This is Part III of a podcast series on dental and orthodontic x-rays. This provides an update of the information covered in Part I and Part II. It reviews x-ray dosimetry, which is the calculation of the absorbed dose in human tissue resulting from the exposure to ionizing x-ray radiation. Dosimetry can be a confusing subject for even the savviest of orthodontists. Unknown to many, recent advances in CBCT technology have reduced x-ray exposure to patients considerably. And although there is a common misconception that CBCT imaging dramatically increases the exposure risk when compared to conventional two-dimensional orthodontic imaging, recent data shows there is minimal difference. In fact, when the truth about risk quantification is added to the equation, both orthodontists and dentists alike should be put at ease when it comes to their exposure liability.