Compensation of skeletal Class III malocclusion by isolated extraction of mandibular teeth: Part 2: Skeletal, dentoalveolar and soft tissue parameters in comparison with nonextraction Class III therapies.

OBJECTIVES

To retrospectively compare two compensatory approaches taken in skeletal Class III patients during the main treatment stage, including a study group of multiband treatment plus isolated extraction of mandibular teeth and a control group of multiband treatment without extraction of teeth.

PATIENTS AND METHODS

The extraction group included 22 (12 female, 10 male) patients receiving compensatory multiband treatment for a mean of 3.47 ± 1.14 years and 16.22 ± 1.92 years old at debonding. The nonextraction group included 24 (14 female, 10 male) patients undergoing multiband treatment for 2.76 ± 1.28 years and 15.38 ± 1.46 years old at debonding. Lateral cephalograms obtained at baseline and upon completion of active treatment were traced for skeletal, dentoalveolar, and soft tissue parameters. Welch and Wilcoxon tests were used to analyze intergroup differences (initial values, final values, initial-to-final changes) and within-group differences (p < 0.05).

RESULTS

Upon completion of active treatment, the only significant intergroup differences were noted for U1NA and L1ML. Significant within-group changes over the courses of treatment were seen for SNB, MLNL, U1NA, U1NL, L1NB, L1ML, H-angle, ULipEL, and LLipEL (extraction group) or for SNB, ANB, individual ANB, Wits appraisal, U1NA, U1NL, H-angle, Naslab-a, ULipEL, and LLipEL (nonextraction group). Parameters that changed by significantly different amounts in both groups included Wits appraisal, L1NB, L1ML, and LLipEL.

CONCLUSION

The added value of isolated extraction therapy basically lies in increasing the potential for retruding the lower incisor inclinations, so that compensatory treatment becomes an option even in selected patients presenting with adverse occlusal situations that would otherwise require orthognathic surgery. Given the successful outcomes in both groups, which had been established by Peer Assessment Rating (PAR) scores, it was possible to define the skeletal, dentoalveolar, and soft tissue characteristics of successful treatment more precisely than before.