Décio Rodrigues Martins

Effects of intrusion combined with anterior retraction on apical root resorption

This study evaluated the influence of intrusion mechanics combined with anterior retraction on root resorption of the maxillary incisors. A sample of 56 patients was divided into two groups: group 1 comprised 28 patients (12 females and 16 males), presenting with an increased overjet and deep overbite (6.48 and 4.78 mm, respectively) treated with reverse curve of Spee intrusion mechanics and group 2 comprised 28 patients (12 females and 16 males) with an increased overjet of 5.67 mm and a normal overbite of 1.12 mm. The initial mean ages for groups 1 and 2 were 13.41 and 13.27 years, respectively. Pre- (T1) and post- (T2) treatment periapical radiographs were used to evaluate root resorption. The groups were compared using the Mann-Whitney U-test. Correlation between root resorption and tooth movement was investigated with Spearmans correlation coefficient. The subjects in group 1 had statistically greater root resorption (P < 0.05) than those in group 2. The initial overbite severity and the amount of correction had significant positive correlations with root resorption (r = 0.324 and r = 0.320, respectively). The combination of anterior retraction with intrusive mechanics causes more root resorption than anterior retraction of the maxillary incisors alone.

Effects of accentuated and reversed curve of Spee on apical root resorption

INTRODUCTION In this study, we evaluated the influence of intrusion mechanics with accentuated and reversed curve of Spee on root resorption of the maxillary and mandibular incisors. METHODS A sample of 60 patients with Class I and Class II Division 1 malocclusions having nonextraction treatment was divided into 2 groups with the following characteristics: group 1 comprised 30 deepbite patients, treated with accentuated and reversed curve of Spee intrusion mechanics, with an initial mean age of 12.8 +/- 1.23 years (range, 10.01-15.32 years), and group 2 comprised 30 patients with normal overbite treated without intrusion mechanics, with an initial mean age of 12.87 +/- 1.43 years (range, 10.02-15.36 years). Pretreatment and posttreatment periapical radiographs were used to evaluate root resorption. The groups were compared by using the Mann-Whitney U test. Correlation between root resorption and tooth movement was investigated with the Spearman correlation coefficient. RESULTS The deepbite group treated with accentuated and reversed curve of Spee had statistically greater root resorption (1.87) than the normal overbite group (1.54), at P = .017. Changes in overbite and vertical displacements of the maxillary central incisor apices had significant correlations to root resorption (r = 0.30, P = .019; r = 0.27, P = .037, respectively). CONCLUSIONS Accentuating and reversing the curve of Spee in the archwires to correct deep overbite causes more root resorption than nonintrusive mechanics.

Orthognathic treatment for a patient with Class III malocclusion and surgically restricted mandible

This case report describes the orthodontic-surgical treatment of an adult with Down syndrome and a Class III skeletal malocclusion with posterior open bite, horizontal facial pattern, missing mandibular posterior teeth, and surgical restriction of the mandible.

Estudo comparativo das dimensões transversais dos arcos dentários entre jovens com oclusão normal e má oclusão de Classe II, 1ª divisão

OBJETIVO: avaliar as possiveis diferencas nas dimensoes transversais dos arcos dentarios superiores e inferiores entre jovens com oclusao normal e ma oclusao de Classe II, 1a divisao. METODOLOGIA: foram avaliados 170 pares de modelos em gesso de jovens brasileiros leucodermas, com dentadura permanente, sendo 76 com oclusao normal (41 do genero feminino e 35 do masculino) e media de idade de 13 anos e 6 meses e 94 com ma oclusao de Classe II, 1a divisao (58 do genero feminino e 36 do masculino) e media de idade de 13 anos e 9 meses. Este grupo com ma oclusao foi dividido em duas categorias: Classe II sem apinhamento e Classe II com apinhamento. Compararam-se as distâncias intercaninos, interprimeiros pre-molares e intermolares, em ambos os arcos dentarios. RESULTADOS: em relacao ao grupo com oclusao normal, os jovens do genero masculino evidenciaram as seguintes diferencas estatisticamente significantes: 1) distância intercaninos inferiores maior para o grupo com Classe II sem apinhamento; 2) distância interprimeiros pre-molares superiores menor para o grupo com Classe II sem apinhamento e 3) distâncias interprimeiros pre-molares e intermolares, superiores e inferiores, menores para o grupo com Classe II com apinhamento. Por sua vez, o genero feminino evidenciou: 1) distâncias interprimeiros pre-molares e intermolares superiores menores para o grupo com Classe II sem apinhamento e 2) distâncias interprimeiros pre-molares e intermolares, superiores e inferiores, menores para o grupo com Classe II com apinhamento. CONCLUSAO: de um modo geral, os jovens com ma oclusao de Classe II, 1a divisao, apresentaram uma tendencia para deficiencia transversal posterior dos arcos dentarios, principalmente no grupo com apinhamento.

Treatment of a Class II subdivision malocclusion with multiple congenitally missing teeth

This case report describes the treatment of a patient with a Class II Division 1 subdivision right malocclusion with 8 congenitally missing teeth, incompetent lips, and incisor protrusion. The treatment plan included extractions and space closure with retraction of the anterior teeth; symmetric mechanics were used in the mandibular arch and asymmetric mechanics in the maxillary arch. Because of the mechanics used, some midline deviations were expected. Knowledge of diagnosis and treatment planning of asymmetric malocclusions and dental esthetics are essential for success when correcting asymmetic problems, but, even so, small clinical compromises should be expected.

Previsibilidade das medidas ANB e 1-NA da análise cefalométrica de Steiner

The purpose of our study was to verify in the beginning, at the end of treatment, and approximately 5 years posttreatment, the predictability of the estimated values for ANB and 1-NA during treatment planning when using the Steiner analysis. The sample consisted of 149 caucasian patients, descending on spaniards, italians and portuguese, from the Bauru county, with Class I or II malocclusions, who had undergone Edgewise therapy with and without extraction of four premolars. The sample was divided in three groups according to the facial pattern: horizontal (27 patients), balanced (79 patients) and vertical (43 patients), matched by age. According to the methodology used the results showed that there was correlation between the facial pattern and ANB, but no correlation with the behavior of 1-NA; the estimated ANB was statistically different compared to the end of treatment and 5 years posttreatment, except for the vertical group. The estimated values for 1-NA where statistically different compared to the end of treatment and 5 posttreatment in all three groups; the 1-NA value raised significantly with age. The error of the estimated values for ANB and 1-NA are not very relevant clinically, therefore they could still be used as long as they remain as a flexible tool and not a strict parameter.

Maturational changes of the normal occlusion: A 40-year follow-up

Introduction: In this study, we aimed to evaluate the changes in dental arch dimensions, tooth size, and incisor crowding in subjects with normal occlusion over a 40‐year period. Methods: A sample of 82 white subjects with normal occlusion evaluated in adolescence and early adulthood was recruited for a third evaluation in their sixth decade of life. The final sample included dental casts of 22 subjects (12 men, 10 women) obtained at mean ages of 13.3, 17.8, and 60.9 years. The following variables were measured on the digital casts: mesiodistal tooth size; clinical crown height; arch length, width, and perimeter; palatal depth; crowding; overjet; overbite; and curve of Spee. Interphase changes were evaluated using repeated measures analysis of variance, followed by Tukey tests (P <0.05). Results: Increases of clinical crown height in the posterior teeth and incisor crowding were found. Decreases of mesiodistal tooth size, mandibular intercanine width, arch length, arch perimeter, overbite, and curve of Spee were observed. Palatal depth increased from 13 to 17 years of age. No changes were observed for overjet. Conclusions: Subjects with normal occlusion had changes in tooth size and alignment, overbite, and arch dimensions from adolescence to late adulthood. HIGHLIGHTSWe quantitatively assessed the normal occlusion from 13 to 60 years of age.Changes in dental arch dimensions, tooth size, and incisor crowding were assessed.Tooth size and alignment, overbite, and arch dimensions changed from 13 to 60 years of age.