , Módulo de Elasticidade , Desenho de Equipamento , Feminino , Fixação Interna de Fraturas/instrumentação , Humanos , Processamento de Imagem Assistida por Computador/métodos , Incisivo/patologia , Fraturas Mandibulares/patologia , Músculos da Mastigação/patologia , Modelos Biológicos , Dente Molar/patologia , Estresse Mecânico , Propriedades de SuperfícieRESUMO
BACKGROUND: The aim of the present study was to analyze hemodynamic changes after the administration of either 2% lidocaine with epinephrine 1:100,000 (L100) or 4% articaine with epinephrine 1:200,000 (A200) in the surgical removal of symmetrically positioned lower third molars. METHODS: A prospective, randomized, double-blind, clinical trial was carried out involving 43 patients. Each patient underwent 2 surgeries on different occasions-one under local anesthesia with L100 and the other with A200. The following parameters were assessed at 4 different times: systolic, diastolic, and mean blood pressure; heart rate; oxygen saturation; rate pressure product (RPP); and pressure rate quotient (PRQ). RESULTS: No hypertensive peak was observed in systolic, diastolic, and mean blood pressure at any evaluation time. Moreover, the type of anesthetic solution did not affect diastolic blood pressure, oxygen saturation or PRQ during the surgeries. Statistically significant differences between groups were detected with regard to heart rate and RPP (P < 0.05). CONCLUSIONS: The epinephrine concentration (1:100,000 or 1:200,000) and local anesthetic solutions used (2% lidocaine or 4% articaine) influenced hemodynamic parameters without perceptible clinical changes in healthy patients undergoing lower third molar removal.
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Anestésicos Locais/farmacologia , Carticaína/farmacologia , Epinefrina/farmacologia , Hemodinâmica/efeitos dos fármacos , Lidocaína/farmacologia , Dente Serotino/cirurgia , Dente Impactado/cirurgia , Vasoconstritores/farmacologia , Adolescente , Adulto , Anestésicos Locais/administração & dosagem , Carticaína/administração & dosagem , Método Duplo-Cego , Epinefrina/administração & dosagem , Feminino , Humanos , Lidocaína/administração & dosagem , Masculino , Estudos Prospectivos , Vasoconstritores/administração & dosagemRESUMO
BACKGROUND: An increase in blood pressure during dental treatment has been investigated with regard to potential medical risks since previous studies suggest that dental procedures may cause stress to the patient and, consequently, the cardiovascular system. The aim of the present study was to analyze hemodynamic changes following the administration of either 2% lidocaine (L100) or 4% articaine (A100) (both with epinephrine 1:100,000) in the surgical removal of symmetrically positioned lower third molars. METHODS: A prospective, randomized, double-blind, clinical trial was carried out involving 47 patients. Each patient underwent 1 surgery at each of 2 appointments--one under local anesthesia with L100 and the other with A100. The following parameters were assessed at 4 different times: systolic, diastolic, and mean blood pressure; heart rate; oxygen saturation; rate pressure product; and pressure rate quotient. RESULTS: No hypertensive peak was observed in systolic, diastolic, and mean blood pressure at any evaluation time. Moreover, the type of anesthetic solution did not affect diastolic blood pressure, heart rate, or oxygen saturation during the surgeries. The pressure rate quotient was the only parameter to exhibit statistically significant differences between groups at different evaluation times (P < 0.05). CONCLUSIONS: The hemodynamic parameters evaluated in third molar surgery with 2% lidocaine and 4% articaine (both with epinephrine 1:100,000) did not show significant differences.