Ricardo César Gobbi De Oliveira

Overjet, overbite, and anterior crowding relapses in extraction and nonextraction patients, and their correlations.

INTRODUCTION In this study, we aimed to compare the relapse of maxillary and mandibular anterior crowding, overjet, and overbite 5 years after treatment in subjects with Class I and Class II malocclusions treated with and without extractions, and also to evaluate the correlations among these factors. METHODS The sample comprised 84 subjects with Class I and Class II malocclusions, treated with and without extractions. Group 1 comprised 44 subjects with an initial mean age of 12.96 years treated without extractions. Group 2 included 40 subjects with an initial mean age of 13.01 years treated with 4 premolar extractions. Data were obtained from dental casts at the pretreatment, posttreatment, and long-term posttreatment stages. Intergroup comparisons were performed with t tests. To verify the correlations among the relapse of overjet, overbite, and anterior crowding, the Pearson correlation test was used. RESULTS Maxillary incisor irregularity and its relapse in the nonextraction group were significantly greater at the long-term posttreatment stage and the long-term posttreatment period, respectively. Long-term postreatment overjet changes were similar in the groups. Overbite and its relapse were significantly greater in the extraction group in the long-term posttreatment stage and period, respectively. There was a positive correlation of the relapse of mandibular incisor crowding with the relapse of overjet and overbite, and also a correlation of overjet and overbite relapses. CONCLUSIONS There was greater maxillary crowding relapse in the nonextraction group and greater overbite relapse in the extraction group. There were significant and positive correlations of overjet and overbite relapses with mandibular anterior crowding relapse and consequently between overjet and overbite relapses.

Factors Associated to Apical Root Resorption after Orthodontic Treatment

Objective: The aim of this study was to assess the possible factors associated to root resorption, common to daily clinical orthodontics, especially parafunctional habits. Methods: A retrospective study of 600 patients (308 females and 292 males) previously treated orthodontically was conducted. The sample was divided into two groups related to the degree of root resorption at the ending of treatment according to Malmgren. Group 1 comprised 507 patients with a mean initial age of 14.21 years and who had absent or mild final external root resorption, characterized by grades 0, 1 and 2 of root resorption; Group 2 comprised 93 patients with initial mean age of 14.57 years and who had moderate or severe root resorption, characterized by grade 3 and 4. The groups were then compared in terms of age at the beginning and ending of the treatment, treatment time, gender, type of treatment (with and without extractions), parafunctional habits (bruxism, onychophagia, the habit of biting objects, tongue thrusting habit and thumb sucking habit), allergies and pretreatment root resorption. Results: The results show that the initial age, gender, type of malocclusion, parafunctional habits and allergies do not represent a statistically significant risk of root resorption. Conclusion: Treatment time and type (with and without extractions) and the presence of external root resorption at the beginning of the treatment showed significant differences.