Comparison of AdvanSync and intermaxillary elastics in the correction of Class II malocclusions: A retrospective clinical study.

INTRODUCTION

Our objectives were to compare the skeletal, dentoalveolar, and soft tissue effects of the AdvanSync appliance (Ormco, Glendora, Calif) with intermaxillary elastics in the correction of Class II malocclusions in growing patients.

METHODS

A retrospective study was conducted using lateral cephalograms of patients taken before and after comprehensive orthodontic treatment; 41 patients consecutively treated with the AdvanSync were compared with 41 similar patients treated with intermaxillary Class II elastics. All patients had significant growth potential during treatment, as assessed by cervical vertebral maturation. A comparison group was generated from historical data bases and matched to the experimental groups for skeletal age, sex, and craniofacial morphology. Treatment changes were evaluated between the time points using a custom cephalometric analysis generating 31 variables as well as regional superimpositions. Data were analyzed using 1-way analysis of variance and Tukey-Kramer tests.

RESULTS

The effects of the AdvanSync and fixed orthodontics included maxillary growth restriction, protrusion, proclination, and intrusion of the mandibular incisors as well as mesialization of the mandibular molars (P <0.01). The effects of Class II elastics and fixed orthodontics were similar to AdvanSync, with the exceptions of less maxillary growth restriction and greater retrusion and retroclination of the maxillary incisors (P <0.01). Significant mandibular growth stimulation, relative to the untreated controls, did not occur with either modality.

CONCLUSION

AdvanSync and intermaxillary elastics were effective in normalizing Class II malocclusions during comprehensive fixed orthodontics. AdvanSync produced its effects through maxillary skeletal growth restriction and mandibular dentoalveolar changes. Class II elastics worked primarily through dentoalveolar changes in both the maxilla and the mandible.