Skeletal and Dentoalveolar Effects of Maxillary Protraction Using Tooth- and Miniscrew-Anchored Devices in Patients with Class III Malocclusion with Maxillary Deficiency: A Retrospective Follow-Up Study

Introduction: This retrospective study aimed to determine skeletal and dental changes after a growth spurt and shortly after treatment using a facemask in skeletal Class III malocclusion with maxillary deficiency. Methods: We retrospectively studied 50 patients (25 patients per group) with skeletal Class III malocclusion who underwent facemask treatment with tooth-anchored (T-A, mean age 7.92) and miniscrew-anchored (M-A, mean age 9.84) intraoral appliances. In both groups, the facemask applied a traction force of 350-400 g to each side, such that the traction was directed 30 degrees forward and downward. Lateral cephalometric radiographs were obtained from all patients before (T1), immediately after (T2), and at an average of 37.11 months after maxillary protraction (T3). A total of 13 cephalometric measurements were analyzed to determine the skeletal and dental changes. A paired t-test was used to verify the effects before, after, and during follow-up periods in each group. Results: An anteroposterior relationship, the values of SNA and ANB, evident in both groups at T2, was significantly improved in the M-A group (p < 0.05). However, the values of ANB and MP-SN, which indicate the relapse of anteroposterior and vertical relation of maxilla and mandible, were significantly higher in the T-A group compared with the M-A group during follow-up period. The maxillary first molars were significantly more extruded and maxillary incisors were more protruded in the T-A group than the M-A group, and this persisted at T3 (p < 0.05). Conclusions: Miniscrew-anchored maxillary protraction increased the skeletal improvement of anteroposterior relationship and reduced the dental and skeletal relapses compared with tooth-anchored maxillary protraction in growing patients with a hyperdivergent patterns and skeletal Class III malocclusion.

Automated summary

This retrospective study compared the skeletal and dental changes after treatment in skeletal Class III malocclusion patients using different fixation methods (tooth-anchored and miniscrew-anchored). The results showed that miniscrew-anchored treatment was more effective in improving the anteroposterior relationship and reducing dental and skeletal relapses in growing patients with hyperdivergent patterns and skeletal Class III malocclusion.