Effect of Two Different Penetration Depths of Micro-osteoperforation on the Rate of Orthodontic Tooth Movement: A Prospective Clinical Study

Abstract

Objective: The objective is to evaluate the effectiveness of two different penetration depths of micro-osteoperforations (MOPs) on the rate of orthodontic tooth movement over 60 days. In addition, the amount of pain and discomfort caused by the MOP was evaluated.

Materials and methods: A total of 22 patients (18-30 years) who need fixed orthodontic treatment were recruited and randomly assigned into two groups. Randomization for determination of the experimental side and depth of perforations was done using sealed envelopes. On each patient, the other side of the mouth worked as control side with no MOPs. Patients in group 1 (MOP-5) received 3MOPs on the buccal surface of the alveolar bone each at 5 mm depth, whereas patients in group 2 (MOP-7) received 3MOPs on the buccal surface of the alveolar bone each at 7 mm depth. The amount of canine retraction was measured every 30 days at two intervals on both sides of the mouth. Pain perception was measured after 1 h, 24 h, 72 h, 7 days, and 28 days of procedure. MOP-related pain was measured using a visual analog scale. The level of statistical significance was P ≤ 0.05.

Results: The result of the intra-examiner reliability using intraclass correlation coefficient more than 0.97 (P < 0.001), indicating excellent repeatability and reliability of the measurements. The baseline characteristics between groups were similar (P > 0.05). Both the groups demonstrated a significantly higher canine movement than the control group. No significant difference was seen between the MOP-5 and MOP-7 groups (P > 0.05) in terms of canine retraction. Mild-to-moderate pain was experienced only in the first 24 h of the procedure.

Conclusion: Three MOPs with a depth of 5 mm can be performed as an effective method to increase the rate of tooth movement. However, increasing the depth of perforation beyond 5 mm does not additionally enhance tooth movement.

Keywords: Micro-osteoperforation; orthodontic tooth movement; regional acceleratory phenomenon; visual analog scale.

Figure 1

Mini-implant with stopper set at 5 mm depth (a), Mini-implant with stopper set at 7 mm depth (b)

Figure 2

MOP procedure on the experimental side using mini-implant

Figure 3

150 g of force applied by the Closed NI-Ti coil spring from the power arm to the mini-implant for canine retraction

Figure 4

Canine retraction was measured as the distance between the cusp tip of the maxillary canine to the mesiobuccal cusp tip of the maxillary 1^st permanent molar at T0, T1 and T3 (blue dots)