RESUMO
OBJECTIVES: The aim of this study was to evaluate the reliability of 3-dimensional maxillary dental changes using two methods of digital model superimposition. SETTING AND SAMPLE POPULATION: The Department of Orthodontics of Bauru Dental School, University of São Paulo and University of Michigan Craniofacial Growth Center. Fifteen subjects with normal occlusion. MATERIAL & METHODS: The sample was composed of digital study models of 15 normal occlusion subjects taken at 13 (T1), 18 (T2) and 60 years of age (T3). Using the software SlicerCMF 3.1, superimposition (registration) was conducted using 9 landmarks placed on the incisive papilla, second and third palatal rugae and 10 mm distal to the third palatal rugae. Two registration methods were compared: landmarks (LA) and regions of interest (ROI). Three-dimensional changes of landmarks on the buccal cusp tip of posterior teeth bilaterally and the incisal edge of the right central incisor were measured by three examiners. Intraclass correlation coefficients and Bland-Altman method evaluated intra- and inter-examiner agreements. RESULTS: Good or excellent intra-examiner agreement was found for T1-T2 and T2-T3 measurements using both registration methods. Inter-examiner agreements were good to excellent for T1-T2 measurements and poor to fair for most T2-T3 measurements. Mean T1-T2 differences were less than 0.5 mm for most measurements. CONCLUSION: Maxillary digital dental models of patients with normal occlusion superimposed on palatal rugae showed an adequate reliability for a 5-year interval comparison using landmarks or regions of interest. Lower than acceptable reproducibility using both superimposition methods was found for a 40-year interval comparison.
Assuntos
Envelhecimento , Maxila , Humanos , Pessoa de Meia-Idade , Modelos Dentários , Palato , Reprodutibilidade dos TestesRESUMO
INTRODUCTION: With the advent of cone beam computed tomography (CBCT), it is now possible to quantitatively evaluate the effects of rapid maxillary expansion (RME) on the entire maxillary complex in growing patients. OBJECTIVE: The purpose of this study is to use three-dimensional images to evaluate the displacement that occurs at the circummaxillary sutures (frontonasal, zygomaticomaxillary, intermaxillary, midpalatal, and transpalatal sutures) following rapid maxillary expansion in growing children. METHODS: The CBCT scans of 25 consecutively treated RME patients (10 male, 15 female) with mean age of 12.3±2.6 years, were examined before expansion and immediately following the last activation of the expansion appliance. RESULTS: Statistically significant (P<0.05) amounts of separation were found for the displacement of the bones of the frontonasal suture, the intermaxillary suture, the zygomaticomaxillary sutures, and the midpalatal suture. The change in angulation of the maxillary first molars due to RME was also statistically significant. There was no statistically significant displacement of the transpalatal suture. CONCLUSIONS: Rapid maxillary expansion results in significant displacement of the bones of circummaxillary sutures in growing children.
Assuntos
Tomografia Computadorizada de Feixe Cônico/métodos , Maxila/diagnóstico por imagem , Técnica de Expansão Palatina , Pontos de Referência Anatômicos/diagnóstico por imagem , Cefalometria/métodos , Criança , Suturas Cranianas/diagnóstico por imagem , Feminino , Seguimentos , Osso Frontal/diagnóstico por imagem , Humanos , Imageamento Tridimensional/métodos , Masculino , Desenvolvimento Maxilofacial , Dente Molar/diagnóstico por imagem , Osso Nasal/diagnóstico por imagem , Desenho de Aparelho Ortodôntico , Técnica de Expansão Palatina/instrumentação , Palato/diagnóstico por imagem , Estudos Retrospectivos , Zigoma/diagnóstico por imagemRESUMO
INTRODUCTION: With the advent of cone beam computed tomography (CBCT), it is now possible to quantitatively evaluate the effects of rapid maxillary expansion (RME) on the entire maxillary complex in growing patients. OBJECTIVE: The purpose of this study is to use three-dimensional images to evaluate the displacement that occurs at the circummaxillary sutures (frontonasal, zygomaticomaxillary, intermaxillary, midpalatal, and transpalatal sutures) following rapid maxillary expansion in growing children. METHODS: The CBCT scans of 25 consecutively treated RME patients (10 male, 15 female) with mean age of 12.3 ± 2.6 years, were examined before expansion and immediately following the last activation of the expansion appliance. RESULTS: Statistically significant (P < 0.05) amounts of separation were found for the displacement of the bones of the frontonasal suture, the intermaxillary suture, the zygomaticomaxillary sutures, and the midpalatal suture. The change in angulation of the maxillary first molars due to RME was also statistically significant. There was no statistically significant displacement of the transpalatal suture. CONCLUSIONS: Rapid maxillary expansion results in significant displacement of the bones of circummaxillary sutures in growing children. .
INTRODUÇÃO: com o advento da tomografia computadorizada de feixe cônico (TCFC), hoje é possível avaliar quantitativamente os efeitos da expansão rápida da maxila (ERM) em todo o complexo maxilar em pacientes em crescimento. OBJETIVO: este estudo usou imagens tridimensionais para avaliar o deslocamento das suturas circum-maxilares (frontonasal, intermaxilar, palatina mediana e palatina transversa) após a expansão rápida da maxila em crianças em crescimento. MÉTODOS: imagens de TCFC de 25 pacientes tratados consecutivamente com ERM (10 meninos, 15 meninas) com idade média de 12,3 ± 2,6 anos foram obtidas e examinadas antes da expansão e imediatamente após a última ativação do aparelho expansor. RESULTADOS: houve deslocamento estatisticamente significativo (p < 0,05) dos ossos da sutura frontonasal, intermaxilar, zigomaticomaxilar e palatina mediana. A alteração na angulação dos primeiros molares superiores devido à ERM também foi estatisticamente significativa. Não houve deslocamento estatisticamente significativo da sutura palatina transversa. CONCLUSÕES: a expansão rápida da maxila resultou em deslocamentos significativos dos ossos das suturas circum-maxilares em crianças em crescimento. .
Assuntos
Criança , Feminino , Humanos , Masculino , Tomografia Computadorizada de Feixe Cônico/métodos , Maxila , Técnica de Expansão Palatina , Pontos de Referência Anatômicos , Cefalometria/métodos , Suturas Cranianas , Seguimentos , Osso Frontal , Imageamento Tridimensional/métodos , Desenvolvimento Maxilofacial , Dente Molar , Osso Nasal , Desenho de Aparelho Ortodôntico , Técnica de Expansão Palatina/instrumentação , Palato , Estudos Retrospectivos , ZigomaRESUMO
OBJECTIVE: To evaluate immediate soft tissue changes following rapid maxillary expansion (RME) in growing patients, using cone beam computed tomography (CBCT). METHODS: Twenty-three consecutive patients (10 male, 13 female) treated by RME were selected. Patients were scanned using CBCT prior to placement of the rapid maxillary expander (T0), then immediately following full activation of the appliance (T1). Defined landmarks were then located on the pre- and post-treatment orientated images. Change in landmark position from pre- to post-treatment was then measured. In addition to landmarks, 10 direct measures were made to determine distance change without regard to direction to measure soft tissue change of the lips. RESULTS: Significant transverse expansion was measured on most soft tissue landmark locations. All the measures made showed significant change in the lip position with a lengthening of the vertical dimension of the upper lip, and a generalized decrease of anterior-posterior thickness of both the upper and lower lips. CONCLUSIONS: Significant changes in the soft tissue do occur with RME treatment. There is a transverse widening of the midface, and a thinning of the lips.
OBJETIVO: avaliar as mudanças imediatas no tecido mole após a expansão rápida da maxila (ERM) em pacientes em fase de crescimento, usando tomografia computadorizada de feixe cônico (TCFC). MÉTODOS: vinte e três pacientes (10 do sexo masculino e 13 do feminino) tratados com ERM foram selecionados. Os pacientes foram escaneados por TCFC antes da implantação do expansor maxilar (T0) e imediatamente após a completa ativação do aparelho (T1). Pontos cefalométricos definidos foram localizados nas imagens pré- e pós-tratamento. As mudanças de posição desses pontos do pré- para o pós-tratamento foram, então, analisadas. Adicionalmente aos pontos, 10 medições diretas foram realizadas para determinar a mudança nas distâncias - independentemente da direção - nos tecidos moles dos lábios. RESULTADOS: uma expansão transversal significativa foi notada na maioria dos pontos demarcados em tecido mole. Todas as medições apresentaram mudança significativa na posição labial, com um aumento da dimensão vertical do lábio superior e uma redução generalizada da espessura anteroposterior dos lábios inferior e superior. CONCLUSÃO: de fato, mudanças significativas do tecido mole ocorrem no tratamento com ERM. Há um alargamento transversal do terço médio da face e um afinamento dos lábios.
RESUMO
This study compared the skeletal and dental characteristics of Class II Division 1 white Americans and Mexicans. It was designed specifically to the evaluate ethnic, age, and sex differences of 101 whites and 107 Mexican mestizos, with approximately equal numbers in each subgroup. Three-way analyses of variance were used to simultaneously evaluate the effects of age, sex, ethnicity, and their interactions. Although Mexicans and whites in the United States had similar maxillomandibular relationships, Mexicans showed greater protrusion of the jaws and teeth. Mexican subjects with Class II malocclusions also showed less divergence of the cranial base (SN-FH angle) and greater vertical tendencies (MPA, Y-axis, and palatal plane angle) than their white counterparts. In comparison with children (mean age 9.0 years), young adults (mean age 20.1 years) had significantly larger craniofacial dimensions, jaws that were positioned more forward, and teeth that were more protruded. Sex differences pertained only to size (men were larger) and maxillary incisor angulation (men were more protrusive). The findings pertaining to the ethnic differences have important clinical implications regarding treatment decisions for Mexican and white patients. In addition, this study provides a foundation for future studies pertaining to Class II malocclusion in Mexicans.