Dose reduction to the thyroid gland in intraoral source radiography

Organs near the oral cavity may be exposed to unacceptably high levels of radiation in intraoral source radiography. Three methods for reducing the dose to the thyroid gland have been investigated. A restriction of the exposure geometry by use of the B and C types of applicator was an efficient means of dose reduction. Absorbed doses to the thyroid gland were 30-50% less than those obtained when using the A-type applicator. A 10 degree upward inclination of the occlusal plane reduced the dose by 20%. In contrast, three thyroid protectors had no effect on dose reduction.