If your toddler is able to follow simple instructions, then your pediatric dentist may use Occlusal X-rays to help in evaluating the presence and position of developing permanent teeth beneath the primary teeth. This type of dental X-ray is the most common for children around the age of 2 – 3 years as it can help to identify any dental or oral issues that your child is at risk of, at this very young age.
X-rays refer to the invisible beans of ionizing radiation that pass through a body part and are captured by a film on the other side, producing images in different tones of grey that show calcified structures such as teeth, jaw bones, and other bone structures.
But what exactly are the risks of dental x-rays compared to their benefits?
X-rays are a vital tool for dentists to help them identify signs of dental disease or possible problems that cannot be detected with the naked eye. They are typically ordered after the dentist has done a thorough clinical exam, and considered oral and medical history, any signs and symptoms, fluoride use, hygiene, diet, and other factors that may indicate the possibility of hidden dental disease, and then concluded that an x-ray is important to make proper diagnosis.
Types of X-rays for children
There are different types of dental x-rays that can be taken to assist in diagnosis, including:
- Intraoral images such as bitewings and periaicals;
- Panoramic and orthodontic extraoral images;
- Cone beam computed tomography (CBCT).
None of these x-rays are painful, but they all use ionizing radiation (x-rays) that many parents are concerned will increase the risk of cancer and health conditions to their children. This issue arises when x-rays directed to the body fail to pass through without causing any changes, and are instead absorbed by the various body tissues.
Pediatric dental x ray guidelines
Radiographs are valuable diagnostic aids in the oral examination of infants, children, adolescents, and individuals with special health care needs.
They are used to:
- Diagnose and monitor oral diseases
- Evaluate dentoalveolar trauma,
- Monitor dentofacial development and the progress of therapy
In many cases the radiographic findings add important information. However, the risks associated with radiography should not be neglected. Guidelines in dental radiology are designed to avoid unnecessary exposure to X-radiation and to identify those individuals who may benefit from a radiographic examination.
According to the recommendations in the ADA/FDA guidelines, radiographs should be taken to substantiate a clinical diagnosis and guide the practitioner in making an informed decision that will affect patient care.
The AAPD (American Academy of Pediatric Dentistry) recognizes that there may be clinical circumstances for which a radiograph is indicated, but a diagnostic image cannot be obtained. When diagnostic radiographs cannot be obtained due to a lack of cooperation, technical issues, or a health care facility lacking in intraoral radiographic capabilities, the practitioner should inform the patient or guardian of these limitations and document these discussions in the patient’s record. The decision to treat the patient without radiographs will depend upon:
- The urgency of the treatment needs
- Availability and appropriateness of alternative treatment settings, and
- Relative risks and benefits of the various treatment options for the patient
Occlusal X-rays for children aged 3 years
Occlusal X-rays can be safely used on children aged around 3 years to help identify any anomalies such as extra teeth or a missing tooth in a specific area. They are taken only once.
Bitewing X-rays for children aged 4 and 5 years
When your child reaches the age of 4 – 5 years, your pediatric dentist may start using bitewing X-rays to help detect cavities at the earliest stage possible for timely intervention. At this age, the back molars are beginning to touch each other. This, combined with the fact that children have a high affinity for sweets and poor brushing skills, increases their risk of cavities. Bitewing X-rays can be used to capture images on both the left and right side to show presence of cavities. Children at high risk of cavities can safely get the X-rays every 6-12 months, but those who are not can wait a bit longer, at 12 – 24 months.
Panoramix X-rays for 6-year old children with permanent teeth
These X-rays are able to capture all the jaws and teeth in a single image, using a machine that covers your child’s entire head. These X-rays become necessary when permanent teeth begin to emerge, which is around the age of 6-years, to assess their development under the primary teeth. They can help to identify congenitally missing teeth, extra teeth, and oral pathologies such as cysts and tumors. They can be safely performed every 5 years to check for any developmental anomalies as well as oral pathologies.
Periapical X-rays
This is a single image capture that reveals a specific target area of concern that needs to be assessed. Although Bitewing Xrays are a great choice for identifying the presence and size of cavities, they cannot show any existing or possible infections. As such, pediatric dentists may recommend Periapical Xrays to get a glimpse of the root area, where infections typically show up, following trauma or a case of large cavities that need to be checked for infection. So Periapical X-rays are generally done on an as-needed basis.
Selection Criteria for prescription of dental radiographs
Based on objective findings/symptoms
- Caries
- Traumatic injuries
- Problems of eruption
- Developmental anomalies
- Evaluation of growth abnormalities
- Unexplained teeth discoloration
- Unusual tooth morphology, calcification or color
- Unexplained teeth sensitivity
- Unusual teeth spacing or migration
- Unexplained tooth mobility
- Orthodontic treatment planning and evaluation
- Pulpal and periapical pathology
- Unexplained bleeding
- Lack of response to conventional dental treatment
- Aid in diagnosis of systemic disease
- Postoperative evaluation
How much radiation is the child exposed to?
Every day, all creation is exposed to minute amounts of radiation from the environment. This radiation comes from the ground, outer space, air, water, and even building materials, and is referred to as natural background radiation. Different people are exposed to different amounts of this radiation depending on where they live. For instance, people who live at higher altitude are exposed to more radiation compared to those living at sea level.
Researches on dental radiation risks, comparing radiation doses from dental images to equivalent amounts of natural background radiation, do not show any conclusive evidence that radiation from diagnostic dental x-rays causes’ cancer, but they also claim that 1 in every 1,000 individuals develop cancer when exposed to 10mSv.
However, major national and international organizations involved in the evaluation of x-ray risks agree that any amount of exposure to radiation should be minimized as much as possible. This is particularly important for children because they are 3-5 times more likely to suffer side effects of radiation compared to adults, because their developing tissues are more radiosensitive, and have a longer period within which any radiation-induced cancer could develop.
How dentists reduce exposure to radiation
Because the effects of radiation exposure accumulate over time, every effort must be made to minimize the patient’s exposure. Good radiological practices are important in minimizing or eliminating unnecessary radiation in diagnostic dental imaging.
To reduce the amount of x-ray radiation used to create a dental image, dentists usually adjust the settings on the x-ray device to suit the child’s size. The effective radiation dose to the body is measured by millisievert (mSv). In addition, depending on the type of dental image and area of the jaw being imaged, a thyroid shield or lead body apron may be used to minimize radiation exposure to other areas of the body not being imaged.
Examples of good radiologic practice include:
- Use of the fastest image receptor compatible with the diagnostic task
- Collimation of the beam to the size of the receptor whenever feasible
- Proper film exposure and processing techniques
- Use of protective aprons and thyroid collars
- Limiting the number of images to the minimum necessary to obtain essential diagnostic information.
The dentist must weigh the benefits of obtaining radiographs against the patient’s risk of radiation exposure. Considering the cumulative effect of ionizing radiation, and that children are more prone to radiation induced carcinogenesis than adults, the clinician needs to be aware of the inherent risks associated with cone beam tomography and the as low as reasonably achievable (ALARA) principle in patient selection. The American Academy of Oral and Maxillofacial Radiology (AAOMR) has published position statements which summarize the potential benefits and risks of maxillofacial CBCT use in orthodontic and endodontic diagnosis, treatment, and outcomes and provides clinical guidance to dental practitioners.
References
https://www.aapd.org/media/Policies_Guidelines/BP_Radiographs.pdf
https://www.aapd.org/assets/1/7/E_Radiographs1.PDF
https://www.fda.gov/consumers/consumer-updates/dose-matters-fdas-guidance-childrens-x-rays
