Judy Nguyen, Medical Radiographer

Role: Diagnostic radiographer — dental and maxillofacial imaging

Qualifications: Bachelor of Medical Radiation Science, Charles Sturt University; Graduate Diploma in Economics, University of New England; currently undertaking a Master of Data Science, La Trobe University

Registration: Registered medical radiation practitioner, diagnostic radiographer division, general registration, MRP0001785335

Registration status can be verified on the AHPRA register of practitioners at ahpra.gov.au. The imaging equipment she works with is described on the technology page, and the full team list is on the our team page.

A different National Board

Note the prefix. MRP is not a dental registration. Judy Nguyen is registered with the Medical Radiation Practice Board of Australia, not the Dental Board — both are National Boards under AHPRA, but they register different professions with different qualifications, standards and scopes.

This matters when reading any dental practice's team page. A DEN number means the Dental Board; ADP means dental prosthetist; MED means the Medical Board; MRP means the Medical Radiation Practice Board; OST means the Osteopathy Board. A practitioner working in a dental clinic is not necessarily a dental practitioner, and the prefix is the reliable indicator. The practice's own summary of dental registrations is on the dentists and registered specialists page.

The titles the law protects here

Ahpra's Guidelines for advertising a regulated health service set out the protected titles profession by profession. For medical radiation practice the protected titles are "medical radiation practitioner, diagnostic radiographer, medical imaging technologist, radiographer, nuclear medicine scientist, nuclear medicine technologist, radiation therapist" — a longer list than most, and "radiographer" is on it, which is why the word is not used loosely. The same guidelines list the profession's divisions as "Diagnostic radiographer, nuclear medicine technologist, radiation therapist".

For comparison, the dental profession's protected titles are "dentist, dental therapist, dental hygienist, dental prosthetist, oral health therapist" — a separate list, under a separate Board. Neither list contains the other. A person "must not knowingly or recklessly claim or hold themself out to be registered or qualified to practise in a health profession or a division of a health profession if the person is not so registered" (National Law section 117, as Ahpra summarises it), and that cuts both ways across the two Boards.

Background

Judy Nguyen qualified with a Bachelor of Medical Radiation Science from Charles Sturt University. She also holds a Graduate Diploma in Economics from the University of New England and is completing a Master of Data Science at La Trobe University.

She was drawn to radiography through an interest in imaging, combining technical precision with a visual eye. Outside work she travels, draws and does arts and crafts.

What a medical radiographer is

A diagnostic radiographer is a registered health practitioner who produces diagnostic images. The Medical Radiation Practice Board of Australia registers three divisions: diagnostic radiographers, radiation therapists (who deliver radiotherapy), and nuclear medicine technologists.

The qualification is a three- or four-year university degree in medical radiation science, followed by a supervised practice programme before general registration. Registration is renewed annually and is subject to standards for recency of practice, continuing professional development, professional indemnity insurance, criminal history and English language skills.

A radiographer is not a radiologist. A radiologist is a medical practitioner — a doctor — who has completed specialist training in interpreting images and reporting on them. A radiographer produces the image; a radiologist (or, for dental imaging, an appropriately trained dental practitioner or an oral and maxillofacial radiologist) interprets it. Both roles matter and they are not interchangeable. Why would I need to see a dental specialist? explains the same principle across the dental specialties.

Dento-maxillofacial radiology is itself one of the 13 recognised dental specialties — the Dental Board of Australia lists 13 specialties "approved by the Australian Health Workforce Ministerial Council", and dento-maxillofacial radiology is the first of them. It is one of only two specialties recognised by the Dental Board but not by the Dental Council of New Zealand, the other being forensic odontology; the two bodies "have 11 specialties in common". A dentist who holds that specialist registration is a different person again from the radiographer who takes the image.

What a radiographer does in a dental setting

• Intraoral radiographs — bitewings, periapicals, occlusal views. These are what find decay between teeth before it is visible: the stages of dental decay and can you reverse tooth decay and do I need a filling?
• Orthopantomograms (OPG) — the panoramic view of both jaws, used for wisdom teeth among much else
• Lateral cephalograms — the side-on skull view used in orthodontic assessment
• Cone beam computed tomography (CBCT) — three-dimensional imaging of the jaws, used for implant planning, bone grafting assessment and jaw surgery
• Positioning and technique, which is the difference between a diagnostic image and a repeat exposure
• Dose optimisation — selecting the smallest field and lowest exposure that will answer the clinical question
• Quality assurance on the equipment

Radiation: the honest numbers and principles

Dental imaging uses ionising radiation. The doses are small, but "small" is not "zero", and the governing principles are worth understanding. How safe are dental x-rays and how safe are dental X-rays and when do they become unsafe? are the patient-facing versions of what follows.

Justification. Every exposure must be clinically justified — there must be a specific question it will answer, and the answer must be capable of changing what happens next. "Routine" X-rays taken to a fixed calendar schedule regardless of the patient's risk are not justified. A low-risk adult with no decay history needs bitewings far less often than a high-risk patient — the same risk-based logic as how often should I go to the dentist?

Optimisation — ALARA. As low as reasonably achievable. Digital sensors need substantially less exposure than the film they replaced. Rectangular collimation confines the beam to the sensor rather than a wider circle. Correct positioning avoids retakes, and a retake doubles the dose.

Relative doses. A single intraoral radiograph delivers a very small dose — comparable to a fraction of a day's natural background radiation. An OPG is somewhat higher. A cone beam CT is substantially higher than either — the exact figure varies widely with the field of view and the machine settings, and a large-volume scan can approach or exceed the dose of a conventional medical CT of the same region in some configurations. That is why CBCT is justified for implant planning, assessing a root against the inferior alveolar nerve, complex endodontic and surgical assessment, and impacted teeth — and is not justified as a routine screening tool. What do I need to know about dental implants? and why is the microscope so crucial in endodontic treatment by a specialist? show what those images are for.

The published figures, and how to read them

Because "small" is not a number, here are the numbers. The International Atomic Energy Agency publishes typical effective doses for dental procedures:

The IAEA's own summary of what that means: "the doses from intraoral and cephalometric dental radiological procedures are lower, usually less than one day of natural background radiation. Doses for panoramic procedures are more variable, but even at the high end of the range are equivalent to a few days of natural background radiation which is similar to that of a chest radiograph. CBCT doses cover a wide range, but may be tens or even hundreds of µSv of effective dose higher than conventional radiographic techniques, depending upon the technique." It adds that "rapid technological improvements to CBCT equipment mean that typical dose ranges are likely to change" — so a figure quoted anywhere, including here, is a snapshot.

And one caveat that almost never survives into patient information, so it is stated here. Effective dose is a comparison tool, not a personal risk estimate. The IAEA is explicit: "effective dose and its associated risk should not be applied to individuals, but can be used to compare between modalities, techniques and other sources of exposure". Anyone converting a microsievert figure into your personal odds of anything is overreaching the quantity.

The measurable quantities used for day-to-day quality assurance are different again — entrance surface kerma for intraoral work, kerma-area product for panoramic, cephalometric and CBCT. The IAEA gives adult reference ranges of "0.65 to 3.7 mGy in terms of entrance surface kerma" for intraoral radiography and "3.3 to 4.2 mGy in terms of entrance surface dose" for panoramic, and notes that "a qualified expert (e.g. medical physicist) can measure the abovementioned dose quantities".

A gap in the Australian benchmarks

In most of medical imaging, a service compares its own doses against a national diagnostic reference level — which ARPANSA defines as "an indicative measure used to assess whether, in routine conditions, the amount of radiation used is unusually high (or low) for a specified procedure", stressing that "a DRL is not a regulatory limit, it is a benchmark that when exceeded triggers a review".

For dentistry, that benchmark does not exist. ARPANSA states that "there are no Australian DRLs for planar radiography, dental X-ray, cone beam CT or mammography"; its published DRLs so far cover CT, nuclear medicine and PET, and coronary angiography. That is a gap in the national infrastructure, not a loophole a practice is exploiting — but it does mean the practical safeguards in dental imaging are equipment compliance testing, the operator's technique, and the clinician justifying each exposure, rather than an audit against an Australian number.

Children are more radiosensitive than adults, and exposure settings should be adjusted for them rather than using adult defaults. The IAEA's reference ranges for lateral cephalometric radiography make the difference visible: "41 to 146 mGy.cm2 (adults) and 25 to 121 mGy.cm2 (children)". When should I take my child to see an orthodontist? covers the imaging that usually accompanies an early assessment.

Pregnancy is not an absolute contraindication to dental radiography — the beam does not include the abdomen and the dose to the fetus is effectively negligible — but the justification test still applies, and elective imaging is commonly deferred. Tell the practitioner if you are or may be pregnant. See is it safe to visit the dentist during pregnancy? and pregnancy and dental health.

What you are entitled to ask: why this image is being taken, what it will show, what would change as a result, and whether an existing recent image from another practice could be used instead. Radiographs belong to the record and can be transferred; repeating imaging that already exists is avoidable dose. If you are taking a plan elsewhere, a second opinion is a normal reason to request them.

Regulation of dental radiography in Victoria

Radiation apparatus must be registered, premises must meet shielding requirements, and use is governed by the Radiation Act and its regulations, with national guidance from ARPANSA. Equipment is subject to periodic compliance testing, and operators must be appropriately qualified.

A dentist may take radiographs themselves — it is within the dental scope of practice. Having a registered radiographer take them is not a legal requirement; it is a staffing choice that tends to produce more consistent positioning, particularly for panoramic and three-dimensional imaging where technique errors are common and costly in retakes.

Whoever takes the image, the Dental Board's Scope of practice registration standard (in effect 1 July 2020) requires "dental practitioners to practise within the scope of their education, training, and competence at all times", and the equivalent principle applies under the Medical Radiation Practice Board.

Registration

The Medical Radiation Practice Board of Australia registers diagnostic radiographers, radiation therapists and nuclear medicine technologists. Registration carries an MRP prefix, is renewed annually, and conditions or undertakings appear on the public register at ahpra.gov.au.

The Dental Board of Australia — a separate National Board — registers dentists, dental specialists, dental hygienists, dental therapists, oral health therapists and dental prosthetists. The Dental Board notes that "Ahpra publishes an online register of all dental practitioners that provides the profession and the public with up-to-date information about a dental practitioner's registration status", and that it "also includes details of the specialty or specialties for dentists who hold specialist registration". One search covers every National Board, so you can check the radiographer, the dentist and the specialist in the same place — finding a dentist online in Australia.

Common questions

I am having a wisdom tooth assessed and a CBCT has been suggested. Is the extra dose worth it?

Sometimes, and less often than it is offered. This is one of the few dental imaging questions with a direct randomised-trial answer, and it is worth reading before you agree.

A 2022 systematic review in BMC Oral Health, drawing on seven randomised controlled trials, concluded that “CBCT should not be used routinely to assess MTMs, and it is unlikely to reduce risk of nerve injury even in most high-risk cases” — MTMs being lower wisdom teeth. It found “moderate quality evidence that CBCT does not routinely translate to reduced incidence of nerve injury in MTM removal”, and low-quality evidence from three studies that CBCT “does not influence the duration of third molar surgery”.

The trade-off it quantifies. A small-field CBCT of a wisdom tooth carries “approximately a five-fold increase in radiation compared to an OPG”, and the preoperative costs are “approximately four times greater”. Both figures are relative rather than absolute — the review gives no microsievert number, and the IAEA table above is the place to look for that.

Where it is still justified. The same authors say CBCT “should be reserved for high-risk cases where the prescriber feels 3D imaging has potential to change the treatment decision, or surgical technique, in a manner that may avoid nerve injury”, and that the decision “should therefore be carefully justified incorporating individual patients' expectations and values”.

What makes a case high-risk is visible on the ordinary panoramic image: three signs in particular — darkening of the root, diversion of the nerve canal, and loss of canal cortication. Where those signs are present, older work has quoted nerve injury incidence as high as 20%, with 4% permanent; those are secondary figures attributed to Renton (2009) and they apply only to teeth showing those signs, not to wisdom-tooth surgery in general. For context, the trials in the review itself recorded 10 permanent injuries (1.1%) across 888 higher-risk removals — lower than expected — and none of the trials found a significant difference in permanent nerve injury between the CBCT and OPG groups.

So the question to ask is narrow and answerable: what on my OPG makes this high-risk, and what would the 3D scan change about how you operate? A clear answer justifies the scan. "To be thorough" does not. See wisdom teeth.

Can you tell me what the X-ray shows?

Not the person who takes it, and that is a scope rule rather than reticence.

As set out above, a radiographer produces the image; interpretation and reporting belong to a radiologist, or for dental imaging to an appropriately trained dental practitioner or a dentist holding specialist registration in dento-maxillofacial radiology. The professional obligation that draws that line is the same in both Boards — the Dental Board's scope of practice standard requires practitioners to work within their “education, training, and competence at all times”, and the Medical Radiation Practice Board applies the equivalent principle.

Why it matters rather than being bureaucratic. A half-answer given in the imaging room, out of context and without your clinical history, is the version you will remember and worry about. Radiographic findings are read alongside symptoms, examination and history — the same shadow means different things in different mouths.

What you can ask the radiographer, and should: what the image covers, how long it takes, what the positioning involves, why this view rather than another, and what will happen if it needs repeating. Those are squarely within the role.

What to ask the practitioner who requested it: what they were looking for, what they found, whether it changed the plan, and — if something incidental turned up — what follow-up it needs. Ask to see the image on the screen while they explain it. Most people find a radiograph far less alarming once someone has pointed at what they are actually describing.

How often should I have X-rays? Is there a schedule?

There should not be one, and that is the point.

The justification principle stated above rules out a calendar. The published radiology position is that “strict and individualized justification should determine the prescription of each radiograph”, and that a justified radiograph “should make a substantial contribution to distinguishing between treatment options”. In paediatric practice the shift has been explicit — one study of intraoral radiographs in children records that “X-ray screenings are no longer recommended”, replaced by the European Association of Paediatric Dentistry's approach of “an individualized and patient-specific justification for X-ray diagnostics as best clinical practice”.

What actually sets the interval is your risk of the thing the image is looking for: decay history, current decay activity, diet, dry mouth, gum condition, the number and age of existing restorations, and how easily the contact points between your teeth can be examined by other means. Someone with no new decay in a decade and good interdental cleaning is in a different position from someone with three new lesions last year.

And there is no Australian number to appeal to. As noted above, ARPANSA has not published diagnostic reference levels for dental X-ray, and we could not find an Australian recall-interval standard for dental radiography in the independent reference material behind these pages. That absence is a reason to ask for the reasoning, not a reason to assume any particular interval is wrong.

So ask two things at the appointment where imaging is proposed: what has changed since the last set, and what this set would change. A practitioner who can answer both is justifying the exposure in exactly the way the principle requires.

Can I get copies of my images, and can another practice use them?

Yes to both, and it is worth doing rather than repeating the exposure.

Radiographs are part of your health record. Ask for them in writing, name what you want — intraoral images, OPG, CBCT data, and the date range — and say whether you want them sent directly to another practitioner or given to you. Digital transfer is normal, faster and better quality than a print, and a practice can usually send them to a named clinician on request.

Ask about the CBCT specifically, because it is not a picture. A CBCT is a dataset, and what another clinician can do with it depends on what is supplied — a set of exported images is not the same as the raw volume that can be re-sliced and re-measured. If the scan is going to an oral surgeon or an implant planner, ask for the data in the form they need rather than assuming a PDF will do.

Why it matters here more than elsewhere. Repeating an image that already exists is avoidable dose, and it is the single commonest avoidable exposure in dentistry. The principle that a justified radiograph must “make a substantial contribution to distinguishing between treatment options” applies just as much to the second copy of an image as to the first.

Two reasonable expectations. A fee may be charged for providing copies, so ask what it is beforehand. And ask how long it will take, in writing, so there is a date to follow up against — particularly if an appointment elsewhere is already booked. If you are weighing a plan, second opinions and corrective dentistry sets out how that works here.

One thing worth knowing: a newer image, or a different view, is often genuinely justified even when an old one exists — things change, and an OPG does not answer a question that needs a periapical. "You already have one" is a reason to ask which applies, not an argument to refuse.

Related reading

• Oral cancer: how your dentist can help with early detection
• What is orthognathic surgery?
• EMG muscle mapping and bite force analysis: how we diagnose jaw problems
• Price guide — indicative fees, and what changes them

Practical details

Judy Nguyen's registration can be checked free on the AHPRA public register at ahpra.gov.au. For questions about imaging, ask the practitioner who requested it. Call 13 13 96, or use the contact page.

Smile Solutions, Level 1, 220 Collins Street, Manchester Unity Building, Melbourne VIC 3000. Phone 13 13 96, or theteam@smilesolutions.com.au. Monday–Friday 8.00am–6.00pm, Saturday 8.30am–1.30pm, Sunday by appointment.

Sources for the externally verifiable statements on this page

• Ahpra — Guidelines for advertising a regulated health service, for the protected titles and divisions of both professions and the holding-out provisions.
• Dental Board of Australia — Specialist Registration and the Scope of practice registration standard.
• International Atomic Energy Agency — typical effective doses, entrance surface kerma and kerma-area product ranges for dental imaging, and the caveat on applying effective dose to individuals.
• ARPANSA — the definition of a diagnostic reference level, and the modalities for which Australian DRLs do and do not exist.
• BMC Oral Health (2022) — systematic review of CBCT versus panoramic radiography before lower third molar surgery.
• Peer-reviewed study of intraoral radiograph dose and justification in children and adolescents (PubMed Central).

This page records qualifications as published by the practice. General information only — it is not a diagnosis or a treatment plan. Whether any particular image is appropriate is a clinical judgement for the practitioner requesting it. Published dose figures are quoted as at the date of the source and are expected to change as equipment changes; confirm current figures with the publisher.

Smile Solutions trades under ABN 28 193 514 103.