Three-Dimensional Digital Superimposition of Orthodontic Bracket Position by Using a Computer-Aided Transfer Jig System: An Accuracy Analysis.

Jae-Hyun Park,Song Hee Oh,Jin-Young Choi,Seong-Hun Kim

doi:10.3390/s21175911

Abstract

Accurate bracket placement is essential for successful orthodontic treatment. An indirect bracket bonding system (IDBS) has been developed to ensure proper bracket positioning with three-dimensional computer-aided transfer jigs. The purpose of this study was to investigate the accuracy of bracket positioning by a one-body transfer jig according to the tooth type and presence/absence of a resin base. In total, 506 teeth from 20 orthodontic patients were included in this study. After initial dental models were scanned, virtual setup and bracket positioning procedures were performed with 3D software. Transfer jigs and RP models were fabricated with a 3D printer, and brackets were bonded to the RP model with or without resin base fabrication. The best-fit method of 3D digital superimposition was used to evaluate the lineal and angular accuracy of the actual bracket position compared to a virtual bracket position. Although all the measurements showed significant differences in position, they were clinically acceptable. Regarding the tooth types, premolars and molars showed higher accuracy than anterior teeth. The presence or absence of a resin base did not consistently affect the accuracy. In conclusion, the proper application of IDBS should be performed considering the errors, and resin base fabrication might not be essential in ensuring high-accuracy IDBS.

Highlights

Accurate placement of orthodontic brackets is one of the most important phases in comprehensive orthodontic treatment [1] in order to ensure the ideal occlusion described by Andrew’s six key principles [2,3]
In addition to the accuracy, the reproducibility, reduced chair time, and lower risk of saliva contamination are considered advantages of indirect bracket bonding system (IDBS) compared to the direct bracket bonding system [7,8,9,10,11]
The inclusion criteria for this study were: (1) teeth planned to be bonded with fixed orthodontic appliances using an indirect bonding system, (2) teeth in permanent dentition, (3) intact natural teeth without any defects or restorations, and (4) teeth to which the transfer jigs could be adapted in the planned position

Summary

Introduction

Accurate placement of orthodontic brackets is one of the most important phases in comprehensive orthodontic treatment [1] in order to ensure the ideal occlusion described by Andrew’s six key principles [2,3]. As the extraoral bracket position (i.e., indirect bonding system, IDBS) has been suggested to be as accurate as the intraoral direct bracket bonding by some authors, both direct and indirect bonding systems have been used to achieve the best orthodontic treatment results [5,6]. Before digital workflows were introduced into the IDBS, all the processes were performed manually, which required multiple time-consuming steps [15]. Digital software made the precise bracket placement possible with reduced lab time. After the brackets are placed accurately on the digital models, transferring them to the exact locations where the brackets are intended to be placed on the real teeth of the patient is important. Silicone materials and the combination of silicone materials with thermoplastic sheets have been introduced [16]

Methods

Results

Conclusion