# Comparison of Treatment Outcome of Forsus Fatigue Resistant Device With Single Versus Double Wires: A Randomized Controlled Trial

## TL;DR

This study compares the effectiveness of a dental device with single versus double wires for correcting Class II malocclusion in teenagers.

## Contribution

The study provides new empirical evidence on the clinical outcomes of using single versus double wires with the Forsus device in Class II malocclusion treatment.

## Key findings

- Both single and double wire groups achieved Class I molar relationship and overjet correction.
- Sagittal correction and mandibular incisor proclination were significant in both groups.
- No significant differences were found between the two treatment groups.

## Abstract

Background: Skeletal Class II malocclusion with mandibular retrusion as primary etiology is usually managed with treatment strategies such as growth modification, orthodontic camouflage, and surgical correction, depending on the patient’s age and severity of the discrepancy. Patients in the circumpubertal age group are commonly treated with growth-modification appliances. Although removable functional appliances can effectively stimulate mandibular growth, their success is frequently limited by patient compliance and interference with oral function. Fixed functional appliances provide a compliance-independent alternative; however, achieving consistent clinical efficiency and patient comfort remains a challenge. Among these, the Forsus Fatigue Resistant Device (FFRD; 3M Unitek, Monrovia, CA, USA) has emerged as a reliable option, offering continuous orthopedic forces and convenient adjustability for effective Class II correction.

Objective: To evaluate the effectiveness of the FFRD with single versus double wires.

Materials and methods: The study included 24 subjects with skeletal Class II malocclusion, aged 15-21 years. Subjects were randomly assigned to two groups, each consisting of 12 individuals. Group 1 was treated with the Forsus device using single-slot brackets, while Group 2 incorporated the Forsus device with double-slot brackets. Linear and angular parameters were measured on lateral cephalograms before and after Forsus therapy. Statistical analysis included the Shapiro-Wilk, independent t-test, ANOVA, Friedman, and Mann-Whitney U tests.

Results: Class I molar relationship, overjet, and overbite correction were achieved in both the treatment groups. Sagittal correction (p<0.001 and p<0.001), mandibular incisor proclination (p<0.001 and p=0.012), and change in mandibular plane angle (p<0.001 and p=0.002 for groups 1 and 2 respectively) were significant in both the treatment groups. However, no significant differences were found between the treatment groups.

Conclusion: In both treatment groups, correction of Class II malocclusion was primarily dentoalveolar in nature. The use of double wires in double-slot brackets with the Forsus device did not result in statistically significant enhancement of mandibular growth, nor did it mitigate the labial inclination of mandibular incisors.