Techniques and Interpretation of Dental Radiography

Introduction

Radiology is essential for the diagnosis and treatment of dental, oral and maxillofacial pathology. Dental radiographs should be obtained prior to tooth extraction to evaluate alveolar bone health, variations in root anatomy, and to determine the presence of dentoalveolar ankylosis or root replacement resorption that could potentially complicate the extraction procedure. Radiographs are essential when performing endodontic procedures. Most jaw pathology can be satisfactorily assessed with dental film and intraoral imaging techniques. The largest dental film is also utilized to evaluate diseases of the nasal cavity, orbit, zygomatic arch, mandibular ramus, temporomandibular joint (TMJ) and tympanic bulla in cats and small dogs.

Equipment

Dental radiography machines can be portable or wallmounted and have extension arms that allow vertical, horizontal, and rotational movement of the tube head without changing patient position. Exposure time is the only adjustment to be made, depending on patient size and tissue thickness to be imaged. Dental films can also be used with a standard radiography machine using a technique of 100mA, a film focal distance of 12 inches and an exposure time of 1/10 second, with the kVp varying from 60 to 70. Dental radiography films, a chair side film processor and a view box complete the needed equipment. Digital imaging utilizes sensor pads instead of films that transfer the image to a computer. This requires less radiation to produce an image, which may also be enhanced with software programs. Dental radiography film is a non-screen film, which provides greater detail than the screened film typically utilized with standard radiography machines. Ultra-speed (Dfilm) and sizes 0, 2 and 4 are most commonly utilized. The films are within a moisture resistant packet, and there is black paper on either side of the film. A layer of lead foil is located at the back of the packet, protecting the film from secondary radiation. A dimple is located in one corner of the film packet. Its convex (raised) surface must face the radiographic beam during exposure. The dimple is used to distinguish images obtained from the left and right sides of the mouth on the processed radiographs. Dental rapid developer and fixer are utilized for film processing. These solutions are placed in small containers within a chair side film processor (from left to right: developer, water, fixer, and water). Automatic film processors are also available. [...]