External root resorption with the self-ligating Damon system-a retrospective study.

BACKGROUND: The aim of this study was to compare the degree of external apical root resorption (EARR) in patients treated with self-ligating Damon appliances and with conventional preadjusted appliances. METHODS: The sample comprised 52 patients, divided into two groups. Group 1 consisted of 25 patients treated with self-ligating Damon appliances, with an initial age of 16.04 years, final age of 18.06 years, and treatment time of 2.02 years. Group 2 consisted of 27 patients, treated with conventional preadjusted appliances, with an initial age of 16.77 years, final age of 18.47 years and treatment time of 1.70 years. The groups were matched regarding the initial and final ages, treatment time, type of malocclusion, and treatment protocol without extractions. Root resorption was evaluated on periapical radiographs of the maxillary and mandibular incisors at the end of orthodontic treatment with the scores of Levander and Malmgren. Intergroup comparisons of root resorption were performed with Mann-Whitney tests. RESULTS: No significant difference in the degree of root resorption between the two groups was found. CONCLUSIONS: Similar degrees of resorption can be expected after non-extraction treatment with Damon self-ligating or conventional preadjusted appliances.

Stability of molar relationship after non-extraction Class II malocclusion treatment.

OBJECTIVE: This study aimed to evaluate the stability of molar relationship after non-extraction treatment of Class II malocclusion. METHODS: The sample comprised 39 subjects (16 females, 23 males) with initial Class II malocclusion treated with no extractions, using fixed appliances. Mean age at the beginning of treatment was 12.94 years, at the end of treatment was 15.14 years and at post-retention stage was 21.18 years. Mean treatment time was 2.19 years and mean time of post-treatment evaluation was 6.12 years. To verify the influence of the severity of initial Class II molar relationship in stability of molar relationship, the sample was divided into two groups, one presenting a ½-cusp or ¾-cusp Class II molar relationship, and the other with full-cusp Class II molar relationship. In dental casts from initial, final and post-retention stages, molar, first and second premolars and canine relationships were measured. Data obtained were analyzed by dependent ANOVA, Tukey and Pearson's correlation tests, as well as independent t test between the two groups divided by severity of initial molar relationship. RESULTS: There was a non-statistically significant 0.12-mm relapse of molar relationship. The initial severity of Class II molar relationship was not correlated to relapse in the post-retention period. When compared, the two groups showed no difference in relapse of molar relationship. CONCLUSIONS: It was concluded that correction of Class II molar relationship is stable and initial severity does not influence relapse of molar relationship.

Strategic maxillary second-molar extraction in Class II malocclusion.

Maxillary second-molar extraction in Class II malocclusion is a controversial issue in orthodontics. This treatment protocol is rigorous and not routine. In this case report, we present the orthodontic treatment of a patient with a Class II malocclusion, maxillary crowding, and no mandibular first molars, treated with extraction of the maxillary second molars. The mechanotherapy and indications of maxillary second-molar extraction are discussed.