This is Part I of a three part series on dental and orthodontic x-rays. It is an excerpt from a 2010 lecture given by Dr. Sean K. Carlson at the North East Society of Orthodontists meeting in Montreal, Canada 2010. It covers some basics of x-ray dosimetry as they relate to common dental and orthodontic diagnostic procedures. It also covers the current recommendations by the International Commission on Radiological Protection (ICRP). To ensure patient protection, the risks associated with dental x-rays should be minimized by all practitioners. This Podcast describes the risk relationships between everyday background radiation exposure, radiation exposure of common events like air travel, and radiation exposure from dental and orthodontic x-ray imaging (including 3-D CBCT x-rays). Viewers will be relieved to learn that radiation exposure in the dental office is minimal when compared with the common things we do everyday.