Can a patient with metal orthodontic (orthodontic) braces undergo a Magnetic Resonance Imaging (MRI) scan?

MRI Safety with Metal Orthodontic Braces

Patients with metal orthodontic braces should have them removed before MRI scans of the head and neck region, particularly if stainless steel brackets are present, as they cause significant artifacts that render images non-diagnostic. 1, 2, 3

Types of Orthodontic Brackets and MRI Compatibility

Different types of orthodontic brackets have varying effects on MRI image quality:

Stainless Steel Brackets

• Always require removal before MRI scans of the head and neck
• Cause 100% non-interpretability of all anatomic areas 2
• Create maximum distortion, making images completely non-diagnostic 3
• Negatively impact imaging of cervical region, paranasal sinuses, and head and neck region 4

Ceramic and Polycarbonate Brackets

• Do not require removal before MRI scans
• Cause minimal to no artifacts 3
• Provide diagnostic-quality images of all regions 2, 5

Titanium Brackets

• May not require removal depending on the area being imaged
• Cause artifacts only in the oral cavity (approximately 20% of cases) 2
• Generally allow diagnostic-quality images of other head and neck regions

Ceramic Brackets with Metal Slots

• May not require removal depending on the area being imaged
• Cause artifacts only in the oral cavity (approximately 16.65% of cases) 2
• Create minimal distortion but images remain diagnostic 3

Decision Algorithm for MRI with Orthodontic Braces

1. Determine bracket material:

   • If stainless steel brackets → Remove before any head/neck MRI
   • If ceramic/polycarbonate brackets → No need to remove
   • If titanium or ceramic with metal slots → Proceed to step 2

2. Identify anatomical area being imaged:

   • If oral cavity is the primary area of interest → Remove all metal components
   • If brain, temporomandibular joints, or other head/neck regions → Titanium or ceramic brackets with metal slots may remain in place

3. Consider archwires:

   • All archwires (especially stainless steel) should be removed before MRI as they can be easily removed 2, 4

Important Considerations for Radiologists and Clinicians

• When MRI is contraindicated or artifacts would limit diagnostic value, consider alternative imaging modalities:

  • CT scan for evaluating bony structures 6
  • Ultrasound for soft tissue structures 6

• Metal orthodontic appliances can affect MRI quality through:

  • Signal loss and image distortion 7
  • Susceptibility artifacts in the orofacial region 5
  • Potential distortion in frontal lobe, orbits, and pituitary gland imaging 5

• The distance between the appliance and the area being imaged affects artifact severity:

  • Greater distance = less distortion and signal loss 7
  • Brain and temporomandibular joint MRIs may still be diagnostic with certain appliances in place 4

Fixed Retainers and MRI

• Stainless steel retainers cause artifacts in the oral cavity (86.65% of cases) but should only be removed if the oral cavity itself is under investigation 2
• Fiber-reinforced composite retainers do not distort images and need not be removed 3
• Titanium retainers and multi-stranded stainless steel retainers cause minimal distortion but images remain diagnostic 3

Technical Adjustments to Reduce Metal Artifacts

If removal is not possible, the following MRI parameters can help reduce artifacts:

• Use spin echo and fat-suppression protocols
• Lower magnetic field strength (1.5 Tesla vs. 3 Tesla)
• Smaller field of view
• Higher-resolution matrix
• Thinner slices
• Increased echo train length
• Increased receiver bandwidth 7

By understanding the specific impact of different orthodontic materials on MRI quality, clinicians can make informed decisions about when bracket removal is necessary, minimizing disruption to orthodontic treatment while ensuring diagnostic-quality imaging.