Evaluation of the success rate of single- and dual-thread orthodontic miniscrews inserted in the palatal side of the maxillary tuberosity.

BACKGROUND: Recent studies have reported that the placement of miniscrews for orthodontic anchorage in maxillary tuberosity is anatomically safe and can aid in achieving efficient tooth movement mechanically. However, the success rate of miniscrews placed on the palatal aspect of the maxillary tuberosity has not yet been elucidated. This study aimed to evaluate the success rate of single- and dual-thread miniscrews inserted in the palatal aspect of the maxillary tuberosity. METHODS: A total of 101 miniscrews (17 single-thread miniscrews: diameter 2.0 mm, length 10 mm; 84 dual-thread miniscrews: diameter 2.0 mm, length 12 mm) placed in 61 patients (6 males, 55 females; mean age = 30.9 +/- 8.66 years) were retrospectively examined. Miniscrews that could be maintained for orthodontic anchorage for more than 6 months were considered successful. The direction of placement, bone-miniscrew contact (BMSC) rate, and survival of miniscrews were measured using cone-beam computed tomography. RESULTS: The overall success rate of single-thread miniscrews was 82.4% and that of dual-thread miniscrews was 94.0%. There was no significant difference in the overall clinical success rate between the two designs. Sex, mandibular plane angle, and malocclusion type did not significantly affect the success rate in both groups. CONCLUSIONS: Both single- and dual-thread miniscrews placed on the palatal aspect of the maxillary tuberosity showed high success and BMSC rates. However, there were no significant differences in the overall success rate and BMSC rate between the two miniscrew designs.