Effect of micro-osteoperforations on rate of space closure by mini-implant supported maxillary anterior en-masse retraction: A randomized clinical trial

Micro-osteoperforations is one of the non-invasive surgical techniques used in attempt to accelerate OTM. Conflicting reports on its effectiveness has been reported in the literature.The objectives of this trial were to investigate the effect of micro-osteoperforations on the rate of space closure and on molar anchorage loss during mini-implant supported maxillary anterior en-masse retraction.A single center, parallel arm, randomized controlled trial was conducted.Sixty, male and female subjects (age range 16-25 years) having Class I bimaxillary protrusion or Class II div 1 malocclusion, who required fixed mechanotherapy with either upper 1st premolar or all four 1st premolar extractions were allocated into two groups using 1:1 allocation ratio. The allocation was done by block randomization method with a block size of 6. In the experimental group, 5 MOPs per side were performed only once just before the en-masse anterior retraction. Mini-screws were placed in order to obtain maximum anchorage. Impressions were taken every month till 4 months and rate of space closure was measured on 3D study models.Data of 27 subjects in control (attrition ​= ​3) and 28 subjects in experimental group (attrition ​= ​2) were analyzed at the end of this trial. There was a statistically significant increase in the rate of en-masse retraction for the 1st month(p ​= ​0.001,95%CI, 0.17, 0.37 ​mm) but there was no statistically significant difference for the subsequent 2nd (p ​= ​0.450,95%CI,0.13,0.43 ​mm), 3rd(p ​= ​0.204,95%CI,0.23,0.47 ​mm) and 4th month (p ​= ​0.680,95%CI,0.21,0.41 ​mm) between experimental and control groups. There was also no difference (p ​> ​0.05) in molar anchorage loss between both groups at all time intervals.Micro-osteoperforations (MOPs) did not accelerate the rate of anterior en-masse retraction over a period of 4 months; however, it temporarily increases the rate of retraction only for first month and no affect on molar anchorage.The trial was registered at www.ctri.nic.in with CTRI No- CTRI/2019/03/018140).