Camila Leite Quaglio

Tooth-wear patterns in adolescents with normal occlusion and Class II Division 2 malocclusion

INTRODUCTION In this study, we investigated tooth-wear patterns in adolescents with either normal occlusion or Class II Division 2 malocclusion. METHODS The sample consisted of dental casts from 165 subjects that were divided into 2 groups: 115 normal occlusion subjects (mean age, 14.3 years) and 50 complete Class II Division 2 subjects (mean age, 13.9 years). Dental wear was assessed by using a modified version of the tooth wear index. The 2 groups were compared with the Mann-Whitney test for the frequency and severity of wear on each surface of each group of teeth. The level of statistical significance was set at 5%. RESULTS The normal occlusion group statistically had greater tooth wear on the incisal surfaces of the maxillary lateral incisors and the incisal surfaces of the maxillary canines than did the Class II Division 2 malocclusion group. The malocclusion group showed statistically greater tooth wear on the labial surfaces of the mandibular lateral incisors, the occlusal surfaces of the maxillary premolars and first molars, the occlusal surfaces of the mandibular premolars, the palatal surfaces of the maxillary second premolars, and the buccal surfaces of the mandibular premolars and first molars than did the normal occlusion group. CONCLUSIONS Subjects with normal occlusion and those with complete Class II Division 2 malocclusions have different tooth-wear patterns. Tooth wear on the malocclusion subjects should not be considered pathologic but, rather, the consequence of different interocclusal arrangements.

Stability and relapse of maxillary anterior crowding treatment in Class I and Class II Division 1 malocclusions

INTRODUCTION The maxillary anterior teeth are the most important to facial esthetics because they are the first to show on a smile. Therefore, stability of the maxillary anterior teeth alignment is an important issue. The objective of this study was to compare the stability of maxillary anterior tooth alignment in Class I and Class II Division 1 malocclusions. METHODS The sample comprised dental casts of 70 patients with Class I and Class II Division 1 malocclusions and a minimum of 3 mm of maxillary anterior crowding measured by an irregularity index. The patients were treated with extractions and evaluated at pretreatment and posttreatment and at least 5 years after treatment. The sample was divided into 3 groups: group 1, Class I malocclusion treated with 4 first premolar extractions comprising 30 subjects, with an initial age of 13.16 years and 8.59 mm of initial maxillary irregularity; group 2, Class II malocclusion treated with 4 first premolar extractions comprising 20 subjects, with an initial age of 12.95 years and 11.10 mm of maxillary irregularity; and group 3, Class II malocclusion treated with 2 first maxillary premolar extractions comprising 20 subjects, with an initial age of 13.09 years and 9.68 mm of maxillary irregularity. RESULTS The decrease in the maxillary irregularity index was significantly greater in group 2 than in group 1 during treatment. The stability of maxillary anterior alignment was 88.12% over the long term; 77% of the linear displacement of the anatomic contact points tended to return to their original positions. CONCLUSIONS Stability of maxillary anterior alignment between the 3 groups was similar. The stability of maxillary anterior alignment was high over the long term, but a high percentage of teeth tended to return to their original positions.

Tooth-wear patterns in subjects with Class II Division 1 malocclusion and normal occlusion.

INTRODUCTION The aim of this study was to investigate the prevalence of tooth wear in adolescents with Class II malocclusion, compared with those with normal occlusion. METHODS The sample consisted of dental casts obtained from 310 subjects, divided into 3 groups: group 1, 110 subjects with normal occlusion (mean age, 13.51 years); group 2, 100 complete Class II Division 1 patients (mean age, 13.44 years); and group 3, 100 half-cusp Class II Division 1 patients (mean age, 13.17 years). Dental wear was assessed by using a modified version of the tooth-wear index. The 3 groups were compared by means of the Kruskal-Wallis and Dunn tests, considering the frequency and the severity of wear on each surface of each group of teeth. The level of statistical significance was set at 5%. RESULTS The normal occlusion group had statistically greater tooth wear on the palatal surfaces of the maxillary central incisors and the incisal surfaces of the maxillary canines than the corresponding surfaces in both Class II malocclusion groups. The complete and half-cusp Class II Division 1 malocclusion groups had statistically greater tooth wear on the occlusal surfaces of the maxillary second premolar and first molar, the occlusal surfaces of the mandibular premolars, and the buccal surfaces of the mandibular posterior teeth compared with the normal occlusion group. The half-cusp Class II Division 1 malocclusion group had significantly greater tooth wear on the incisal surfaces of the mandibular incisors compared with the complete Class II Division 1 malocclusion group. CONCLUSIONS Subjects with normal occlusion and complete or half-cusp Class II Division 1 malocclusions have different tooth-wear patterns. Tooth wear on the malocclusion subjects should not be considered pathologic but rather consequent to the different interocclusal tooth arrangement.

Craniofacial characteristics of Caucasian and Afro-Caucasian Brazilian subjects with normal occlusion

Objective The objective of this study was to compare the skeletal, dental and soft tissue characteristics of Caucasian and Afro-Caucasian Brazilian subjects with normal occlusion and to evaluate sexual dimorphism within the groups. Material and Methods The sample comprised lateral cephalograms of untreated normal occlusion subjects, divided into 2 groups. Group 1 included 40 Caucasian subjects (20 of each sex), with a mean age of 13.02 years; group 2 included 40 Afro-Caucasian subjects (20 of each sex), with a mean age of 13.02 years. Groups 1 and 2 and males and females within each group were compared with t tests. Results Afro-Caucasian subjects presented greater maxillary protrusion, smaller upper anterior face height and lower posterior face height, larger upper posterior face height, greater maxillary and mandibular dentoalveolar protrusion as well as soft tissue protrusion than Caucasian subjects. The Afro-Caucasian female subjects had less mandibular protrusion and smaller total posterior facial height and upper posterior facial height than males. Conclusions Brazilian Afro-Caucasian subjects have greater dentoalveolar and soft tissue protrusion than Brazilian Caucasian subjects, with slight sexual dimorphism in some variables.

Maxillary anterior alignment stability in Class I and Class II malocclusions treated with or without extraction

OBJECTIVE To compare the postretention stability of maxillary incisors alignment in subjects with Class I and II malocclusion treated with or without extractions. MATERIALS AND METHODS The sample comprised 103 subjects with initial maxillary anterior irregularity greater than 3 mm and was divided into four groups: group 1 comprised 19 patients with Class I malocclusion treated with nonextraction (mean initial age = 13.06 years); group 2 comprised 19 patients with Class II malocclusion treated with nonextraction (mean initial age = 12.54 years); group 3 comprised 30 patients with Class I malocclusion treated with extractions (mean initial age = 13.16 years); group 4 comprised 35 patients with Class II malocclusion treated with extractions (mean initial age = 12.99 years). Dental casts were obtained at three different stages: pretreatment (T1), posttreatment (T2), and long-term posttreatment (T3). Maxillary incisor irregularity and arch dimensions were evaluated. Intergroup comparisons were performed by one-way analysis of variance followed by Tukey tests. RESULTS In the long-term posttreatment period, relapse of maxillary crowding and arch dimensions was similar in all groups. CONCLUSION Changes in maxillary anterior alignment in Class I and Class II malocclusions treated with nonextractions and with extractions were similar in the long-term posttreatment period.

Stability of maxillary anterior crowding treatment

OBJETIVO: avaliar a estabilidade e recidiva do tratamento de apinhamento dos dentes anterossuperiores em casos com extracoes de pre-molares e avaliar a tendencia dos dentes apinhados, no inicio do tratamento, a retornar a sua posicao original. METODOS: a amostra consistiu de 70 pacientes de ambos os sexos, com ma oclusao inicial de Classe I e Classe II de Angle, tratados com extracoes dos primeiros pre-molares. A idade media inicial foi de 13,08 anos. Foram avaliados os modelos de estudo nas fases inicial (T1), final (T2) e, em media, 9 anos pos-tratamento (T3) de cada paciente. As variaveis da arcada superior avaliadas e comparadas estatisticamente pela Analise de Variância (ANOVA) foram: indice de irregularidade de Little Superior (IRLS), comprimento da arcada (CAS) e distância intercaninos (DICS). O Teste de Correlacao de Pearson foi utilizado para verificar se alguma variavel estudada teria influencia sobre o apinhamento nas tres fases (IRLS1, IRLS2, IRLS3) e em cada deslocamento de Little (A, B, C, D, E), na fase inicial e pos-tratamento. RESULTADOS: a recidiva do apinhamento superior (IRLS3-2) e influenciada pelo apinhamento inicial (IRLS1), e os dentes tendem a voltar a posicao original. CCONCLUSAO: os resultados ressaltam a atencao que o ortodontista deve dar a recidiva anterossuperior, principalmente aqueles dentes que estavam apinhados antes do tratamento.