Should elderly men with thyroid damage use dental shields?

Hello,

Welcome to icliniq.com.

I read your query.

Your concerns about additional thyroid exposure are completely understandable - especially given your history of early-life radiation injury and the fact that you have been on long-term thyroid hormone therapy. It is natural to be more cautious than the average patient.

In dental imaging, the use of a thyroid shield (also called a thyroid collar) is generally recommended when it does not compromise the diagnostic quality of the scan. However, for certain procedures - especially 3D (three-dimensional) cone-beam computed tomography (CBCT) scans - the shield can sometimes obstruct part of the imaging field, depending on the angle and area being scanned. This is likely what your oral surgeon’s office meant when they said it could “get in the way.”

A thyroid collar may not always be used during panoramic radiographs (OPG – orthopantomogram) and many CBCT (cone-beam computed tomography) scans because the collar can lie directly in the path of the primary X-ray beam, which may block or weaken the beam and create image artifacts.

This can distort important anatomical details, reduce diagnostic accuracy, or even make the scan unusable, leading to the need for repeat imaging and potentially increasing overall radiation exposure instead of reducing it.

A snug lead thyroid collar can sit directly in the path of the primary X-ray beam. This can:

1. Block or attenuate the beam.

2. Create artifacts (distortions) on the image.

3. Make the scan non-diagnostic.

4. Force a repeat scan (which actually increases radiation exposure).

Several professional reviews, including those by the AAOMR (American Academy of Oral and Maxillofacial Radiology), note that thyroid collars can interfere with these imaging modalities.

The ADA (American Dental Association) updated its guidance in February 2024 and states that: Routine use of lead aprons and thyroid collars is no longer recommended for dental radiography, because modern dental X-ray doses are very low and shielding can interfere with image quality.

So, the office is not being unreasonable to refuse a collar when it lies in the primary beam for a panoramic or CBCT image. Their explanation - “it can get in the way” - is technically accurate in many situations.

Given your personal medical history, including prior radiation exposure affecting your thyroid and the fact that you are on long-term thyroid hormone replacement therapy, you have a valid and reasonable basis to be more cautious about further radiation exposure and to request additional thyroid protection whenever it can be provided without compromising the diagnostic quality of the dental scan.

You have a valid and reasonable basis to request extra protection, as long as it does not compromise the scan.

Practical options you can take are:

1. Have an open medical discussion.

Discuss your history directly with:

• The oral surgeon and the radiology technician.

Explain your prior thyroid damage and your desire to minimize exposure. Ask:

• Which scans truly cannot be done with a shield?

• Which ones can safely use it?

2. Ask for ALARA measures.

Insist on ALARA (as low as reasonably achievable) principles:

• Only essential scans.

• Small field of view (FOV) on CBCT.

• Low-dose protocols.

• Rectangular collimation for intraoral X-rays.

• Avoid repeat scans unless absolutely necessary.

3. Use a personal thyroid collar.

• You can purchase your own well-fitted lead thyroid collar.

• Bring it with you and request its use when feasible.

4. Ask about modified collars.

Some centers use:

• Low-profile thyroid collars.

• Collars are placed lower on the neck.

These may protect the thyroid without entering the useful beam (especially for certain CBCT protocols).

5. Consider a specialist imaging center.

If you remain uncomfortable:

• Get the scan done at a dedicated dental radiology center or hospital.

• A dentomaxillofacial radiologist or medical physicist can tailor the protocol for you.

6. Involve your endocrinologist.

Ask your endocrinologist for a short note documenting:

• Your thyroid history.

• Recommendation for extra shielding where possible.

Clinics often take such cases more seriously with formal documentation.

The dental office’s position is reasonable for certain scans like CBCT and panoramic imaging, but it is not universally applicable to all dental X-rays.

Given your unique thyroid history, you are fully justified in requesting your own thyroid shield, asking that ALARA radiation protocols be followed, and advocating for added protection whenever it does not interfere with diagnostic image quality; you are not being difficult, you are being medically prudent and appropriately proactive about your health.

I hope this helps.

Kindly revert so I can assist you further.

Thank you.