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

SKELETAL AND DENTAL CHANGES INDUCED BY BIONATOR IN EARLY TREATMENT OF CLASS II

The purpose was to investigate the amount of skeletal and dentoalveolar changes after early treatment of Class II, Division 1 malocclusion with bionator appliance in prepubertal growing patients. Forty Class II patients (19 male and 21 female) were divided in two groups. Treated group consisted of 20 subjects (10 male and 10 female) treated consecutively with bionator. Mean age at the start of treatment (T0) was 9.1 years, while it was 10.6 years at the end of treatment (T1). Mean treatment time was 17.7 months. Pretreatment and post-treatment cephalometric records of treated group were evaluated and compared with a control group consisted of 20 patients (09 male and 11 female) with untreated Class II malocclusion. Intergroup comparisons were performed using Student’s t-tests and chi-square test with Yates’ correction at a significance level of 5 per cent. Bionator appliance was effective in generating differential growth between the jaws. Cephalometric skeletal measurements ANB, WITS, LAFH, Co-A and dental L6-Mp, U1.Pp, IsIi, OB, OJ showed statistically significantly different from the control. The bionator induced more dentoalveolar changes than skeletal during treatment in prepurbetal stage

Changes in alveolar bone support induced by the Herbst appliance: a tomographic evaluation

ABSTRACT Objective: This study evaluated alveolar bone loss around mandibular incisors, induced by the Herbst appliance. Methods: The sample consisted of 23 patients (11 men, 12 women; mean age of 15.76 ± 1.75 years), Class II, Division 1 malocclusion, treated with the Herbst appliance. CBCT scans were obtained before treatment (T0) and after Herbst treatment (T1). Vertical alveolar bone level and alveolar bone thickness of mandibular incisors were assessed. Buccal (B), lingual (L) and total (T) bone thicknesses were assessed at crestal (1), midroot (2) and apical (3) levels of mandibular incisors. Student's t-test and Wilcoxon t-test were used to compare dependent samples in parametric and nonparametric cases, respectively. Pearson's and Spearman's rank correlation analyses were performed to determine the relationship of changes in alveolar bone thickness. Results were considered at a significance level of 5%. Results: Mandibular incisors showed no statistical significance for vertical alveolar bone level. Alveolar bone thickness of mandibular incisors significantly reduced after treatment at B1, B2, B3, T1 and significantly increased at L2. The magnitude of the statistically significant changes was less than 0.2 mm. The changes in alveolar bone thickness showed no statistical significance with incisor inclination degree. Conclusions: CBCT scans showed an association between the Herbst appliance and alveolar bone loss on the buccal surface of mandibular incisors; however, without clinical significance

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

Longitudinal study of mandibular behavior in Class I subjects with vertical and horizontal growth

OBJETIVO: avaliar as possíveis diferenças no comportamento mandibular em indivíduos Classe I com crescimento vertical e horizontal. MÉTODOS: a amostra desse estudo consistiu de 20 indivíduos Classe I não tratados, sendo o grupo 1 composto por 10 indivíduos com padrão de crescimento vertical e o grupo 2 por 10 indivíduos com padrão de crescimento horizontal, pertencentes aos arquivos do Burlington Growth Center, University of Toronto, no Canadá, acompanhados radiograficamente nas idade de 9, 12 e 21 anos. Determinou-se, por meio de telerradiografias cefalométricas, em norma lateral, os valores médios para a avaliação longitudinal do comportamento da mandíbula utilizando as medidas SNB, Co-Gn, SN.GoMe, altura facial anterior e altura facial posterior. RESULTADOS: o valor de SNB e Co-Gn foram maiores no grupo com crescimento horizontal em todas as idades. A medida Sn.GoMe foi significativamente menor no grupo com crescimento horizontal, a altura facial anterior (AFH) apresentou valores menores nos indivíduos com padrão de crescimento horizontal, e a altura facial posterior (PFH) apresentou valores menores nos indivíduos com crescimento vertical. CONCLUSÃO: as comparações longitudinais das tendências de crescimento de indivíduos Classe I indicam que existe diferenças significativas entre os dois grupos. A mandíbula apresentou tendência à rotação horária no grupo 1. O grupo 2 exibiu tendência à característica de indivíduos braquicefálicos, na forma facial, devido ao déficit no desenvolvimento vertical na altura facial anterior.OBJECTIVE: To evaluate possible differences in mandibular behavior in Class I individuals with vertical and horizontal growth patterns. METHODS: The sample consisted of 20 untreated Class I individuals divided into: Group 1 comprising 10 individuals with vertical growth pattern and Group 2 comprising 10 individuals with horizontal growth pattern, all of them belonging to the Burlington Growth Center files, University of Toronto-Canada, radiographically followed-up at ages 9, 12 and 21. Cephalometric radiographs, determined mean values for a long-term evaluation of mandibular behavior using the following measurements: SNB, Co-GN, SN.GoMe, anterior facial height and posterior facial height. RESULTS: SNB and Co-Gn values were higher in horizontal growth group at all of the ages studied; SN.GoMe measure was significantly lower in horizontal growth group; anterior facial height (AFH) showed lower values in individuals with horizontal growth pattern; and posterior facial height (PFH) showed lower values in individuals with vertical growth pattern. CONCLUSION: Long-term comparisons of Class I individuals' growth tendencies indicate that there are significant differences between both groups. Mandible showed a trend to clockwise rotation in Group 1. Group 2 showed a trend to brachycephalic facial form, due to the deficit in vertical development with regard to anterior facial height

Changes in the inclination of lower incisors and the occurrence of gingival recession

Objetivos: o objetivo deste estudo foi investigar se alteracoes na posicao vestibulolingual dos incisivos inferiores em adolescentes podem predispor ao desenvolvimento de recessoes gengivais. Metodos: documentacoes de 189 adolescentes leucodermas (107 meninos e 81 meninas) pre e pos-tratamento ortodontico foram selecionadas. Os pacientes apresentavam uma idade media de 11,2 } 1,9 anos nos exames iniciais e 14,7 } 1,8 anos nos exames finais. A presenca de recessao gengival foi avaliada em modelos de estudo e em fotografias. A inclinacao dos incisivos inferiores, em relacao ao plano mandibular (IMPA) foi medida nos cefalogramas laterais pre e pos-tratamento e os casos foram divididos em proclinados, retroinclinados e inalterados. Resultados: nao foi observada associacao significativa entre a alteracao da inclinacao dentaria e a presenca de recessoes gengivais, utilizando o teste do qui-quadrado (p = 0,277). Foi observado que 107 pacientes (56,6%) apresentaram os incisivos proclinados; 64 pacientes (33,9%) com incisivos retroinclinados; e 18 pacientes (9,5%) nao apresentaram alteracao na inclinacao. Nos casos em que novas recessoes gengivais ocorreram, 64,9% foram vestibularizados, 26,3% foram lingualizados e 8,8% nao apresentaram alteracao na inclinacao. No grupo de pacientes que apresentou migracao coronal da margem gengival, 60% foram movimentados para lingual, 30% foram vestibularizados e 10% nao alteraram de posicao. Conclusoes: apesar de a porcentagem de casos que foram vestibularizados apresentar um maior numero de novas recessoes, esse nao foi estatisticamente significativo.Aim: The aim of this study is to investigate whether altering the labial-lingual position of the lower incisors in adolescents might predispose to the development of gingival recession. Methods: Records from 189 Caucasian adolescents (107 female and 81 male) pre and post orthodontic treatment were selected. Patients presented mean } SD values of initial records age of 11.2 } 1.9 years and final records age of 14.7 } 1.8 years. The presence of gingival recession was evaluated in models and photographs. The inclination of lower incisors to the mandibular plane angle (IMPA) was measured on lateral cephalograms, pre and post-treatment. Cases were divided in: proclined, retroclined and unaltered. No significant association was observed between the alteration of tooth inclination and the presence of gingival recessions, based on chi square analysis (p = 0,277). Results: Data demonstrated that in 107 patients (56.6%) incisors were proclined, in 64 patients (33.9%) incisors were retroinclined and 18 patients (9.5%) did not shown alteration in tooth inclination. In the cases where new gingival recessions occurred, 64.9% had been moved buccally, 26.3% had been moved lingually and 8.8% did not changed inclination. In the group of patients that displayed coronal migration of the gingival margin, 60% had been moved lingually, 30% had been moved buccally and 10% did not changed inclination. Conclusion: Even though the percentage of cases where teeth were proclined showed a larger number of new gingival recessions, it was not statistically significant

TRATAMIENTO DE MALOCLUSIÓN CLASE II DIVISIÓN 1 CON EL APARATO DE HERBST TIPO FÉRULA, DESPUÉS DEL PICO DE CRECIMIENTO PUBERAL

La maloclusión clase II-1, es representada por una alta prevalencia en Brasil, siendo su presencia rutinaria en el consultorio ortodóntico. Una de las principales características de esta maloclusión es la retrusión mandibular, por lo que innumerables aparatos de avance mandibular son presentados en la literatura, siendo uno de ellos el aparato de Herbst; el cual es un aparato funcional fijo idealizado por Emil Herbst (1905) y actualizado por Hans Pancherz en la década del 80. Este aparato se caracteriza por: mantener el avance mandibular de manera continua, y presentar un tiempo menor de tratamiento activo, lo que propicia un impacto estético inmediato, además de no precisar la colaboración del paciente. Con el objetivo de mejorar el anclaje y evitar la rotura de este aparato, se creó la última versión modificada por el Dr Raveli; citado como aparato de Herbst tipo férula metálica. Recientes investigaciones indican el uso de este aparato después del pico de crecimiento puberal, creando una adecuada respuesta condilar. El objetivo de este trabajo es mostrar al ortodoncista una opción de cómo utilizar el aparato de Herbst en maloclusiones clase II-1. Abstract Malocclusion class II-1, is represented by a high prevalence in Brazil, being something common in orthodontic practice. One of the main characteristics of this malocclusion is jaw retrusion , By what many devices of jaw advance are presented in the literature. Being one of them Herbst's device, which is a functional and fixed device created by Emil Herbst (1905) and updated by Hans Pancherz in the decade of 80s.This device is characterized by keeping the jaw advance in a continuous way, while presenting a less active treatment, leading to an immediate aesthetic impact, and the patient cooperation is not required. To improve the anchoring and prevent the collapse of the apparatus was set up last amended version of it by Dr Raveli quoted as Herbst splint. Recent research indicates the use of this device after the peak pubertal growth, creating an appropriate response condylar. The aim of this work is to show the orthodontist a choice of how to use the splint Herbst in Class malocclusions II-