MRI in Dental Imaging: Beyond the Bones

Learning objectives

• Explain the basic principles of MRI and how it differs from other imaging modalities

• Identify the key dental and maxillofacial structures best visualized by MRI

• Describe clinical indications for MRI in dental practice

• Recognize the role of dental hygienists in supporting MRI based diagnostic

• Compare MRI to traditional dental imaging methods in terms of safety, resolution, and applications

What’s hiding in the soft tissue?

Dentistry has long relied on x-rays and CBCT scans for hard tissues exams

What about muscles, nerves, discs, and glands?

• MRI

X-rays and CBCTs are like a blueprint of the house (hard walls), MRI is like seeing where the plumbing and wires (soft tissues) are

What is MRI?

Magnetic resonance imaging

• uses strong magnetic fields and radio waves to create detailed images

• no ionizing radiation- safe for repeated use

• best for soft tissue contrast

• common in medicine for brain, joints, hearts…and now teeth!

MRI vs Traditional Dental Imaging

MRI isn’t replacing dental x-rays, it’s complementing them, especially for soft tissue diagnostic

Uses in Dentistry

TMJ Disorders

• shows disc position, joint fluid, inflammation

  • no other imaging does this as clearly

• important for distinguishing muscle pain vs joint dysfunction

Salivary Glands

• detects tumors, blockages, or sialoliths

Pulp Tissue and Nerves (Experimental Use)

• can visualize inflamed or necrotic pulp

  • still being studied but looks promising

Oral pathology

• evaluation of soft tissue massess

• differentiates between inflammatory and neoplastic lesions

Specific case examples

Patient with jaw pain when chewing, jaw locks, no visible swelling, and no significant findings on PANO

• MRI can reveal disc replacement and/or joint inflammation that is not visible on a PANO

Patient with recurrent swelling on left cheek, no pain but discomfort, reduced salivary flow from parotid, negative PA and PANO findings

• MR sialography to view ductal system of gland

Trauma to central incisor, gray color, no mobility, asymptomatic, no fracture on CBCT

• MRI of the pulp chamber can detect changes in blood flow or inflammation in pulp

Dental MRI Technology

Most MRI machines used are medical grade, full body

New tech is emerging

• Nano MRI, ORAL-MR, Fraunhofer MRI scanner

Shorter scan times, small and focused FOV size, high-resolution for small oral structures

Scan time and experience

Takes 15-45 min

• depends on region scanned, image resolution needed, patient motion

Comfortable, non-invasive, often done without contrast

Limitations and Challenges

Physical Limits

• metal artifacts-metal restorations, braces, or implants distorts MRI images

• motion sensitivity-blurry images if movement (kids, anxiety)

• claustrophobia-enclosed space and loud sounds

• cost and time-MRIs are expensive and can take 20-45 min or more

NOT ideal

• routine cavity checks

• detailed images of enamel or restorations

• patients with inability to sit still for 20-40 min

Most dental clinics won’t have MRI, but may refer patient to a medical imaging center

Ethical and safety considerations

Always screen contraindications

• pacemakers, cochlear implants, certain metallic restorations

• MRI-safe environments are highly controlled

• MRI has no radiation, but strict safety protocols apply

Role of the DH

Know when MRI might be indicated

Take a thorough history (pacemakers, metal implants, etc)

Educate patients on need and process

• no metal, may take 30+ min, completely painless

Record referrals and findings

Research and future of MRI in dentistry

Explore the uses for

• caries detection (especially early stage lesions)

• high resolution dental MRI for root canal anatomy

• AI-enhanced MRI interpretation for diagnosis and treatment

Final thoughts

MRI opens new windows into dental diagnostics

It complements, no replaces, traditional imaging

As technology improves, MRI may become standard in complex dental cases

Stay informed- you’re part of the future of dental imaging