Paediatric Dental Imaging: Balancing Diagnostic Need and Radiation in Children
There's a particular kind of worry that only parents know. It's the one that arrives in the waiting room of a dental clinic when the dentist says, "We should get an X-ray," and your child is six years old. You want to ask whether it's really necessary. You want to know how much radiation that is. You want to know if it's safe.
Those are exactly the right questions to ask. And as a maxillofacial radiologist who has worked with paediatric cases for nearly two decades, I want to give you — and the dental professionals who refer these cases — a clear, honest, clinically grounded answer.
Children are not simply small adults when it comes to radiation. Their biology is different. Their risk profile is different. And the way we approach imaging for them should reflect that — with protocols that are more conservative, more carefully justified, and more precisely calibrated than what we'd use for a 45-year-old. That's not a reason to avoid imaging when it's needed. It's a reason to do it properly.
Why Children Require a Different Approach to Dental X-Rays
The sensitivity of human tissue to ionising radiation is not fixed. It varies by age, by organ, and by the rate at which cells are dividing. In children, all three of those variables shift the equation:
Rapidly dividing cells are more sensitive to radiation. A child's body is in a state of active growth — bones are lengthening, tissues are developing, dental roots are forming. Dividing cells have less time to repair any radiation-induced DNA damage before replication, which is why developing tissue carries a higher relative sensitivity than mature adult tissue.
Longer life expectancy ahead. Radiation risk models work over a lifetime. A 7-year-old has many more years ahead in which any very small increased risk of radiation-induced effects could theoretically manifest, compared to a 55-year-old receiving the same dose.
Smaller body size. A child's head is smaller, which means the same X-ray beam covers a proportionally larger area of their body if collimation isn't adjusted appropriately. Proper child-specific settings are not optional — they're a clinical necessity.
None of this means dental X-rays for children are dangerous. It means they demand a higher level of justification, more careful technique, and a consistent application of the principles that govern good radiation practice — particularly ALADA, which we'll come to shortly.
ALADA — The Principle That Should Govern Every Paediatric X-Ray
You may have heard of ALARA — As Low As Reasonably Achievable. In paediatric dental imaging, this principle is extended to ALADA: As Low As Diagnostically Acceptable.
The distinction matters. ALARA tells us to minimise dose. ALADA goes a step further and says: minimise dose to the lowest level at which the image still provides what the clinician needs to make the right diagnostic decision. In children, where we are most conservative about exposure, this refinement is meaningful.
In practical terms, ALADA means:
Every X-ray must have a clear clinical reason before exposure — not "we usually take these" or "it's been a year since the last set." A specific diagnostic question must exist.
The smallest number of images that answer that question should be taken.
The lowest dose settings that still produce a diagnostically adequate image should always be used — and for children, these settings are different from adult defaults.
Protective equipment — thyroid collar and lead apron — must be used for every paediatric dental X-ray without exception.
Existing X-rays from previous appointments or referring practices should be reviewed before new ones are taken. Repeat exposure because records weren't transferred is not acceptable.
📌 For paediatric dentists:
ALADA is not a compromise on diagnostic quality — it is a higher standard of clinical decision-making. If an image taken at reduced settings still answers your clinical question with confidence, that is the correct image to take.
Age-Appropriate Imaging Protocols — What Should Actually Be Taken and When
There is no single correct answer to "how often should my child have dental X-rays?" — because the answer depends entirely on the individual child's caries risk, clinical presentation, and what the dentist actually needs to know. What exists are evidence-based guidelines that help calibrate that decision.
Under 5 years
Routine dental X-rays are rarely indicated in this age group. Periapical X-rays may be taken if there is clinical suspicion of abscess, infection, or trauma affecting a primary tooth's root. The dose involved is very small, but the clinical justification must be present.
5–10 years (mixed dentition)
Bitewing X-rays are the most common and appropriate modality in this group. They allow assessment of interproximal cavities — the decay between teeth that a visual examination cannot detect. For a child at average caries risk, bitewing radiographs every 12–18 months is a reasonable interval. For a high-risk child with active decay, more frequent monitoring may be justified. For a low-risk child with excellent hygiene and no clinical concerns, stretching to 24 months is reasonable.
10+ years (adolescent, approaching permanent dentition)
This is where OPG (panoramic X-ray) becomes relevant — particularly for orthodontic assessment, evaluating permanent tooth development, and monitoring wisdom tooth formation. An OPG at an appropriate clinical juncture delivers a very low effective dose (approximately 0.01–0.026 mSv on modern digital equipment) and provides information across the full arch that individual films cannot match efficiently.
📋 Guiding question for every paediatric imaging decision:
What specific clinical question am I trying to answer, and is this the minimum imaging required to answer it reliably? If that question can't be answered clearly before the exposure is made, the exposure should wait.
CBCT in Children — When Is It Justified, and How Should It Be Done
Cone Beam CT in paediatric patients is a topic where I want to be very direct: CBCT should only be used in children when conventional 2D imaging genuinely cannot answer the clinical question. It is not a first-line investigation. It is not a default for orthodontic planning. It is a specific tool for specific indications where the additional diagnostic information it provides demonstrably changes clinical management.
Appropriate paediatric CBCT indications
Assessment of unerupted, impacted, or supernumerary teeth where 2D imaging is insufficient to determine position, angulation, or proximity to adjacent structures
Evaluation of jaw pathology — cysts, tumours, or bony lesions — where 3D anatomy is essential
Craniofacial anomalies and syndromic conditions requiring surgical planning
Dentoalveolar trauma with suspected root fractures or displacement that cannot be adequately assessed on periapical films
Specific airway assessment for obstructive sleep-disordered breathing evaluation in selected cases
What "child-specific CBCT settings" actually means
The most important dose variable in CBCT is the field of view (FOV). In children, the smallest FOV that covers the anatomical area of interest must always be selected. A full-head large FOV scan — which might be acceptable for a complex adult orthognathic surgery case — is rarely justified in a child. A small or medium FOV covering the specific area of concern is the appropriate choice in almost all paediatric cases.
Beyond FOV, modern CBCT machines have dedicated paediatric protocols that reduce milliampere settings and rotation arc. These settings can reduce effective dose by 40–60% compared to standard adult protocols, with minimal impact on diagnostic quality for the specific images being assessed. Any imaging centre performing CBCT on children should have these protocols configured and should be using them as standard — not as an optional selection.
Typical effective dose for a small-FOV paediatric CBCT with optimised settings: 0.05–0.15 mSv. Compare this to a medical CT of the head: approximately 1–2 mSv. CBCT, when used correctly, is still a relatively low-dose investigation — but it must be used correctly.
Protective Measures That Are Non-Negotiable for Children
For every dental X-ray taken in a child — from a single bitewing to a full OPG — the following should be standard, not optional:
Thyroid collar: The thyroid gland is among the most radiosensitive organs, and children's thyroid glands are particularly so. A properly fitted thyroid collar should be worn for all paediatric dental X-rays where it does not interfere with the diagnostic area.
Lead apron: Protects the chest and reproductive organs from scattered radiation. Should be used routinely for children.
Digital imaging over film: Digital sensors require significantly less radiation to produce an adequate image compared to conventional film — dose reductions of 50–80% are achievable. In 2026, there is no clinical justification for using conventional film for paediatric dental imaging if digital equipment is available.
Proper collimation: The X-ray beam should be collimated tightly to the area of interest. Rectangular collimation for intraoral films reduces dose compared to round collimation. In children, whose faces are smaller, this matters proportionally more.
What Parents Should Ask — and What the Answers Should Sound Like
If your child's dentist recommends an X-ray, these are the questions worth asking. A good dental team will not only answer them — they'll welcome them.
What specifically are you looking for with this X-ray? — There should be a clear, clinical answer. "Routine" or "we always take them" is not a sufficient reason.
Is this the smallest number of images needed? — The dentist should be able to confirm they've selected the minimum imaging necessary.
Will my child have a thyroid collar and lead apron? — The answer should always be yes.
Does this facility use digital X-ray equipment? — Digital is the appropriate standard for children.
My child had X-rays at their previous dentist 6 months ago — can we use those? — If those records are transferable and still clinically relevant, a good practice will ask for them before repeating exposure.
The anxiety a parent feels about dental X-rays for their child is completely understandable — and it's a useful instinct. Channel it into these specific questions rather than a blanket refusal, which can lead to missed diagnoses that have real consequences.
The Bottom Line
Dental X-rays for children are safe when properly indicated, performed with age-appropriate technique, and guided by the ALADA principle. The risk of a well-justified, correctly performed dental X-ray in a child is genuinely very small — measurably smaller than the risk of undetected interproximal decay progressing to abscess, or a developing dental anomaly going unnoticed until it creates a more complex problem.
What we owe children — as clinicians and as parents — is not avoidance of imaging, but careful, considered, minimal imaging. Every X-ray should earn its place.
At DMD Imaging, paediatric cases are approached with dedicated child-specific protocols on our digital systems, routine use of thyroid collars and lead aprons, and a referral pathway that ensures CBCT is only recommended when 2D imaging genuinely falls short. If you have questions about a specific paediatric case or imaging recommendation, our team is always available to discuss.
Frequently Asked Questions
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In most cases, no — not routinely. For a 4-year-old with no visible decay, no clinical concerns, and no history of dental trauma, an X-ray at a routine check-up is generally not indicated. X-rays in this age group are appropriate when there is a specific clinical question: suspected decay between teeth that can't be seen clinically, concern about a developing tooth, or trauma to a primary tooth affecting the root area. If your dentist recommends an X-ray for your 4-year-old, ask specifically what they're looking for. A clear answer is a good sign.
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A regular dental X-ray (bitewing, periapical, or OPG) produces a two-dimensional image and delivers a very low effective dose. CBCT produces a three-dimensional image and delivers a higher dose — though still much lower than a medical CT scan. For children, CBCT should only be used when the clinical question genuinely cannot be answered by 2D imaging, the smallest possible field of view must be selected, and dedicated paediatric dose-reduction settings should be used. A small-FOV paediatric CBCT with optimised protocols delivers approximately 0.05–0.15 mSv — equivalent to a few days of natural background radiation. Safe, but only when genuinely necessary.
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ALADA stands for As Low As Diagnostically Acceptable — a refinement of the more widely known ALARA (As Low As Reasonably Achievable). It means that radiation dose should be reduced to the minimum level at which the image still gives the clinician the diagnostic information they need. It's specifically applied in paediatric imaging because children's tissues are more radiosensitive than adults', and because they have a longer lifetime ahead in which any radiation-related effects could theoretically manifest. ALADA is not about avoiding X-rays — it's about ensuring every X-ray taken is genuinely necessary and performed at the minimum dose that still answers the clinical question.
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Yes. A lead apron and thyroid collar should be used for every dental X-ray in children. The lead apron protects the chest and abdomen from scattered radiation. The thyroid collar is particularly important for children because the thyroid gland is highly radiosensitive and sits in the neck — close to the area being imaged in dental X-rays. Some recent guidelines have debated whether lead aprons are necessary for modern, highly collimated digital equipment. However, in paediatric practice, routine use of both apron and thyroid collar remains the appropriate standard and should be expected at any reputable dental facility.
