This is the abbreviation for a Cephalogram which is a side-view X-ray of the skull. Unfortunately, this is usually described as a ‘lateral tele-radiograph’ in German (FRS), which is not really understood on the international front. [See lateral tele-radiograph’ (FRS)]. The Ceph was hugely important in studying the growth of the face and the skull and also the therapeutic effects of orthodontic appliances. This also explains why it plays such an important role in orthodontic training because it enables prospective orthodontists to check the results of their treatment. But, for experienced orthodontists the Ceph is usually of little significance and should be dispensed with completely, if only to protect patients against radiation. Unfortunately, although it makes no sense, it is still usual in many places to do a Ceph for any kind of treatment – even the simplest of procedures. But collecting endless data should not be confused with prudence: the only really interesting data is information that can influence therapeutic decisions. However, this is usually not the case for cephs, as could be demonstrated in scientific studies.