# Research to Improve Fixed Orthodontic Treatment of Thirty Six Angle Class II Severe Malocclusions with Premolar Extractions Using a Modified Orthodontic Scientific Simulator

## TL;DR

This study compares TiNb and NiTi orthodontic wires in treating severe malocclusions using a scientific simulator to determine which performs better.

## Contribution

The study introduces an optimized protocol for using TiNb and NiTi wires in treating class II severe malocclusions with premolar extractions.

## Key findings

- TiNb wires showed permanent deformation in the first stage, underperforming compared to NiTi wires.
- Little’s Irregularity Index was better for NiTi wires on 0.016 wires, indicating superior alignment.
- Metal stress analysis using stereo microscopy revealed differences between TiNb and NiTi wire performance.

## Abstract

This study aimed to evaluate the new orthodontic TiNb wires in direct comparison to the gold standard in orthodontics, NiTi wires, when treating. There is limited literature on patients with severe malocclusions being treated from start to end with TiNb, and TiNb wires were mostly used in the final stages of treatment. Our protocol consisted of three orthodontic wires: 0.016, 0.016 × 0.025, and 0.019 × 0.025 for levelling and aligning the stage and 0.019 × 0.025 stainless steel for the finishing stage, in order to treat the same case reproduced on a modified scientific simulator. The bracket system used was made by GC slot 0.22, TiNb wires made by Morita, and NiTi wires produced by GC. We ligated all brackets using SS wire ligatures 0.008, and for anchorage, we used a transpalatal arch. The temperature of the scientific simulator was set between 20 and 25 degrees Celsius. We have used upper arches and studied the repositioning of upper ectopic canines and space closure in order to obtain an equilibrated maxillary arch. After each change of orthodontic wires, we scanned the upper arch using Medit i600 (Medit, Seoul, Republic of Korea). After concluding all stages on all upper arches, we assessed the results using LITTLE’s Irregularity index and stereo microscopy to explain metal stress on NiTi and TiNb. We propose an optimized process for using TiNb and NiTi wires when treating class II severe malocclusions with premolar extractions. Thus, we observed permanent deformation for all 0.016 TiNb wires used in the first stage, so TiNb underperformed in comparison with NiTi. Also, the Little’s Irregularity Index was superior in the NiTi wires group on 0.016 wires, verifying the change of state in the TiNb wires group.