Answer to Question #12477 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
I understand that panoramic dental x rays give a very small dose of radiation to the patient. Does the x-ray machine have a predetermined amount of radiation for this type of x ray or does the technician dial in the desired level of radiation? Can a distracted technician accidentally give an inadequate (too little or too much) dose of radiation?
The panoramic x-ray units used today have a predetermined amount of radiation per the patient protocols that are established by manufacturers and subject to strict dosimetry studies.
The standards are based on whether a patient is a child, small adult, medium adult, or large adult. These predetermined parameters decrease the likelihood of accidental errors in exposing patients to too much or too little radiation dose during the radiographic examination. The average dose from a panoramic unit is quite low, as you have stated, and is approximately equal to the dose that one receives just being alive on the earth for a day and a half (Ludlow 2008). Therefore, it would be extremely difficult (if not impossible) for a distracted technician to grossly over- or under-expose a patient to ionizing radiation.
Heidi Kohltfarber, DDS, MS, PhD
Diplomate of the American Board of Oral and Maxillofacial Radiography
Ludlow JB, Davies-Ludlow LE, White SC. Patient risk related to common dental radiographic examinations. J Am Dent Assoc 139:1237–1240; 2008.