1. An extra-oral dental X-ray imaging system comprising: an X-ray source adapted for generating x-rays for exposure of such x-rays to an object to be imaged; an X-ray imaging device adapted for producing multiple frames during at least part of the exposure; at least one rotational axis around which at least one of the X-ray source and imaging device rotates along a spline, the axis being located between the X-ray source focal point and the X-ray imaging device; and a fast memory having an access and storage speed comparable to a readout speed of the X-ray imaging device, the memory storing and holding substantially all the frames produced, and the stored and held frames being individually selectively accessible.