Radiographs – risk management considerations

Radiographs (referred to hereafter as the colloquial albeit incorrect “x-rays”) are one of a dentist’s most important tools in the diagnostic process as well as being a useful aid in communication with patients. Because the taking of x-rays is common and usually straightforward, the value that radiology affords the practitioner can often be underestimated. In addition to their obvious clinical benefits, x-rays are often of key importance in defending complaints from disgruntled patients about treatment, and sometimes can be THE key in determining the entire course of a complaint or claim as you will see in some of the following case studies.

When it comes to the crunch, it is surprising how often to a member’s regret and/or embarrassment, the simple x-ray has been overlooked, or is poorly fixed or cared for, poorly taken in the first place, or been misplaced. Like other forms of patient records, in a legal setting, the quality of x-rays contributes to the impression of the quality of the treatment, especially when there may be little else available to base an assessment on. An excellent diagnostic x-ray is a delight to see!

Dentists have a legal duty to ensure that patients are treated with skill and care. This duty begins with the initial consultation process and involves:

  1. Duty to diagnose
  2. Duty to inform

There is then a duty to ensure treatment is carried out to an appropriate standard.

Where a practitioner fails in any of these duties, and the patient suffers in any way as a result, the patient has a potential claim. It will then be a matter of establishing whether the actions taken, or, perhaps not taken, were reasonable in the circumstances.

Let’s look at the first two duties in the context of x-rays. I would like to highlight that this is a greatly simplified view just for the purposes of illustration.

Your duty of care to your patients

Duty to diagnose

A practitioner has a duty to diagnose dental disease, occlusal disturbances and oral pathology so that, after appropriate discussion with the patient, treatment can be provided in a timely manner and the patient restored to oral health. “Failure to diagnose a condition correctly, in circumstances where a reasonably competent member of the same class of practitioner would not have so failed, will render a doctor [/dentist] liable in negligence”.[1]

Case 1

A patient presented seeking cosmetic enhancement of his smile. After appropriate discussion, bleaching and porcelain veneers were decided upon along with replacement of a pre-existing anterior crown. The treatment was completed in a series of appointments and the patient left apparently happy. Shortly afterwards a request for records and letter of complaint were received. The patient had sought treatment elsewhere and been advised that the re-crowned tooth now required extraction due to failure of the underlying root canal therapy that had been performed many years earlier by a previous dentist. The patient complained that the dentist had failed to take updated x-rays prior to commencement of the cosmetic work and requested assistance with the cost of implant replacement.

Comment: An updated x-ray had indeed not been taken of the tooth prior to the crown being replaced. In the absence of symptoms, it had been assumed that the root therapy was sound. Sometimes patient pressure to keep costs down can sway dentists against taking x-rays which would otherwise have been taken without hesitation. Resist this temptation. Always take the x-rays you need to ensure an unequivocal diagnosis, especially before commencing expensive or irreversible treatment. When you compare the cost of an x-ray and the information it affords

you to the overall cost of treatment, the additional expense is insignificant.

Case 2

A patient was referred away for removal of most of his teeth under general anaesthesia, and returned for issue of immediate dentures and post-operative management. Over the subsequent months, the patient was cared for by different dentists at the practice and had several small bony sequestra removed and numerous denture adjustments. However the patient continued to experience pain. He was a heavy smoker and had failed to comply with instructions to cease smoking during the post-operative healing phase, and this was considered a possible contributing factor to his ongoing problems. After numerous months of persisting discomfort, the patient sent the practice a letter expressing his desire to sue for pain and suffering, and sought treatment elsewhere. An x-ray of the upper anterior region taken by the dentist at the new practice revealed that a large portion of an incisor root had been left behind. Removal of this piece resulted in rapid settling of the patient’s remaining symptoms.

Comment: Whilst common things occur often, always keep the uncommon in mind! It was so unexpected that a straight rooted anterior tooth would have fractured that the taking of an x-ray to check for a retained root was overlooked. If no obvious cause for a patient’s problem is evident, it might be worth taking an xray to assist in diagnosis.

Case 3

A lady had attended a dentist regularly for six years having examinations and minor restorative work done. After moving house, she attended a different dental practice. A check-up was done and bitewings taken. The patient was shocked to hear that she required 5 major fillings done and one extraction – in the past she had been used to needing either nothing done or only one or two small fillings. She sent an angry letter to her former dentist requesting copies of her records and complaining that he had done inadequate examinations, failed to take sufficient x-rays, and had failed to diagnose urgent treatment.

Comment: Taking regular x-rays is a necessary part of the diagnosis and monitoring of the dental status. If the patient declines having x-rays taken, ensure this is noted in the patient’s records along with the reason. You may need to refer to this later, should a patient allege deficiencies in your treatment that the presence of x-rays would have assisted with.

If you are the subsequent treating dentist, bear in mind that small lesions or other problems that you detect may have been known to the previous practitioner. Sometimes doubtful areas or incipient lesions are not immediately restored and instead their progress is monitored radiographically to check for any development. It is important that the findings on such x-rays are discussed with the patient and that the need for regular monitoring and possible future restoration is made clear. Ensure that you record a brief note about your discussions in the patient’s records.

Case 4

A young girl presented upon orthodontic referral for removal of deciduous canines. The dental practitioner was not provided with, nor took, any x-rays prior to the extraction. A permanent lateral incisor was misidentified as a deciduous canine, and was removed and given to the patient. The practitioner only became aware of the error following a call from the orthodontist.

Comment: Extracting teeth for orthodontic reasons is the most common scenario resulting in the wrong tooth being removed, because of anatomical similarities and the usually pristine condition of the teeth requiring extraction. Always ensure you view an x-ray prior to treatment so that there can be no ambiguity about tooth identity.

Duty to inform

Practitioners have a duty to inform patients of the potential risks or complications of a procedure. In the past, the Bolam principle dictated that the standard of what to warn patients about was set by what a significant body of other peers within the profession considered was appropriate at the time. However the 1992 Australian High Court decision in Rogers v Whittaker led to a changed responsibility in the duty to disclose such that patients must now usually be warned of any risk inherent in the proposed procedure that is considered material. “A risk is material if in the circumstances of the particular case, a reasonable person in the patient’s position, if warned of the risk, would be likely to attach significance to it, or if the medical practitioner [/dentist] is, or should reasonably be, aware that the particular patient, if warned of the risk would be likely to attach significance to it”.[2] Hence the standard of care with regard to warnings is now determined by what the individual patient may desire as opposed to relying solely on medical judgment.

Case 1

A man presented with pain from tooth 47. RCT was suggested as the ideal option with extraction the only alternative. The dentist took an excellent periapical x-ray which indicated proximity of the mandibular canal to the 47 root apices, and noted in the records a caution to himself to avoid exceeding working length on instrumentation.

Having thought about it overnight, the patient returned the following day with the decision made to extract. The tooth was atraumatically removed.

Three days later, the patient returned for review and reported paraesthesia of his lower right lip. Unfortunately, despite the note in his records, this normally meticulous dentist had failed to warn the patient of this risk, being more concerned at the time with the patient’s complicated medical history and possible adverse postoperative complications arising from that. He had also been surprised and slightly distracted by the patient’s decision not to save the tooth, and the extraction appointment had been somewhat hastily arranged.

The dentist’s longstanding good relationship with the patient placed him in good stead to manage the patient’s anxiety and to oversee the gradual return to sensation in the lip over the following months.

Comment: Commonly it is the third molar region where x-rays are deficient, and which can result in insufficient information with which to adequately warn the patient of the likelihood of nerve damage. However paraesthesia has at times been reported following removal of lower first and second molars and also premolars. On rare occasion, sensation has remained permanently impaired. Hence it is necessary to ensure that xrays of all lower posterior teeth destined for extraction show sufficient information beyond the tooth apices to indicate any relationship with the inferior alveolar nerve canal. This will enable suitable warnings to be provided to the patient of the chance of nerve injury occurring, should the x-ray indicate such a risk. This will go a long way in preparing the patient should the worst case scenario eventuate, as well as being of obvious assistance in defending any potential allegations of negligence.

Case 2

A dentist placed a filling in a new patient’s tooth, 14, which had a large carious lesion. The filling was apparently close to the pulp but the tooth was asymptomatic and the patient was not warned about the possibility of RCT being required at some later stage. The patient developed symptoms two months later and sought emergency treatment from a dentist at another practice who commenced the RCT. The patient sent a written complaint to the original treating dentist stating that tooth 14 needed RCT due to him not having done the filling correctly, and threatening to take the complaint to the Health Care Complaints Commission or to the Dental Board. 

Comment: Be mindful that complaints from new patients are far more frequent than complaints from existing patients with whom a relationship of trust has been established. If you are going to keep good records for anyone, ensure you do so for new patients!

The first dentist had not taken a pre-operative x-ray because the caries was clinically obvious. It is nevertheless often prudent to take a pretreatment film to ensure a full and proper diagnosis (in this case to check for chronic periapical infection); for the purpose of having a record of the patient’s presenting state (for your own records and treatment planning purposes as well as for any future dentolegal defence requirement); and as a tool to assist in communication with the patient about their treatment.

Had the dentist taken such an x-ray, he would have had irrefutable evidence that the depth of the original caries was the reason for the RCT requirement as opposed to any fault of his restoration or “drilling too far”.

[1] Dix, Errington, Nicholson and Powe, Law for the Medical Profession in Australia, Butterworth-Heinemann 1996, p 291.
[2] ibid, p 104.

Case 3

A dentist carried out a lower molar RCT and placed a post, core and crown. Eight years later she received a solicitor’s letter claiming expenses for approximately $5,000 subsequent to a fractured instrument being discovered in the mesial root and the need to have the tooth retreated. The dentist had taken pre-, intra- and postoperative x-rays during the root therapy which had allowed her to detect the fractured file and inform the patient. However there was nothing noted in the clinical records to prove that any discussions with the patient had taken place – the dentist could only rely on the fact that it was her usual practice to inform of a fractured file and whether or not it had been able to be bypassed or removed etc. The patient claimed that he had not been so informed. Whilst the dentist’s management may have been appropriate, because of the lack of evidence of her side of the story, liability was a problem and the case needed to be settled.

Comment: This example highlights the importance of documenting radiographic findings in the records and any discussions with the patient. An offer of specialist assessment should be recorded along with the patient’s response, particularly if it is to decline referral. A court will likely believe a patient’s version of events over a dentist’s in the absence of supportive clinical records. 

Sometimes a dentist will deliberately avoid taking an x-ray when something adverse has occurred, fearing or knowing the evidence that it will show, in order to claim ignorance of an event. However the delay in being informed of a problem (which may come courtesy of a subsequent treating practitioner) may only serve to further upset a patient and in some instances, unnecessarily complicate management and reduce prognosis. It is better to promptly inform the patient of the adverse event, and you may wish to consult the ADA for advice before doing so.

Case 4

A new patient presented to a young dental practitioner for treatment of pain from the lower right which she believed was emanating from tooth 46. On examination the dentist found that tooth 46 and 47 were equally mobile with a poor prognosis, but tooth 47 was more tender to percussion than tooth 46. The dentist recommended extraction of 47. The specific tooth to be removed was only identified to the patient by percussion – she was advised that the sorest of the two teeth was the one that was going to be removed. The patient was not informed that this was a different tooth to the one that she believed was the problem. To save on costs, the patient had refused to have an x-ray taken and because 47 was so mobile, the dentist did not insist, knowing that the extraction would be straightforward. The tooth was indeed easily removed and the patient paid and left.

Shortly afterwards she returned stating that the tooth she had wanted taken out was still present and she wanted it removed. The dentist complied and extracted tooth 46 for no charge. A courtesy call was made to the patient later that day to check her progress. She was in some pain but feeling more comfortable.

The following day the patient’s partner phoned accusing the dentist of having removed the wrong tooth and requesting a meeting. A very lengthy meeting ensued between the partner and the dentist during which the partner demanded compensation for two extractions having been performed instead of one. He mentioned that the dentist had not followed correct procedures by failing to take an x-ray and said that he was holding him liable for loss of the abutment (47) for a future prosthesis that had been planned subsequent to the extraction of 46. The dentist was asked to think about it and contact the partner back with an offer. A harrowing fortnight followed for the dentist during which the partner continued to harass and harangue. The matter was resolved with a payment and execution of a Deed of Release.

Comment: This case raises issues of informed consent, patient privacy (the need to confine discussions about a patient’s treatment with the patient involved), admission of liability, and the practitioner’s right to decline providing treatment in situations where the patient is unwilling to comply with advice (in this case to have an x-ray taken prior to an extraction). The patient had also failed to provide an address and it is in contravention of the Dental Practice Act 2001 (NSW) to provide treatment in such circumstances. Whilst other evidence would likely have established that correct treatment had been provided, the lack of a pre-operative radiograph left the dentist in a vulnerable position and would have been a significant impediment in defending the case.

Case 5

A patient attended with a broken upper molar tooth with all coronal tooth structure having been lost. The dentist only recorded the patient’s name and not other essential details such as address or medical history. He failed to take any x-ray. The extraction was attempted but after a struggle the dentist failed to remove more than one root. As he was in a hurry, the dentist sent the patient off with no further advice or offer of referral. A fee of $100 had been charged and paid. “One extraction” plus the tooth number was all that was recorded in the patient records about the appointment.

The patient subsequently phoned the dentist and advised that he had attended a specialist oral surgeon and had been informed that in addition to the retained root, the sinus had been perforated.

Comment: This case was settled promptly.

Remember this! 

  1. Take the appropriate number of films which, in combination with your other findings, allows you to be confident of your diagnosis (or at least the adequacy of your attempts to reach a diagnosis). You may need to take additional films from other angles to capture adequate information. Complaints about a dentist having taken too many x-rays tend to be much less common, and tend to be about incidents of much less significance, than complaints about a dentist having taken none/too few/inadequate x-rays. If in doubt, take another x-ray.
  1. Best practice suggests that pre-operative films be taken before commencing expensive work such as crown and bridge, implant procedures, orthodontics and endodontics. In the case of endodontics, additional films should be taken both after and usually during the treatment, even if using an apex locator, so that the progress and outcome of treatment can be monitored and documented.
  1. Ensure your x-rays are of diagnostic value – this involves both the clinical taking of the films and their processing. It is no good having excellent radiography skills if the film processing is substandard or vice versa. Bear in mind that you may be required to provide copies of your records to one of your professional colleagues one day or to the Dental Board or to a patient’s solicitor.
  1. Ensure that your x-rays are dated, labeled and, if the non-digital type, are mounted correctly. This also applies to copies of x-rays which you are forwarding to other practitioners as part of the referral process, particularly referrals for removal of teeth. Oversights in these areas have resulted in the wrong tooth receiving the wrong treatment, including extraction.
  1. Be mindful that different practitioners, including within the same practice, might be in the habit of mounting x-rays with left and right reversed.
  1. Record in the dental records what x-rays were taken, the date they were taken, the purpose (if not obvious from your other notes), and what diagnosis was made, including if there was no abnormality detected (“NAD”). This way if the x-rays are lost, you will have your diagnosis recorded as further evidence of the films having been taken. Writing down your diagnosis also aids treatment planning.
  1. In addition to lowered radiation, digital x-rays have the advantage of creating an electronic audit trail where dates cannot be tampered with or inadvertently recorded incorrectly. They are also easier to store and can be stored indefinitely without deterioration. Secure back-up procedures are required to prevent loss of information through system failure. The use of digital x-rays does however involve an initial learning curve for the practitioner who is new to the system to become familiar with it and adapt his or her diagnostic skills. Auxiliary staff will also require appropriate training. Some practitioners believe that the non-digital system produces images of superior quality to those of digital systems.
  1. With digital x-rays, it may be prudent to keep a copy of the first image you take before any manipulation of contrast, brightness etc is done to enhance the image, in case something goes awry with the process.
  1. Always keep a record if the patient refuses to have an x-ray taken and the patient’s reasons – apart from being good clinical practice, this may become important in defending a claim. Without any such notation, you may leave yourself vulnerable to allegations of “I never said I wouldn’t have x-rays”.
  1. It is best to advise the patient up front that a certain procedure will involve the taking of multiple x-rays and why. That way the patient is forewarned and any objections about “unnecessary” x-rays can be addressed before they become an issue during treatment.
  1. Avoid using cost minimisation as a reason for not taking an x-ray that you feel is important. When the treatment is expensive, involved or irreversible, the cost of x-rays is minimal by comparison. If the patient declines having an x-ray for financial reasons, perhaps more information is needed to assist their understanding of the need. In such cases commencement of the treatment should be reconsidered (eg in the case of a tooth extraction).
  1. If copies of non-digital x-rays are required, this can be arranged through radiology centres, dental teaching centres, and the radiology department of major public hospitals.
  1. If you are the owner of radiology equipment, you are legally obliged to ensure that it is properly installed, housed and maintained so that it is safe for staff and patients.

By the Advisory Services Team at the ADA NSW

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