Radiofrequency-induced Heating near Fixed Orthodontic Appliances in High Field MRI Systems at 3.0 Tesla

Abstract

Based on the data of our experimental study the radiofrequency-induced heating of orthodontic brackets during high field MRI at 3 Tesla can be categorized as negligibly low. Even the clinical routine examination of the head at 3 Tesla using high-energetic pulse sequences can be applied without hesitation in patients with fixed orthodontic appliances.

Evaluation of magnetic resonance imaging issues of titanium and stainless steel brackets

“…In our trial, no bracket temperature increase exceeding 0.1°C has been found, which corresponds with other studies 30,31 . Contrarily, Görgülü et al 29 reported a stainless steel bracket set heating up to 3.04°, while Hasegawa et al 41 noted a temperature rise of 2.61°.…”

“…Majority of studies on orthodontic appliances showed that SS brackets caused moderate to significant MR image distortions [23][24][25][26][27][28] . MR safety studies reported negligible heating and no risk of displacement for properly fixed brackets [29][30][31][32] . Since most orthodontists prefer SS brackets (86% and 95% of the specialists in the US and the UK, respectively) 33,34 , patients with these brackets are not acceptable for MRI.…”

Effect of orthodontic brackets and different wires on radiofrequency heating and magnetic field interactions during 3-T MRI

“…Our findings for the deflection angle and qualitative torque measurements are also compatible with the existing data in the literature. 20,23 The present study differs from previous similar studies [18][19][20]23 in that we examined not only the RF heating but also the MF interactions during 3-T MRI by using natural human teeth. It should be noted that this study did not evaluate the changes on the bonding strength of the brackets or changes in the amount of force applied by wires.…”

“…In the previous studies, which aimed to measure RF heating during MRI, artificial teeth were used 18 or the orthodontic appliances were inserted directly into gelled phantom models. 19,20 In the present study, to simulate actual clinical conditions, 40 human teeth were used for the application of brackets and wires.…”

Effect of magnetic resonance imaging on microleakage of amalgam restorations: an in vitro study

“…Interestingly, these authors clearly stated that the increase in microleakage following MRI might be attributed to the thermoelectromagnetic convection induced by exposure to EMFs that was supposed to be responsible for the enhancement of the diffusion process, grain boundary migration and vacancy formation resulting in microleakage. However, some researchers [5][6][7] believe that no conclusive evidence exists to prove such temperature changes following common MRIs. Görgülü et al 5 evaluated the heating and magnetic field interactions of fixed orthodontic appliances with different wires and ligaments in a MRI environment.…”