What is Pediatric Dental Radiology?
There are many different types of x-ray images (pictures) that can be taken of children in the dental office to assist in diagnosis. These include the panoramic and orthodontic (cephalometric) extraoral images, intraoral images such as bitewings and periapicals (little films that go inside the mouth) and cone beam computed tomography (CBCT). All of these dental images use ionizing radiation (x-rays), and therefore parents may be concerned about the increased cancer risk (because of the x-rays) to their children. The following provides information on the risks of dental images in relation to their benefits.
What is X-ray?
X-rays are invisible beams of ionizing radiation. X-rays that are directed to the body do not pass through without changes but are absorbed differently by various tissues of the body. Once they pass through a body part, they are captured by the film and produce images in tones of gray showing calcified stuctures such as the jaw bones, teeth, and other bony structures. The use of x-rays to create dental images is not painful but during the procedure, the child must stay still or else the image may be fuzzy. In some circumstances, parents may be asked to help keep their children still while dental images are taken. Depending on the area of the jaw imaged and the type of dental image, a lead body apron or thyroid shield may be used to reduce radiation exposure to other body areas not being imaged.
What is a panoramic film?
Panoramic films belong to the extraoral category of dental x-rays because the film is outside the mouth. The panoramic film provides to the dentist a good view of the maxilla and mandible as well as the whole dentition. Panoramic films also provide a partial view of the temporo-mandibular joint. One of the major advantages of the panoramic films is the short time required to acquire the image. Panoramic films are widely used by dentist because it provides a comprehensive “panoramic” view of the maxilla and mandible. It is commonly used for evaluation of the wisdom teeth or for the evaluation of potential fractures in trauma cases.
What is a periapical film?
Periapical films belong to the intraoral category of dental x-rays because the film is inside the mouth. The name “periapical “means that this film is designed to evaluate the root and crown of the teeth. The dentist usually takes periapicals of the back and anterior teeth.
What is a bitewing film?
The name “bitewing” refers to a little tab of paper or plastic situated in the center of the x-ray film, which when bite on, allows the film to hover so that it captures an even amount of the maxillary and mandibular teeth. Bitewings are designed to evaluate the crowns and the most superior part of the bone around the teeth. They do not provide information of the roots of the teeth. Dentist usually uses bitewings for evaluation of the area in-between teeth looking for caries. [Figure 3] The American Dental Association (ADA) recommends bitewings for children (until the eruption of the first permanent molars) only if the spaces between teeth cannot visualized in the clinical exam. For children with high risk of decay, the recommendation is to take bitewings every 6 to 12 months (if the spaces between teeth cannot be visualized in the clinical exam). For children with low risk of decay, the recommendation is every 12 to 24 months. The clinical judgment of the dentist is at the end, the most important criteria.
What is Cone Beam Computed Tomography (CBCT)?
Over the past 10 years, cone beam computed tomography (CBCT) has become increasingly available for use in dental offices. CBCT produces images similar to computed tomography (CT) used in medicine except taht CBCT may expose a child to less radiation dose. In CBCT an x-ray device rotates around the head to create many individual pictures of the child's jaw and teeth, and these individual images are used to build a virtual three-dimensional (3D) representation (main advantage of CBCT vs. other dental radiographs). This virtual image may contain diagnostically important information that is not present in other dental images such as bitewing or panoramic image. However, taking a CBCT image results in more radiation dose to the child than other commonly used dental images.
For more information, click here to find out more about Dental Radiation or visit the American Academy of Oral and Maxillofacial Radiology website at www.aaomr.org