Letter to the Editor

To: Editor, The Angle Orthodontist

Re: A comparison of treatment effects of total arch distalization using modified C-palatal plate vs buccal miniscrews. Sang Kyu Lee; Noha H. Abbbas; Mohamed Bayome; Un-Bong Baik; Yoon-Ah Kook; Mihee Hong; Jae Hyun Park. The Angle Orthodontist. 2018;88: 45-51.

The study by Lee et al. (doi: 10.2319/061917-406.1.) was very interesting and we appreciate the clinical part of the research. However, we would like further information regarding some aspects of the study.

The paper stated that distalization was started immediately after placing MCPPs. In the buccal mini screw (BMS) group, distalization was initiated on 0.017X0.025-inch SS wires in 0.018-inch slot brackets. In this case, we assume that there was no standardized distalization method other than that coils or elastics were used. The distalization force provided by coils or elastics was not specified for the BMS group (but was 300 grams in MCPP group).

Both the initial amount of distalization required to correct the Class II relationship (Class II relationship may be more severe in the MCPP group) and the duration of distalization were not documented. Time-based comparison of the amount of distalization or determining the amount of distalization per month would be helpful for interpreting the results.

Figure 1B and Figure 4B, both used to illustrate BMS retraction, are not matching. A hook is welded on the bracket in Figure 1B, on the other hand, the hook is crimped on the archwire in Figure 4B. Biomechanically, the two different ways of force application would result in different force distributions. In the Figure 1B, the central incisors are not bonded. However, the position of the upper incisors is one of the evaluated parameters.

We would appreciate your further comments on the details of the study and how they might affect interpretation of the results.