Most people know that x-rays are used to take pictures of the jaw bone and teeth, but few know that x-rays also enable dentists to examine for diseases such as oral cancers, sinus infections, gum diseases, and jaw joint pain. Many diseases that would go undetected for a long period of time through visual examination can be caught at an early treatable stage through x-rays. Radiographs (x-rays) are a vital and necessary part of the dental diagnostic process. Due to early detection, many diseases are treated without the need for drastic treatments, such as roots canals or extractions.

Without xrays, certain conditions can and will be missed. The exposure from dental radiographs is extremely small, especially with new advancements in film speed and processing.

Bitewing radiographs are the radiographs taken most frequently. These are the ones where you close your mouth and bite on a tab. Bitewing radiographs are important for detecting decay in between the teeth and for evaluating the periodontal condition.

Xrays provide a good view of the bone level. Changes in bone height can also be detected with bitewing radiographs. Bitewings can also be quite useful for detecting calculus (or tartar) between the teeth. This information can help the dentist or hygienist clean the teeth properly.

This is what Dr. Bob saw in the mouth. The cavities between these teeth were undetectable on clinical examination.

This is part of a bitewing x-ray taken of the two teeth seen in the above photo. This type of x-ray is commonly taken for diagnosis of cavities. The cavities that you can see in the xray were not visible clinically, and they are, as you can see, quite deep. The pulp chamber is where the nerve of the tooth is.

Periapical radiographs show the entire tooth from the crown to the end of the root. This type of film will show any root anomalies, changes in the bone surrounding the root, cysts, abscesses, etc. The fine detail obtained in these films can be extremely important and helpful in diagnosis.

Full mouth series radiographs are a series of 16-18 periapical radiographs taken at the same time, of all of the teeth, so that bone levels, periapical problems, and periodontal (problems with the gums and supporting bone), tartar levels, and caries can be evaluated. The advantage of full mouth radiographs is the fine detail that can be seen on each tooth and tooth root. The disadvantage is that problems deeper than the end of the tooth root cannot be seen.

This is a full mouth series of x-rays. This is sometimes taken instead of a panorex to see greater detail of the teeth only.

Panoramic radiographs are the ones where you stand or sit and the x-ray machine moves around your head. With panoramic x-rays, a broad area is imaged, exposure level is relatively low (about the same as 4 bitewing radiographs), and they are convenient. The disadvantage is that the image does not provide the fine detail that bitewings and periapical radiographs provide. Panoramic radiographs are excellent for evaluation of trauma, third molars, tooth development, and certain anomalies. They also will give a good impression of the overall bone levels and sinus position. They are not good for diagnosing decay and certain types of periapical problems.

This is a panorex radiograph. The dentist can see all of the teeth, the sinuses, bone levels, as well as any abnormal pathology. As you can see, the roots are not totally covered by bone. The teeth of this patient are loose. This is an example of the destructive nature of periodontal(gum) disease.

Cephalometric radiographs are used for diagnosing and treatment planning in orthodontic cases. Many measurements are taken, giving the treating dentist information about growth patterns, relative position of the upper and lower jaw to the cranium (skull) and to each other. Cephalometric radiographs also give the treating dentist a good indication of the presence of airway problems (shows the size and position of tonsils and adenoids).

The American Dental Association has recommended that the type and frequency of dental radiographic examination be based upon clinical judgement after examination and consideration of the dental and general health of the patient. There are, however, some basic guidelines dentists follow. On average, dentists do request bitewing radiographs approximately once a year. This is mainly to detect and treat conditions early before they become a major problem. If a patient has a healthy mouth and does not appear to be cavity prone, I might take bitewings every 18 to 24 months. If a patient has a serious cavity problem, I will take bitewings every six months until I am certain that the problem is under control. Approximately, every 5-7 years, it is generally a good idea to obtain a full mouth series of radiographs (or a panoramic radiograph) and bitewings. Occasionally, conditions can develop "quietly," and obtaining these films will help dentists determine if any developments have taken place. Again, while I do understand certain concerns from patients, these radiographs are invaluable for diagnosing conditions and obtaining and maintaining oral health.

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