Failure of Orthodontic Mini-implants by Patient Age, Sex, and Arch; Number of Primary Insertions; and Frequency of Reinsertions After Failure: An Analysis of the Implant Failure Rate and Patient Failure Rate

Abstract

This study aimed to analyze and compare the failure rate of orthodontic miniimplants (OMIs) in terms of the number of implants (implant failure rate [IFR]) and patients (patient failure rate [PFR]) according to the age, sex, and arch of the patients, the number of primary insertions, and frequency of reinsertions after failure. A total of 394 OMIs (1.2 mm in diameter; 7.0 mm in length) were inserted in 125 patients (24 male and 101 female, mean age 21.95 ± 7.60 years). IFR and PFR were evaluated according to the age and sex of the patient, the number of primary insertions, and the frequency of reinsertions after failure. PFR was 40.08% and IFR was 18.27% after the first insertions. PFR was higher than IFR regardless of the number of OMIs inserted. IFR increased with an increase in the frequency of reinsertions, reaching 66.67% after the fourth insertion, whereas PFR decreased to 25.00% after the second insertion and to 66.67% after the third and fourth insertions. The overall PFR and IFR were 40.80% and 19.29%, respectively. Although male patients, young patients, and location in the mandible showed higher PFR and IFR, there were no significant differences between PFR and IFR according to the sex, age, or arch. PFR was higher than IFR in this study, indicating that the treatment process could be more strongly affected by PFR than IFR. The failure rate can increase with the frequency of OMI reinsertions after failure. Sex, age, and arch may have no correlation with primary or recurrent OMI failure.

The Orthodontic Mini-Implants Failures Based on Patient Outcomes: Systematic Review

“…34 Meanwhile, the result of Kim et al study to evaluate the failure rate of orthodontic mini-implants in the implant failure rate (IFR) and patient failure rate (PFR) showed that IFR and PFR were higher in men than women, although the difference was not significant. 13 Similar to the others, Yoshida et al 35 and Malik et al 25 study also showed that the failure rates of implant were significantly higher in males compared to females. According to Ono et al, the cortical bone between first molar and the second premolar is often the site of implantation thicker in men than in women.…”

“…Kim et al compared PFR and IFR in the maxilla and mandible and then found a higher failure rate in the mandible than the maxilla though not significant. 13 Aly et al 22 and Melo et al 9 said that the loss of stability of mini-implants was more significant in the mandible than in the maxilla. Sreenivasagan et al also reported that mobility leading to failure occurs more often on the right side and in the mandible than the maxilla.…”

“…9 10 11 According to some researchers, mini-implants are successful if the implants are stable in the jawbone until the end of treatment or until the planned time of removal. 12 13 Kaul and Dhanani mentioned that the mini-implants' success could be interpreted by the presence of minimal mobility and inflammation and the ability to obtain function correction through direct and indirect anchorage. 1 Similar to orthodontic mini-implant, according to Rodrigues et al, the quality and quantity of bones, such as their density and morphology, were the only predisposing factors for the successful osseointegration of dental implants.…”

Failure rates of miniscrews inserted in the maxillary tuberosity

“…After insertion, primary stability was evaluated by an expert operator, with cotton tweezers. Miniscrews were labelled as successful if they remained functionally stable in MT until the end of treatment or until intentional removal, while miniscrews were labelled as failed if they had any discernible mobility or had become loose during orthodontic treatment 10 12 Vertical analysis was done using measurement of mandibular plane angle (MPA) at pre-treatment cephalograms.…”

“…Miniscrews can be labelled as successful if they remain functionally stable in jaw bones until the end of treatment or until intentional removal 10 . Meanwhile, miniscrews are labelled as failed if they had any discernible mobility or had become loose during orthodontic treatment 11 …”