Mini-implant supported canine retraction with micro-osteoperforation: A split-mouth randomized clinical trial

Abstract

Objectives: To investigate, using a split-mouth randomized clinical design, the effect of micro-osteoperforation (MOP) on mini-implant supported canine retraction using fixed appliances. Materials and Methods: Thirty subjects (seven males and 23 females) with a mean age of 22.2 (3.72) years were randomized into three canine retraction groups: Group 1 (MOP 4-weekly maxilla/8-weekly mandible; n = 10); Group 2 (MOP 8-weekly maxilla/12-weekly mandible; n = 10) and Group 3 (MOP 12-weekly maxilla/4-weekly mandible; n = 10) measured at 4-week intervals over 16 weeks. Subjects also completed pain (5-point Likert scale) and pain impact (Visual Analogue Scale) questionnaires. The primary outcome was the amount of canine retraction over 16 weeks at MOP (experimental) and non-MOP (control) sites. Results: Mean overall canine retraction was 4.16 (1.62) mm with MOP and 3.06 (1.64) mm without. After adjusting for differences between jaws, all MOP groups exhibited significantly higher canine distalization than the control group: 0.89 mm more (95% confidence interval [CI] = 0.19 to 1.59 mm; P = .01) in the MOP-4 group, 1.08 mm more (95% CI = 0.49 to 1.68 mm; P = .001) in the MOP-8 group and 1.33 mm more (95% CI = 0.55 to 2.10 mm; P = .002) in the MOP-12 group. All subjects reported pain associated with MOP with 60% classifying it as moderate and 15% severe. The main impact of this reported pain was related to chewing and speech. Conclusions: MOP can increase overall mini-implant supported canine retraction over a 16-week period of observation but this difference is unlikely to be clinically significant.

Effect of mini-screw-facilitated micro-osteoperforation on the rate of orthodontic tooth movement: a single-center, split-mouth, randomized, controlled trial

“…In line with previous studies, our results showed that, except for the T3 time interval in the MOP1 group, there was a significant increase in the rate of canine retraction compared to the contralateral control side in both groups at all time intervals [2,[23][24][25]. However, another splitmouth clinical trial study found no significant effect of MOP on the rate of tooth movement over a 3-month period [26].…”

“…In line with previous studies, our results did not show any difference in pain perception among three study groups [2,25,26]. However, since the retraction force was applied immediately after the MOP procedure, it is highly probable that the patients could not differentiate the orthodontic pain from the MOP pain.…”

“…However, human studies have not shown any such significant difference between men and women [31]. In previous human studies on MOPs, there were more female than male participants [2,25,26]. Whereas in the present study, we recruited an almost equal number of men and women to eliminate the potential effect of sex on the rate of orthodontic tooth movement.…”

“…In comparison with the traditional orthodontics, a clinical study over a 1-month period has shown that when perforations are made to one side of the maxilla, the procedure significantly increased the rate of tooth movement by 2.3-fold, causing little pain or discomfort to the patients [2]. In a splitmouth clinical study, over a period of 16 weeks, acceleration in canine retraction by 1.1 mm compared to the contralateral control side was reported [25]. In contrast, another well-designed clinical trial revealed that MOP was not effective in increasing the rate of orthodontic tooth movement over a 3-month study period [26].…”

MOPs and accelerated tooth movement: A biased conclusion?

“…2 If Sivarajan et al were "Unclear" about our randomization, all they had to do was look at Table III ("Comparison of the morphological characteristics of the patients in the control and experimental groups") in our manuscript. 3 Of the 8 characteristics that we measured, not a single one was different between the groups. Did our randomization work?…”