When is a thyroid collar recommended?

• A. Never use it
• B. Only for panographic radiographs
• C. It should be used on all radiographs
• D. For most intraoral radiographs, provided it does not obscure diagnostic information

Answer: (D)

Thyroid shielding helps limit radiation to the thyroid gland, which is particularly sensitive to ionizing radiation. For intraoral radiographs, a thyroid collar is recommended in most cases because it can be worn around the neck without interfering with the imaging of the teeth, provided it does not obscure the region of diagnostic interest. When placed correctly, the collar reduces scatter reaching the thyroid while preserving image quality. If placing the collar would cover part of the area being imaged or degrade diagnostic information, it should be removed for that exposure and other protection strategies used instead.