Mutagenicity and cytotoxicity in patients submitted to ionizing radiation A comparison between cone beam computed tomography and radiographs for orthodontic treatment

Objectives: To evaluate and compare mutagenicity (micronucleus) and cytotoxicity (karyorrhexis, pyknosis, and karyolysis) in exfoliated buccal mucosa cells of children following cone beam computed tomography (CBCT) or conventional radiograph exposure necessary for orthodontic planning.Materials and Methods: A total of 49 healthy children were submitted to CBCT or a conventional orthodontic radiographic protocol; they were divided into two groups based on exam: CBCT (n = 24) and Radiographic Set (n = 25) groups. the micronucleus test in the exfoliated buccal mucosa cells was applied.Results: There was not a statistically significant difference (P > .05) found between the number of micronucleated buccal mucosa cells (MNC) before and after exposure to radiation in either group, showing that neither group experienced a mutagenic effect. However, radiation did cause other nuclear alterations closely related to cytotoxicity, including karyorrhexis, pyknosis, and karyolysis, in both groups (P < .05). the CBCT group presented a greater increase in cell death than was noted in the Radiographic Set group (P < .044).Conclusion: According to the micronucleus test, mutagenicity was not induced by the CBCT or the conventional radiographs, but cytotoxicity was verified after these exams, especially after CBCT. That might have happened once the CBCT group received a greater radiation dose than the Radiographic Set group as a result of the protocols used in orthodontic planning for this study. (Angle Orthod. 2013;83:104-109.)Univ Fed Rio de Janeiro, Dept Orthodont, BR-21941617 Rio de Janeiro, RJ, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, São Paulo, BrazilWeb of Scienc

Cone-Beam Computed Tomography and Radiographs in Dentistry: Aspects Related to Radiation Dose

Introduction. The aim of this study was to discuss the radiation doses associated with plain radiographs, cone-beam computed tomography (CBCT), and conventional computed tomography (CT) in dentistry, with a special focus on orthodontics. Methods. A systematic search for articles was realized by MEDLINE from 1997–March 2011. Results. Twenty-seven articles met the established criteria. The data of these papers were grouped in a table and discussed. Conclusions. Increases in kV, mA, exposure time, and field of view (FOV) increase the radiation dose. The dose for CT is greater than other modalities. When the full-mouth series (FMX) is performed with round collimation, the orthodontic radiographs transmit higher dose than most of the large FOV CBCT, but it can be reduced if used rectangular collimation, showing lower effective dose than large FOV CBCT. Despite the image quality, the CBCT does not replace the FMX. In addition to the radiation dose, image quality and diagnostic needs should be strongly taken into account

Could formaldehyde induce mutagenic and cytotoxic effects in buccal epithelial cells during anatomy classes?

Due to increased formaldehyde exposure, carcinogenic to humans, several researches have been studying the potential toxicity and the safe levels for human beings. The aim of this study was to investigate mutagenicity and cytotoxicity in buccal epithelial exfoliated cells (BEC) of students subjected to formaldehyde (FA) during anatomy classes. BEC were collected periodically from 17 volunteers of undergraduate programs, who had participated in practical anatomy classes, before and after FA exposure. Cells were stained according to Feulgen method and then micronucleus test was applied. A total of 1,500 cells were assessed per individual in this study for the micronucleus frequency and other parameters of cytotoxicity. There was statistically significant increase in number of micronucleated BEC after FA exposure (after 1 month p=.034 and after 3.5 months p=.017). However, FA exposure caused no significant increase in other nuclear alterations closely related to cytotoxicity (p?.05). FA induced mutagenicity during anatomy classes. Cell death increased, but it was not statistically significant. Efforts have to be made to improve air quality and reduce exposures during anatomy classes

2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011

Alterações produzidas na fala por contenções superiores ortodônticas - ensaio clínico randomizado prospectivo

Objetivo: Avaliar e comparar a influência das diferentes contenções ortodônticas superiores na fala e as percepções dos voluntários às diferentes condições provocadas pela sua utilização. Correlacionar as percepções entre si e com as dimensões do arco superior. Material e Métodos: Selecionou-se 21 (n) voluntários para utilizar 4 tipos de contenções removíveis superiores (Placa wrap-around convencional, em U e com orifício anterior e contenção termoplástica transparente-CTT) por 21 dias cada, com intervalos de 7 dias sem utilização entre elas. Durante a pesquisa, alguns voluntários desistiram ou não compareceram às avaliações, sendo excluídos. As percepções dos pacientes aos aparelhos foram avaliadas com a Escala Visual Analógica de 100 mm (n final=19), e correlacionou-se estas entre si. A avaliação da fala (n final=18) foi realizada em gravações de trechos vocais realizadas antes e imediatamente após a instalação das 4 contenções, assim como após 21 dias de uso destas. Para isto empregou-se a Análise Perceptiva Auditiva da fala e a Análise Acústica da frequência dos formantes F1 e F2 das vogais. Aplicou-se a ANOVA para dados repetidos e teste de Friedman com post hoc de Tukey, além das Correlações de Pearson e de Spearman para as avaliações. O nível de significância estatística estabelecido foi de 5%. Resultados: Os variados desenhos das contenções wrap-around não diferiram de forma significante em nenhuma das percepções e a CTT recebeu notas estatisticamente piores em todos os quesitos, com exceção da estética onde não diferiu estatisticamente das demais. Correlações positivas importantes foram encontradas entre alterações na fala e desconforto em todos os aparelhos. A interferência oclusal na CTT correlacionou-se muito positivamente a outras percepções, como alterações na fala e desconforto. Na avaliação perceptivo-auditiva, as alterações na fala aumentaram significantemente no momento imediato após a instalação do wrap-around com orifício e da CTT, e continuaram significantemente elevadas após 3 semanas. A frequência dos formantes das vogais foi prejudicada no momento inicial da instalação e as Alterações mantiveram-se presentes no wrap-around convencional, em U e na CTT após 3 semanas. Conclusões: A CTT prejudicou mais a fala que os wrap-around. Entre estes, os wrap-around convencional e em U interferiram menos na fala. O período de 3 semanas de uso dos aparelhos não foi totalmente suficiente para a readaptação da fala. A CTT foi pior classificada que as placas wrap-around em todas percepções avaliadas, exceto na estética, onde não diferiram significantemente. A cobertura oclusal da CTT pareceu ser a causadora da sua reprovação e das maiores alterações à fala nesta contenção. As dimensões do arco superior pouco influenciaram as percepções. Considerando as alterações na fala e as percepções dos pacientes, as contenções wrap-around apresentaram melhor desempenho e devem ser a primeira escolha quando a opção de contenção do arco superior for um aparelho removível.Objective: To evaluate and compare the influence of different upper removable orthodontic retainers on speech and volunteers\' perceptions to different conditions caused by their use. To correlate perceptions with each other and with upper arch dimensions. Material and Methods: 21 (n) volunteers were selected to use four types of upper removable retainers (conventional wrap-around, horseshoe-shaped wrap-around, wrap-around with an anterior \"hole\" and transparent thermoplastic retainer - TTR) for 21 days each, with intervals of 7 days without use between them. During the search, some volunteers dropped out or did not attend the evaluations and were excluded. Patients perceptions (final n=19) were evaluated with a visual analogue scale of 100 mm, and these were correlated with each other. Speech evaluation (final n=18) was performed in vocal excerpts recordings made before, immediately after and 21 days after the installation of each appliance, with Perceptual Auditory Analysis Auditory and Acoustic Analysis of formant frequencies F1 and F2 of the vowels. ANOVA for repeated measures and Friedman test with post hoc Tukey, in addition to Pearson and Spearman correlation for the evaluations were applied for statistics evaluation. The level of statistical significance was set at 5%. Results: Different designs of wrap-around retainers did not differ significantly in any of the perceptions and TTR received significantly worse grades in all aspects, except for esthetics, which did not statistically differ from the others. Significant positive correlations were observed between changes in speech and discomfort on all appliances. Occlusal interference in TTR was very positively correlated to other perceptions, such as changes in speech and discomfort. Speech changes, evaluated by Perceptual Auditory Analysis, increased immediately after conventional wraparound and TTR installation, and reduced after 3 weeks of use, but not back to normal levels observed without device. However, this increase was statistically significant only for the conventional wrap-around and TTR, remaining significant high after 3 weeks. Formant frequencies of vowels were altered at initial time and the changes remained present in conventional, horseshoe-shaped and TTR appliances after 3 weeks. Conclusions: TTR was more harmful to speech than the wrap-around appliances. Among these, conventional and horseshoe-shaped has interfered less in speech. The 3-week period with retainers was not fully sufficient for speech adaptation. TTR was worse classified than the wrap-around retainers in all evaluated perceptions, except in esthetics, which did not differ significantly. Occlusal coverage of TTR seems to be the cause of its rejection and its major changes to speech. Upper arch dimensions little influence volunteers perceptions. Considering speech changes and volunteers perceptions, the wrap-around retainers had better performance and should be the first choice when retainer option is a removable device in the upper arch

Changes consequent to maxillary molar distalization with the bone-anchored pendulum appliance

Objectives: This retrospective study aimed to evaluate the dentoalveolar, skeletal, and soft tissue effects obtained with bone-anchored pendulum appliance in patients with Class II malocclusion. Materials And Methods: A total of 18 patients (4 male, 14 female) at a mean pretreatment age of 14.0 years (+1.08) were enrolled in this study. All patients were treated with the bone-anchored pendulum appliance for an average duration of 4.8 months. Only the active distalization period was evaluated with predistalization and postdistalization lateral cephalograms. Skeletal, dentoalveolar, and soft tissue variables were obtained. Based on these variables, the treatment effects were evaluated with dependent t-test. Results: Correction of Class II molar relationship resulted from distal movement of 3.45 mm and tipping of 11.24° of the first maxillary molars. The premolars were distalized accompanying the molars. Conclusions: The bone-anchored pendulum appliance proved to be an effective method for distalization of maxillary molars in cases that require maximum anchorage, avoiding reciprocal mesial movement of premolars and incisors

Nonsurgical treatment and stability of an adult with a severe anterior open-bite malocclusion

OBJECTIVES: A skeletal anterior open-bite is a challenging malocclusion for the orthodontist due to the difficulty and instability of correction. Treatment options for the adult patient include extractions, anterior extrusion with intermaxillary elastics, posterior intrusion using skeletal anchorage, occlusal adjustment, and orthognathic surgery. Patient compliance plays a key role in posttreatment stability. The present case report demonstrates the orthodontic treatment of an adult patient who presented with a complex open-bite malocclusion. MATERIALS AND METHODS: Treatment involved the placement of four miniscrews to assist intrusion of maxillary molars by applying posterior vertical maxillary elastics and extrusion of the anterior segments using anterior vertical interarch elastics. RESULTS: Ideal intercuspation was successfully achieved and good stability was maintained during 3 years following treatment. CONCLUSION: The intrusion of the maxillary molars with miniscrews is an interesting option in selected cases of skeletal anterior open bite. The retention protocol should be specific in these cases

Facial Profile Evaluation of Isolated Pierre Robin Sequence

Objective: To evaluate numerically the facial profile of children with isolated Pierre Robin sequence (PRS) and to compare them with a control group that has no pathologies and exhibits regular and balanced facial growth, with no skeletal alterations. Patients: Eighty-three children aged 5 to 10 years (PRS group, n = 60; control group, n = 23) were selected. Setting: Hospital for Rehabilitation of Craniofacial Anomalies, University of Sao Paulo (HRAC-USP). Children from the control group were taken from the program of Interceptive Orthodontics at HRAC-USP. Design: Angular and ratio analyses of the facial profiles in both groups were realized through digital photographs. The PRS group was subdivided into two groups-complete and incomplete-according to the sagittal extension of the cleft palate, to investigate the possible influence of cleft extension on the face. Results: The facial convexity angle and the facial inferior third angle were considerably higher in the PRS groups than in the control group and were not significantly different between PRS groups. Nasolabial angle did not differ between groups. Conclusion: The facial profile was more convex in individuals with PRS than in those with regular facial growth and with no pathology. The mandible was responsible for the convexity of the profile in PRS because of its lack off anterior projection. An important relationship between the extension of the cleft palate and alterations in facial profile in PRS was not observed

Subjective facial analysis and its correlation with dental relationships

ABSTRACT INTRODUCTION: Subjective facial analysis is a diagnostic method that provides morphological analysis of the face. Thus, the aim of the present study was to compare the facial and dental diagnoses and investigate their relationship. METHODS: This sample consisted of 151 children (7 to 13 years old), without previous orthodontic treatment, analyzed by an orthodontist. Standardized extraoral and intraoral photographs were taken for the subjective facial classification according to Facial Pattern classification and occlusal analyses. It has been researched the occurrence of different Facial Patterns, the relationship between Facial Pattern classification in frontal and profile views, the relationship between Facial Patterns and Angle classification, and between anterior open bite and Long Face Pattern. RESULTS: Facial Pattern I was verified in 64.24% of the children, Pattern II in 21.29%, Pattern III in 6.62%, Long Face Pattern in 5.96% and Short Face Pattern in 1.99%. A substantial strength of agreement of approximately 84% between frontal and profile classification of Facial Pattern was observed (Kappa = 0.69). Agreement between the Angle classification and the Facial Pattern was seen in approximately 63% of the cases (Kappa = 0.27). Long Face Pattern did not present more open bite prevalence. CONCLUSION: Facial Patterns I and II were the most prevalent in children and the less prevalent was the Short Face Pattern. A significant concordance was observed between profile and frontal subjective facial analysis. There was slight concordance between the Facial Pattern and the sagittal dental relationships. The anterior open bite (AOB) was not significantly prevalent in any Facial Pattern

Cytogenetic biomonitoring in children submitting to a complete set of radiographs for orthodontic planning

Objectives: To evaluate the DNA damage (micronucleus) and cellular death (pyknosis, karyolysis, and karyorrhexis) in exfoliated buccal mucosa cells from children undergoing orthodontic radiographs.Materials and Methods: A total of 25 healthy children undergoing orthodontic therapy partook in a complete set of orthodontic radiographs (lateral cephalographic, posteroanterior cephalographic, panoramic, full periapical exam, and bitewing). the micronucleus test in the buccal exfoliated cells was applied. the paired-samples t-test and the Wilcoxon test were used to compare the frequencies of alterations before and after X-ray exposure.Results: We found no statistically significant differences (P > .05) between micronucleated buccal mucosa cells before and after exposure to radiation. However, radiation did cause other nuclear alterations closely related to cytotoxicity (P = .007).Conclusion: According to the micronucleus test, the complete set of radiographs requested in the orthodontic planning may not be a factor that induces chromosomal damage, but it is able to promote cytotoxicity. (Angle Orthod. 2012;82:585-590.)Univ Fed Rio de Janeiro, Dept Orthodont, Ilha Fundao Rio de Janeiro RJ, BR-21941617 Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Hlth Sci, Santos, BrazilUniversidade Federal de São Paulo, Dept Pathol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Hlth Sci, Santos, BrazilWeb of Scienc