There are two main types of dental X-rays: intraoral (meaning the X-ray film
is inside the mouth) and extraoral (meaning the X-ray film is outside the
mouth).
Intraoral X-rays are the most common type of dental X-ray
taken. These X-rays provide a lot of detail and allow your dentist to find
cavities, check the health of the tooth root and bone surrounding the tooth,
check the status of developing teeth, and monitor the general health of your
teeth and jawbone.
Extraoral X-rays show teeth, but their main focus is the
jaw and skull. These X-rays do not provide the detail found with intraoral
X-rays and therefore are not used for detecting cavities or for identifying
problems with individual teeth. Instead, extraoral X-rays are used to look for
impacted teeth, monitor growth and development of the jaws in relation to the
teeth, and to identify potential problems between teeth and jaws and the
temporomandibular joint (TMJ, see document, "Temporomandibular disorders" for more information) or other
bones of the face.
Types of Intraoral X-Rays
There are several types of intraoral X-rays, each of which shows different
aspects of teeth.
Bite-wing X-rays show details of the upper and lower teeth
in one area of the mouth. Each bite-wing shows a tooth from its crown to about
the level of the supporting bone. Bite-wing X-rays are used to detect decay
between teeth and changes in bone density caused by gum disease. They are also
useful in determining the proper fit of a crown (or cast restoration) and the marginal integrity of fillings.
Periapical X-rays show the whole tooth -- from the crown
to beyond the end of the root to where the tooth is anchored in the jaw. Each
periapical X-ray shows this full tooth dimension and includes all the teeth in
one portion of either the upper or lower jaw. Periapical X-rays are used to
detect any abnormalities of the root structure and surrounding bone
structure.
Occlusal X-rays are larger and show full tooth development
and placement. Each X-ray reveals the entire arch of teeth in either the upper
or lower jaw.
Types of Extraoral X-Rays
There are several types of extraoral X-rays that your dentist may wish to
take.
Panoramic X-rays show the entire mouth area -- all the
teeth in both the upper and lower jaws -- on a single X-ray. This type of X-ray
is useful for detecting the position of fully emerged as well as emerging
teeth, can identify impacted teeth and aid in the diagnosis of tumors.
Tomograms show a particular layer or "slice" of
the mouth while blurring out all other layers. This type of X-ray is useful for
examining structures that are difficult to clearly see -- for instance, because
other structures are in very close proximity to the structure to be
viewed.
Cephalometric projections show the entire side of the
head. This type of X-ray is useful for examining the teeth in relation to the
jaw and profile of the individual. Orthodontists use this type of X-ray to
develop their treatment plans.
Sialography involves visualization of the salivary glands
following the injection of a dye. The dye, called a radiopaque contrast agent,
is injected into the salivary glands so that the organ can be seen on the X-ray
film (the organ is a soft tissue that would not otherwise be seen with an
X-ray). Dentists might order this type of test to look for salivary gland
problems, such as blockages or Sjogren's syndrome.
Computed tomography, otherwise known as CT scanning, shows
the body's interior structures as a three-dimensional image. This type of
X-ray, which is performed in a hospital rather than a dentist's office, is used
to identify problems in the bones of the face, such as tumors or
fractures.
Sjögren's syndrome is an autoimmune disease involving the abnormal production of extra antibodies that attack the glands and connective tissue. Sjögren's syndrome with gland inflammation (resulting dry eyes and mouth, etc.) that is not associated with another connective tissue disease is referred to as primary Sjögren's syndrome. Sjögren's syndrome that is also associated with a connective tissue disease, such as rheumatoid arthritis, systemic lupus erythematosus, or scleroderma, is referred to as secondary Sjögren's syndrome. Though there is no cure for Sjögren's syndrome, the symptoms may be treated by using lubricating eye ointments, drinking plenty of water, humidifying the air, and using glycerin swabs. Medications are also available to treat dry eye and dry mouth.
Temporomandibular joint disorder, or TMJ, is a disorder of the temporomandibular joint(s) that causes signs and symptoms including ear pain, bite problems, headaches, dizziness, clicking sounds in the jaw, tinnitus and/or locked jaws. Behaviors or conditions that can lead to TMJ include teeth grinding or clenching, fingernail biting, habitual gum chewing, trauma to the jaw, stress, and occupational hazards. Treatment for TMJ may include heat, ice, a soft diet, antiinflammatory medications, physical therapy, stress management, occlusal therapy, correction of bite abnormalities, and surgery.
The term oral cancer includes cancer of the mouth (oral cavity) and the back of the mouth (oropharynx). Red and white patches inside the mouth, bleeding, loose teeth, pain upon swallowing, a lump in the neck, earache, and a sore on your lip or in your mouth that won't heal are all symptoms of oral cancer. Treatment for oral cancer depends upon the staging of the disease and usually involves surgery, radiation therapy, or chemotherapy.
Toothache usually refers to pain around the teeth or jaws. In most instances, toothaches are caused by tooth or jaw problems, such as a dental cavity, a cracked tooth, an exposed tooth root, gum disease, disease of the jaw joint (TMJ), or spasms of the muscles used for chewing. A toothache can also be caused by a problem that does not originate from a tooth or the jaw, like diseases of the heart (angina or heart attack), ear infections, and sinus infections. A thorough oral examination, which includes dental X-rays, can help determine the cause.
Gum disease is caused by plaque and may result in tooth loss without proper treatment. Symptoms and signs of gum disease (gingivitis or periodontal disease) include receding gums, bad breath and pocket formation between the teeth and gums. Treatment depends upon the stage of the gum disease, how you responded to earlier treatments, and your overall health.
Dental injuries range from a chipped or fractured tooth to a knocked out tooth. Treatment depends upon the severity of the dental injury. Dental injuries may be prevented by aligning protruding front teeth with braces and using face masks and mouthguards while playing sports.
Learn more about what cavities like, their symptoms, treatment and prevention. See how tooth decay, plaque and bacteria contribute to the creation of cavities and how regular brushing and flossing can help.
Many people think cavities only affect children, but changes that occur with
aging make cavities an adult problem too. Recession of the gums (a pulling away
of gum tissue from the teeth), often associated with an increased incidence of
gingivitis (gum disease), can expose tooth roots to plaque. Also, sugary
food cravings in pregnant women can make them more vulnerable to developing
cavities.
Decay around the edges of cavity fillings is also common in older adults. Because
many older adults lacked the benefits of fluoride and modern preventive dental
care when they were growing up, they often have a number of dental fillings.
Over the years, these fillings may weaken and can fracture, allowing bacteria
to accumulate in the tiny crevices causing tooth decay.
How Do I Know if I Have a Cavity?
Your dentist can discover cavities during your regular dental check-up. The
tooth surface feels soft when probed ...