Cone beam computed tomography study of apical root resorption induced by Herbst appliance

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

Cone beam computed tomography study of apical root resorption induced by Herbst appliance

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

Avaliação tomográfica tridimensional do tratamento da classe II divisão 1 com aparelho de Herbst

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...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... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Two-Step Extraction of the Lower First Molar for Class III Treatment in Adult Patient

The aim of this article is to describe a case report of Class III malocclusion treatment with lower first molar extraction. The 27-year-old Caucasian male patient presented a symmetric face with a straight profile, hyperdivergent growth pattern, molar and cuspid Class III relation, and an anterior crossbite as well as a mild crowding on cuspids area, in both upper and lower arches and a tendency to posterior crossbite. The treatment was performed by the use of Haas expansion appliance followed by an initial alignment and leveling of the upper and lower arches with a fixed edgewise appliance, extraction of lower teeth aiming the correction of the incisors proclination and end the treatment with a Class I molar relationship. It resulted in a significant change in the patient’s profile, dentoalveolar Class III correction, upper arch expansion, leveling and alignment of the upper and lower arches, and improvement of tipping of the upper and lowers incisors. In cases of a dentoalveolar compensation in well positioned bone bases the treatment with fixed appliances is an alternative and extraction of lower teeth is considered

Influence of the cranial base flexion on Class I, II and III malocclusions: a systematic review

ABSTRACT Objective: The aim of this study was to perform a systematic review on the morphological characteristics of the skull base (flexion, anterior length and posterior length) and the concomitant development of malocclusions, by comparing differences in dimorphism, ethnicity and age. Methods: The articles were selected by means of electronic search on BBO, MEDLINE and LILACS databases from 1966 to 2016. A qualitative evaluation of the methodologies used on the articles was also performed. Results: Although the literature on this topic is abundant, only 16 articles were selected for the present systematic review. The cranial base angle itself does not seem to play a significant role in the development of malocclusions. In fact, the cranial base angle is relatively stable at the ages of 5 to 15 years. Conclusions: A more obtuse angle at the skull base, in association or not with a greater anterior length of the cranial base, can contribute to the development of Class II division 1 malocclusions. On the other hand, a more acute angle at the skull base can contribute to a more anterior positioning of the mandible and to the development of Class III malocclusions