IEC 60601-2-63:2012 applies to the basic safety and essential performance of dental extra-oral X-ray equipment, hereafter also called ME equipment. The scope includes ME systems containing such ME equipment. This particular standard has been prepared to provide, based on IEC 60601-1:2005 and its collaterals, a complete set of basic safety and essential performance requirements for dental extra-oral x-ray equipment. While the previously existing standards for such equipment were dedicated to components and subsystems, this particular standard addresses the system level of dental extra-oral x-ray equipment. Components and their functions are addressed as far as necessary. The scope of this standard is restricted to X-ray equipment where: - the x-ray tube assembly contains the high-voltage transformer assembly; and - the geometrical relations between the X-ray source, the anatomical object being imaged in the patient, and the X-ray image receptor, are preset in the design and cannot be arbitrarily altered by the operator during intended use.