Dental Cone-beam Computed Tomography

Description

Cone-beam computed tomography systems (CBCT) are a variation of traditional computed tomography (CT)systems. The CBCT systems used by dental professionals rotate around the patient, capturing data using a cone-shaped X-ray beam. These data are used to reconstruct a three-dimensional (3D) image of the following regions of the patient’s anatomy: dental (teeth); oral and maxillofacial region (mouth, jaw, and neck); and ears, nose, and throat (“ENT”).

Uses

Dental CBCT systems  are increasingly used by radiologists and dental professionals for various clinical applications including dental implant planning, visualization of abnormal teeth, evaluation of the jaws and face, cleft palate assessment, diagnosis of dental caries (cavities), endodontic (root canal) diagnosis, and diagnosis of dental trauma.

Benefits/Risks

X-ray imaging, including dental CBCT, provides a fast, non-invasive way of answering a number of clinical questions. Dental CBCT images provide three-dimensional (3-D) information, rather than the two-dimensional (2-D) information provided by a conventional X-ray image. This may help with the diagnosis, treatment planning and evaluation of certain conditions.

Although the radiation doses from dental CBCT exams are generally lower than other CT exams, dental CBCT exams typically deliver more radiation than conventional dental X-ray exams. Concerns about radiation exposure are greater for younger patients because they are more sensitive to radiation (i.e., estimates of their lifetime risk for cancer incidence and mortality per unit dose of ionizing radiation are higher) and they have a longer lifetime for ill effects to develop.

 

Information for Patients and Parents

The American Dental Association (ADA) and the FDA recommends that clinicians perform dental X-ray examinations, including dental CBCT, only when necessary for the diagnosis or treatment of disease. The clinical benefit of a medically appropriate X-ray imaging exam outweighs the small radiation risk. However, efforts should be made to help minimize this risk.

The FDA also recommends that for all X-ray imaging procedures, including dental CBCT, patients and parents of children should:

·         Talk with their health care provider.

ü  Review the benefits and risks of the procedure before it is performed.

ü  Discuss if the imaging exam is necessary and if there are equally useful alternative exams that use no or less ionizing radiation.

ü  Ask if the facility uses radiation reduction techniques such as size-based protocols for children.

Information for Dental Professionals

Dental CBCT should be performed only when necessary to provide clinical information that cannot be provided using other imaging modalities.

Imaging professionals should follow the principles of justification and optimization in the protection of patients undergoing radiological examinations. The FDA recommends that dental professionals:

·         Discuss the rationale for the examination with the patient and/or parent to ensure a clear understanding of benefits and risks.

·         Reduce the number of inappropriate referrals (i.e., justify X-ray imaging exams) by:

ü  Determining if the examination is needed to answer a clinical question,

ü  Considering alternate exams that use less or no radiation exposure, and

ü  Reviewing the patient's medical imaging history to avoid duplicate exams.

·         Use exposure settings for dental CBCT exams that are optimized to provide the lowest radiation dose that yields an image quality adequate for diagnosis (i.e., radiation doses should be "As Low as Reasonably Achievable"). The technique factors used should be chosen based on the clinical indication, patient size, and anatomical area scanned, and the equipment should be properly maintained and tested.

Information for Industry

Dental CBCT systems are medical devices that are also radiation-emitting electronic products. The FDA regulates manufacturers of dental CBCT devices through the Electronic Product Radiation Control (EPRC)and medical device provisions of the Federal Food, Drug, and Cosmetic Act. Dental CBCT systems are classified under 21 CFR 892.1750.