# Comparison of dental effects of traditional and clear twin block: A randomized clinical trial

## TL;DR

This study compares the dental effects of traditional and clear twin block appliances in treating skeletal Class II patients.

## Contribution

The study provides a direct comparison of dental outcomes between traditional and clear twin block appliances in a clinical trial.

## Key findings

- CTB and TTB showed significant differences in IMPA at six months.
- TTB caused more lower incisor protrusion than CTB.
- No significant dental changes were observed in the CTB group over six months.

## Abstract

Growth modification is a strategy for the treatment of skeletal Cl II patients. Clear twin block (CTB) is a modification of traditional twin block (TTB), which is made from thermoplastic sheets instead of acrylic resin and wire. This study compared the dental effects of the clear and TTBs.

In this randomized clinical trial, 60 growing skeletal Cl II patients with dental Cl II div 1 malocclusion were selected and randomly divided into two groups: TTB and CTB. Cephalometric radiography and stone models were taken before treatment (T1) and six months (T2) after appliance insertion. Data were analyzed using independent t-test and paired t-test at the 0.05 significance level.

There was a significant difference between CTB and TTB in IMPA at T2 (P<0.05). Intragroup comparisons showed no significant change from T1 to T2 in the CTB group and for U1-SN and U1-Pal amounts in the TTB group. T1-T2 comparison showed a significant change in IMPA in the TTB group (P<0.05).

TTB showed more protrusion of lower incisors compared to CTB.