The effects of a common stainless steel orthodontic bracket on the diagnostic quality of cranial and cervical 3T-MR images: a prospective, case-control study

Abstract OBJECTIVES: To evaluate the effect of orthodontic stainless steel brackets and two different types of archwires (stainless steel and nickel-titanium) on the diagnostic quality of 3T-MR images. METHODS: This prospective, case-control study was conducted following STROBE guidelines. The imaging protocol consisted of the axial Fluid Attenuated Inversion Recovery (FLAIR) and axial oblique double echo proton density (PD) and weighted/turbo spin echo (TSE) T2-weighted sequences for brain, paranasal sinuses and cervical region evaluation; sagittal TSE T2w, sagittal TSE T1w and axial T2* Gradient echo sequences (GRE) sequences for the cervical vertebrae; axial and coronal TSE T2w images for the head and neck structures; and sagittal, axial and coronal PD and TSE T2-weighted sequences for the temporo-mandibular joint. Two experts in neuroradiology evaluated the images. The statistical analysis was performed at the level of anatomical districts. The following statistical methods were used: descriptive statistics, Cohen's kappa coefficient (k), Kruskal-Wallis test, pairwise comparisons using the Dunn-Bonferroni approach. Significance was set at p≤0.05. RESULTS: 80 patients were included, providing 80 MRI. The presence of stainless steel brackets with or without archwires negatively influenced the MR images of the cervical region, paranasal sinuses, head and neck region and cervical vertebrae but did not influence the MR images of brain and temporomandibular joint regions. CONCLUSIONS: Patients with a stainless steel multi-bracket orthodontic appliance should remove it before cervical vertebrae, cervical region, paranasal sinuses and head and neck MRI scans. The brain and temporomandibular joint regions MRI should not require the removal of such appliances.