A cephalometric x-ray, also simply known as a ceph, is a diagnostic radiograph used primarily for orthodontic treatment planning, and is taken during the orthodontic records appointment. Cephalometric x-rays are also used by otolaryngologists -- doctors who specialize in the treatment of ear, nose and throat (ENT) disorders such as sleep apnea -- because these x-rays provide a view of the patient's airways.
Taking a cephalometric x-ray is very similar to having a panorex x-ray taken.
Concentrating on the patient's profile -- or side view of the head -- the x-ray technician positions the patient according to specific criteria necessary when taking a cephalometric x-ray. The exposure takes approximately 10 seconds and the x-ray is developed in approximately five to six minutes. Most dental offices are equipped with the equipment necessary to take a cephalometric x-ray. Once developed, the dentist will use tracing paper, and "trace the ceph" in order to calculate how the patients jaw and surrounding bone will be affected by orthodontic treatment, along with providing the dentist with a look into the growth pattern of the jaw and teeth.
Cephalometric x-rays may be taken intermediately throughout orthodontic treatment, although most orthodontists will only take a preliminary ceph, then a final ceph when treatment is completed.