[Is retention justified after interceptive treatment of Class II malocclusion?]

Indication of intermediate retention after early treatment of class II malocclusion has not been yet assessed by comparative studies. Therefore, it is up to the practitioner to analyse the need for retention in the time period between the two phases. Does wearing a retainer indeed decrease the chance of relapse between phase one and phase two? We performed a retrospective comparative study consisting of 90 subjects in mixed dentition with class II molar relationships with an increased overjet (> or = 5 mm) treated in the J.-J. Aknin office with DAC appliance. The sample was divided into two groups: 31 patients wearing retention represented by a removable Hawley plate and 59 children in supervision without retention. Three lateral head-films were made at the beginning and the end of early treatment and before the resumption of the second phase treatment. Studied cephalometrics parameters were assessed according to superimposing Pancherz's analysis. A statistical analysis was performed. Results showed a significantly lower relapse of incisor's protrusion in the group wearing an upper retainer. Results' interpretation was in accordance with the assessment of confusion's factors and selection's criteria. Besides, this study was carried out in intention-to-treat and retention's effectiveness in proportion with patient's compliance. Nevertheless, the study was performed in real conditions. In conclusion, and without randomised trial, results show that retention seems to decrease maxillary incisor movements. It is therefore justified in cases presenting with important class II especially with procumbent incisors.