As defined by the ADA, Oral and Maxillofacial Radiology is the specialty of dentistry and discipline of radiology concerned with production and interpretation of images and date produced by all modalities of radiant energy that are used for the diagnosis and management of diseases, disorders and conditions of the oral and maxillofacial region.
Using an x-ray machine to take radiographs is an every day part of dentistry and is an invaluable tool in the diagnosis of oral disease. Most dentists have an x-ray machine in each operatory of the office in addition to a panoramic x-ray machine. Standard radiographs include the bitewing images that capture both the upper and lower teeth together and are used to identify cavities, especially interproximal (between teeth) cavities, and the periapical radiographs that capture the full crown and root of the tooth that are used to diagnose problems along or around the root. Panoramic radiographs are taken less frequently and are used to watch developing teeth, especially third molars, and to identify any pathology in the maxilla, mandible or associated structures.
A molar bitewing and a molar periapical radiograph
Some highly equipped offices, like those of oral surgeons, may have more advanced imaging technologies they use like computed tomography (CT), cone beam computed tomography (CBCT), and magnetic resonance imaging (MRI).
Oral radiologists are the experts in using all of these various imaging technologies and interpreting the images. These experts may be called on by general dentists or other dentists to get help with diagnosing or treatment planning from complex cases like those involving TMJ issues, oral pathologies, surgical implants, or orthodontics. Some oral radiologists may have private practices, although most are affiliated with hospitals, dental schools, and research institutions.
Ameloblastoma developing in the mandibular third molar region
The residency for oral and maxillofacial radiology lasts 2 to 3 years following the completion of a DDS or DMD degree. During residency training, prospective oral radiologists will have extensive experience in medical diagnostic radiology, nuclear medicine, radiation oncology, radiation biology, swallowing physiology, radiation physics, radiation biology, radiation risk and safety, and imaging technology including CT, CBCT, MRI and allied imaging modalities. This specialty field is fairly small with only a handful of residency programs and small numbers of applicants compared to other dental specialties. You can find a list of oral radiology residency programs at the American Academy of Oral and Maxillofacial Radiology. The AAOMR also has some additional information about education and careers in oral and maxillofacial radiology.