Comparative evaluation of the maxillary canine retraction rate and anchorage loss between two types of self-ligating brackets using sliding mechanics

Methods of measuring distal canine movement and rotation- A review

This article provides an overview of the various methods for measuring distal canine movement and rotation during retraction. Various databases, including PubMed Central, Science Direct, Wiley Online Library, the Cochrane Library, Textbooks, Google Scholar, and Research Gate, and a manual search up until September 2022, were used to search for various methods of measuring distal canine movement and rotation during retraction. After excluding the duplicate articles, the papers explaining these techniques were included. Four significant techniques were identified. The digital method with 3D superimposition is the safest, most accurate, and most accessible of the methods reviewed.

Comparison of retraction efficacy of titanium-molybdenum and titanium-niobium alloy wires – A prospective split-mouth study

Objectives:

The study aimed to compare the efficacy of Titanium-Molybdenum (Ti-Mo) and Titanium-Niobium (Ti-Nb) alloy wires as retraction springs, by comparing: The amount and rate of canine retraction, the degree of canine rotation, the change in axial inclination of canines, and the associated anchorage loss.

Material and Methods:

All 17 participants (age: 18–25 years) to be treated with the first premolar extraction approach by canine retraction were assigned Ti-Mo and Ti-Nb alloy T-loop springs to either of the upper quadrants randomly. Digital intraoral 3-D scans and panoramic radiographs orthopantomagram (OPG) were taken before (T0) and after (T1) the study period (4 months). 3-D superimposition was performed and using the digital models and OPG, changes in canine position, angulation, and anchorage loss were compared between the two groups.

Results:

There was no significant difference between the two treatment groups for all the parameters pertaining to maxillary canine retraction, that is, canine retraction (P = 0.72), change in axial inclination of canines (P = 0.71), rotation of canines (P = 0.74), and anchorage loss (P = 0.13) as well as extraction space closure (P = 0.74).

Conclusion:

Ti-Nb and Ti-Mo alloy wires show a similar potency for use in retraction mechanics for orthodontic space closure.

Torque expression by active and passive self-ligating brackets in patients with four premolar extractions: A retrospective study

OBJECTIVE

Appropriate torque expression contributes to ideal treatment outcomes both clinically and aesthetically. Whether active and passive self-ligating brackets (SLBs) have different torque-control capability in vivo has never been reported. The purpose of present study was to explore whether there was difference in torque expression in active and passive SLBs.

SETTING AND SAMPLE POPULATION

In this retrospective study, 225 patients with four first premolar extractions were enrolled. For each patient, the digital lateral cephalometric radiographs were taken before and after treatment.

MATERIALS AND METHODS

The study consisted of 2 groups: 111 subjects were treated with passive SLBs (Damon Q, Ormco) and 114 subjects with active SLBs (Empower 2, American Orthodontics). Measurements to determine skeletal changes and incisor inclination were obtained from cephalometric tracings using Dolphin software (version 11.8, USA). Comparisons in both groups and intergroups were compared using t tests and chi-square test.

RESULTS

Significant differences in the variation of U1-SN(°), U1-NA(°), L1-NB(°) and L1-FH(°) were found between two groups. More labially inclined maxillary incisors were found in active SLB group, while more labially inclined mandibular incisors were observed in passive SLB group.

CONCLUSIONS

With the present prescription set in the two brackets, active SLBs achieved more proclined maxillary incisors and retroclined mandibular incisors. Clinicians should take torque expression of brackets into consideration during orthodontic treatment.