1. Basic principles of dental radiology

The facial mass is essentially made up of bone, teeth (including enamel and dentine) and supporting soft tissues. Dental radiology is therefore essentially the imaging of mineralized tissues, exploiting the absorption properties ("true" absorption by the photoelectric effect and mainly Compton attenuation) of medium-energy X-rays transmitted [MED 100] . Today, the X-ray source is always placed outside the oral cavity, with the sensor inside the mouth (intra-oral or intra-buccal techniques) or outside the mouth (extra-oral or extra-buccal techniques).