Oral Maxillofacial Radiology
Oral Maxillofacial Radiology (OMR) is a dental specialty that deals with the use of X-rays (radiographic imaging) to diagnose and treat diseases or disorders of the mouth, teeth, face and jaw (the maxillofacial region). OMR utilizes a combination of standard film X-rays, and digital and panoramic X-rays (radiographs providing a panoramic view of upper and lower dental arches and the temporomandibular joints). OMR also involves the use of radiation and radioactive materials to treat diseases of the mouth and jaws.
Types of Oral Maxillofacial Radiography
Oral Maxillofacial Radiology uses advanced imaging technology, such as digital imaging, plain and computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound.
Digital Imaging: Faster and easier than conventional X-rays, dental imaging with digital X-ray sensors provides high-definition, three-dimensional digital images with 90 percent less radiation exposure than conventional film radiography for diagnosing a wide array of conditions. Digital images can be enlarged and enhanced for better diagnostic detail and accuracy.
Plain and Computed Tomography (CT): Plain film (traditional intraoral or panoramic radiographs), which offers two-dimensional images, and computed tomography (CT), which offers three-dimensional images, are used to diagnose and treat conditions such as impacted teeth and temporomandibular joint (TMJ) disorders, and to determine whether adequate bone structure exists for implant placement, as well as precise location of implant placement.
A CT scan also known as computerized axial tomography (CAT) scan is a diagnostic procedure using special X-ray equipment to obtain cross-sectional pictures of bones and soft tissue, including organs, muscles and tumors. The CT computer displays these components as detailed three-dimensional images with minimal distortion. CT provides image information not obtainable with intraoral or panoramic radiography. CT scanning also is highly effective for examining and diagnosing regions requiring possible endodontic therapy. CT scans aid in the diagnosis and surgery (or other treatment method such as radiation therapy) of oral cancers, where effective dosage depends on the tumor's exact density, size and location
In conventional X-rays, internal structures overlap and images often are obstructed. CT scans eliminate overlapping structures, making internal anatomy clearer, so problems and their location are more identifiable. CT scans provide information in seconds and reduce or eliminate the need for exploratory surgery.
The disadvantages of CT scans are use of contrast dye injections and radiation exposure. Contrast materials, also called contrast agents, are dyes introduced into the body to improve pictures of the inside of the body produced by X-rays, CT scans, MRIs and ultrasounds. Contrast materials help distinguish normal from abnormal conditions. However, cone-bean computed tomography (CBCT) systems have been designed for imaging maxillofacial hard tissue and are capable of providing high-resolution images of high-diagnostic quality with short scanning times (10 to 70 seconds). Images can be displayed chair side, and radiation dosages are up to 15 times lower than those of conventional CT scans.
Magnetic Resonance Imaging (MRI): Used to evaluate and treat TMJ, trauma, disease or abnormal conditions like oral cancer, an MRI is a radiology technique that uses magnetism, radio waves and a computer to produce highly detailed images of body structures.
MRI scanning is painless, avoids X-ray radiation exposure, has no known side effects, and provides precise accuracy in detecting structural abnormalities of the joints, soft tissues and bones. Surgery often can be deferred or more accurately directed after an MRI scan. However, MRI scanning is expensive and uses contrast materials, and its closed-in structure may create a claustrophobic sensation for some patients. Additionally, an MRI's powerful magnetic field will pull on metal-containing objects in the body; MRIs are contraindicated for people with pacemakers, metal implants or other foreign metal bodies.
Ultrasound (US): Ultrasound imaging, also known as ultrasound scanning or sonography, obtains images from inside the human body using high frequency sound waves. The sound waves' echoes are recorded and displayed as real-time, visual images. No ionizing radiation is involved in ultrasound imaging. Ultrasound is both sensitive and specific in detecting abnormalities in soft oral tissues, and may be used for interventional radiology procedures. There are no known side effects associated with ultrasound.
Conditions Requiring Oral Maxillofacial Radiology
Your dentist may refer you to an OMR specialist for any of the following reasons:
- Surgical planning for impacted and wisdom teeth, tooth extraction and other types of oral surgery that may require sedation or general anesthesia
- Facial pain (including problems related to TMJ abnormalities and disorders)
- Oral cancer diagnosis/treatment planning
Other OMR services include:
- Evaluating tumors, cysts, developmental abnormalities and trauma in the maxillofacial region
- Evaluating effects of bisphosphonates and osteonecrosis of the jaws
- Planning orthodontic treatment
- Assessing endodontic or failed endodontic lesions
- Evaluating soft tissue calcifications in the head and neck
- Assessing airways and sleep apnea conditions
When to See an Oral Maxillofacial Radiologist (OMR)
When your general dentist determines that further imaging is necessary to diagnose and/or treat oral maxillofacial conditions whether TMJ problems or locating prospective implant sites he or she will refer you to an OMR, a dentist specialized at reading radiographic images. OMRs typically have access to more sophisticated diagnostic tools and can better diagnose your condition and suggest a treatment plan to your general dentist.
Radiology Benefits and Risks
There is no simple or definitive answer to how much radiation is enough or too much. Generally, the frequency of taking radiographs depends on a patient's oral health, age, risk of disease, and signs/symptoms of oral disease. Whereas cells of older patients are less sensitive, the still-developing cells of children and adolescents are at greater risk of negative effects from radiation exposure. Since radiation effects take years to develop, young people have a longer time to experience possible negative effects. However, the radiation doses required to obtain photos of children are much lower than for adults, so the risks from diagnostic radiation may not necessarily be great. Unborn children are at highest risk from radiation. Pregnant women or those who think they may be pregnant should always inform the radiologic team of their condition.
As with other medical procedures, X-rays are safe when used correctly. Properly conducted imaging produces minimal risks and should be performed when clinically necessary. It is important to remember that the amount of radiation used in most examinations is quite small and, in almost all cases, the benefits vastly outweigh risks.
The decision to have OMR is based on the benefit versus the potential risk from radiation. For low-dose examinations usually those involving only films the decision is simple. For higher dose examinations, such as CT scans and those using contrast materials such as iodine, the patient's past history of X-ray exposure and possible allergies should be considered. Iodine may produce side effects such as a warm sensation during the injection, a metallic taste in the mouth and itching, to more serious reactions such as breathing problems and throat swelling.
Radiologic procedures such as CT and MRI are medically prescribed and should only be performed by appropriately trained and certified professionals under medically necessary circumstances. Improperly performed medical imaging procedures may needlessly expose patients to unsafe radiation levels and result in misdiagnosis or non-diagnosis of existing conditions.
If you or any family members have frequent X-ray examinations and changes in healthcare providers, keep detailed and current records of your X-ray history to avoid unnecessary repetition of tests and to help you and your healthcare team make the best-informed and safest decisions regarding diagnosis and treatment.