ABSTRACT
Objective This study evaluated the frequency of root resorption during the orthodontic treatment with Herbst appliance by Cone Beam Computed Tomography (CBCT).Material and Methods The sample comprised 23 patients (11 men, 12 women; mean ages 15.76±1.75 years) with Class II division 1 malocclusion, treated with Herbst appliance. CBCT was obtained before treatment (T0) and after Herbst treatment (T1). All the dental roots, except third molars, were evaluated, and apical root resorption was determined using the axial guided navigation method. Paired t-tests and Wilcoxon T Test were used to compare the dependent samples in parametric and nonparametric cases, respectively. Chi-Square Test with Yates’ correction was used to evaluate the relationship between apical root resorption and gender. Results were considered at a significance level of 5%.Results Apical resorption was detected by CBCT in 57.96% of 980 roots that underwent Herbst appliance treatment. All patients had minimal resorption and there was no statistical significance between the genders.Conclusion CBCT three-dimensional evaluation showed association between Herbst appliance and minimal apical root resorption, mostly in the anchoring teeth, without clinical significance.
Subject(s)
Humans , Male , Female , Adolescent , Cone-Beam Computed Tomography/methods , Orthodontic Appliances, Functional/adverse effects , Root Resorption , Tooth Apex , Imaging, Three-Dimensional , Observer Variation , Odontometry , Radiographic Image Interpretation, Computer-Assisted , Retrospective Studies , Root Resorption/etiology , Sex Factors , Statistics, Nonparametric , Tooth Movement Techniques/adverse effectsABSTRACT
Este estudo prospectivo teve como objetivo avaliar tridimensionalmente a rotação e deslocamento dos primeiros molares permanentes induzidos pelo uso do aparelho Herbst bandado em pacientes com Classe II divisão 1, tratados após o surto de crescimento pubertário. A amostra constituída por 24 pacientes leucodermas , 10 do gênero feminino e 14 do gênero masculino, com idade cronológica média de 16 anos e 1 mês. Os pacientes foram tratados com aparelho de Herbst bandado por um período de 8 meses. Para a avaliação inicial e final, foram utilizadas tomografias computadorizadas de feixe cônico (TCFC) realizadas antes da colocação do aparelho e após a remoção do mesmo. A obtenção das tomografias foi feita com tomógrafo i-CAT Classic e os dados foram exportados no formato DICOM (Digital Image and Comunication in Medicine) e avaliados no programa Dolphin® Imaging 11.5 Premium (Dolphin Imaging & Management Solutions, Petterson Technology, Chatsworth, CA, EUA). Foram analisadas dezessete medidas lineares avaliadas nos cortes multiplanares, nos planos: coronal, sagital e axial, duas vezes por um observador previamente calibrado. Os dados obtidos foram calculados por um programa de software desenvolvido para esta pesquisa, através do sistema de coordenadas cartesianas tridimensional. Tal sistema é constituído por três retas mutuamente perpendiculares, nos três planos do espaço, representados pelos eixos X, Y e Z e que se interceptam num ponto com ângulos retos entre si, chamado de Origem, que nesta pesquisa é o Ponto Zero. Qualquer aplicação em que seja necessário saber a localização e orientação de corpos no espaço utiliza-se o conceito de sistema de coordenadas. A análise estatística foi realizada por meio do teste t de Student, com nível de significância de 5%. Esta pesquisa, relativa ao uso do aparelho de Herbst bandado, permitiu a constatação dos seguintes fatos: correção da má oclusão de Classe II, divisão 1; intensificação dos movimentos dentários de rotação e o deslocamento nos molares inferiores, em relação aos superiores; distalização dos molares superiores, por deslocamento e rotação, e discreta expansão; mesialização dos molares inferiores, por deslocamento e rotação, e discreta expansão; e perda de ancoragem, motivada pela mesialização dos dentes inferiores, com movimentação duas vezes maior que a esquelética
This prospective study aimed to evaluate three-dimensionally the rotation and displacement of first permanent teeth produced by Herbst appliance in Class II divison 1 patients after puberal growth spurt. The sample consisted of 24 Caucasian patients, 10 females and 14 males, with mean age of 16.1 years old. The patients, were treated for period of 8 months with Herbst appliance. Cone beam computed tomography (CBCT) was performed before and after the removal of the Herbst appliance for initial and final evaluations, respectively. The images were obtained with classic i-CAT tomography and the data were exported by using the DICOM software (Digital Image and Comunication in Medicine) and evaluated with the Dolphin® Imaging 11.5 Premium software (Dolphin Imaging & Management Solutions, Petterson Technology, Chatsworth, CA, USA). Seventeen linear measurements regarding multiplanar sections were analyzed according to the following planes: coronal, sagittal and axial, twice by a previously calibrated observer. Data were calculated by using a software program developed by this present study based on three-dimensional cartesian coordinates. This system consists of three straight lines in three spatial planes, represented by X, Y and Z axes, intercepting at a point with right angles denominated Origin Point and described as Zero Point in this study. The concept of coordinate system is used in any application which it is necessary know the location and orientation of points in space. Statistical analysis was performed by means of Student t test with 5% significance level. This study, related to the use of the Herbst appliance, contributed to state the following facts: correction the Class II division 1 malocclusion; intensification of rotational dental movement and the displacement in the lower molars by displacement and rotation, and discrete expansion; and anchorage loss due to mesial movement of lower teeth, twice greater than bone displacement
Subject(s)
Humans , Male , Female , Adolescent , Analysis of Variance , Molar , Orthotic Devices , Imaging, Three-Dimensional , Malocclusion, Angle Class II , Cone-Beam Computed TomographyABSTRACT
O aparelho de Herbst é um dos aparelhos mais usado na atualidade para correçãoda Classe II divisão 1 com retrusão mandibular. Quando utilizado no surto, ou logoapós o surto de crescimento, pode ocorrer algum ganho esquelético, favorável à correçãoda discrepância anteroposterior de forma efetiva e com resultados estáveis. O presenteartigo teve como objetivo relatar um caso clínico de uma paciente portadora de má-oclusãode Classe II divisão 1 com retrusão mandibular, associada à protrusão maxilar, tratada emduas fases: com o aparelho de Herbst splint metálico seguido de tratamento ortodônticocom aparelho lixo.
The Herbst appliance is currently one of the most used appliances for thecorrection of Class II division 1 with mandibular retrusion. When used in peak, ot just afterthe peak of growth it can result in some skeletal gain, which is favorable to the correction ofanteroposterior discrepancy with effective and stable results. This article aims to report acase of a patient with malocclusion Class II division 1 with mandibular retrusion, associatedwith maxillary protusion, treated in two stages: with Herbst splint metallic appliance followedby fixed appliance orthodontic treatment.