Junghan Kim, Yoon-Ah Kook, Mohamed Bayome, Jae Hyun Park, Won Lee, Hojae Choi, Noha H. Abbas

Comparison of tooth movement and biological response in corticotomy and micro-osteoperforation in rabbits.

- Korean J Orthod 2019;49:205–213

Recently, with the preference for non-invasive procedures, micro-osteoperforation has emerged as an alternative to corticotomy. Since the design of corticotomy has not been established to date, this study comparing the treatment effect of various design of cortiocotomy and micro-osteoperforation would be valuable for most orthodontists.

Q1. In this study, the amount of tooth movement was evaluated at 4 weeks after orthodontic force application. The tooth moved 1.72 mm in the control group, and 2.27–2.52 mm in the intervention group. Considering that the tooth movement is typically 1 mm for a month, these amount of tooth movement is somewhat excessive. Evaluation of tooth movement needs to be accompanied by the change of tooth inclination. In particular, I was wondering whether the large amount of tooth movement in the experimental group was due to excessive tipping movement.

Q2. The authors defined the intervention site, as the mesial surface of the first premolar roots (pressure side); and the non-intervention site, as the distal surface of the first premolar root (P1–P2, tensional side). The effect of cortiocotomy is not limited to the area where it is performed. Previous studies have shown that corticotomy performed on one side (pressure side) also affects bone metabolism on the opposite side (tensional side). Is there any reason that P1–P2 was chosen as the non-intervention site? It is thought that a non-intervention site would be set up as a site that is not affected by corticotomy.

Q3. When comparing between indentation corticotomy group and micro-osteoperforation group, the number, size and depth of indentation was different between groups. The perforation design should be identical to evaluate whether flap elevation affects tooth movement or not. Why did the authors make a difference in indentation design between the two groups.