Retraction and rotation of the mandibular arch with buccal shelf bone screws to resolve Class III skeletal malocclusion.

OBJECTIVES

To elucidate the retraction effectiveness of extra-alveolar mandibular buccal shelf (MBS) bone screws anchorage relative to the presence of mandibular third molars and ANB angle in Class III patients.

MATERIALS AND

METHODS

This retrospective study included 45 patients (mean age = 22.2 ± 6.7 years) treated with bilateral MBS stainless steel bone screws (2 × 12 mm). Patients were subgrouped based on mandibular third molar status and ANB angle (≤-2° vs > -2°). Pretreatment and posttreatment cephalograms were superimposed and analyzed. Statistical tests included analysis of variance, paired and independent t-tests, and linear regression.

RESULTS

Mean retraction of mandibular first molars and incisors was 1.86 ± 1.36 mm and 2.89 ± 1.64 mm, respectively, over an average of 9.0 months. Retraction ≥ 3 mm was significantly associated with treatment durations ≥ 12 months (P < .001). No significant differences in retraction outcomes were found among third molar subgroups. The severe malocclusion group (ANB ≤ -2°) showed greater molar retraction and overjet increase. A moderate positive correlation was found between molar crown retraction and retraction duration (R2 = 0.282, P < .001).

CONCLUSIONS

MBS bone screws provide effective, minimally invasive anchorage for mandibular whole-arch retraction in Class III patients. Treatment outcomes are not hindered by third molars in adolescents, and longer retraction duration enhances distal movement.