Factors associated with the Success of Orthodontic Miniscrews

Nowadays miniscrews are widely used as skeletal anchorage in orthodontics. However the success rate of miniscrews is less than that of osseointegrated implants. The aim of this retrospective study was to evaluate factors influencing the success rate of orthodontic miniscrews. Data of 244 miniscrews in 122 patients (99 females and 23 males, with a mean age of 19 years and 6 months) were collected. Logistic regression analysis was used to evaluate the effect of age, gender, placement side and insertion torque on the success rates of miniscrews. The overall success rate of miniscrews was 90.6% in the present study (221/244). Logistic regression analysis showed that the success rate of miniscrews was not under the influence of variables such as gender, placement side and miniscrew brand. However, age groups and insertion torques over 10 Ncm decreased miniscrew success rates. In this context, the success rates of miniscrews in patients under 16 years of age was less than those in patients over 16 years of age (P<0.001) and the success rates of miniscrews with insertion torques ≤10 Ncm were higher than those with insertion torques over 10 Ncm (P=0.019).Conclusion. We concluded that patients under 16 years of age and insertion torques over 10 were increased the failure of orthodontic miniscrews.