Long-term stability of skeletal Class III patients treated with splints, Class III elastics, and chincup.

Long-term results from orthopedic management of skeletal Class III malocclusions are sparse. The purpose of this study was to evaluate the stability of results after facial growth and treatment with splints, Class III elastics, and chincup (SEC III) and to investigate the main determinants of relapse. Data from pretreatment, posttreatment, and long-term (at least 3 years after retention) serial cephalograms of 52 patients who received SEC III treatment were studied: only those with long-term data when growth had ceased (women over 18 and men over 21 years of age) were selected. At the end of the follow-up period (an average of 9 years), only 6 of the 52 patients had clinical relapse (overjet <or= 0). Low Wits appraisal, ANB angle, and overbite, and high SNB angle were the best predictors of relapse at the end of the treatment. Significantly greater decreases of the Wits appraisal and increases of ramus length during the follow-up were further associated with relapse. SEC III is a reliable treatment for skeletal Class III malocclusions. Long-term stability can be enhanced by a deeper overbite and the best possible skeletal correction. The results suggest that the correction occurs with no mandibular rotation but might be better with forward rotation.