One of the most spectacular examples of new technology in modern dentistry is the increasing use of cone beam computed tomography (CBCT). Dentolegal consultant Jim Lafferty looks at important aspects of the technique
The improvements in assessment, diagnosis and treatment planning from the use of CBCT are well known. In the fields of implant placement and third molar surgery we have seen significant uptake, and our endodontic specialist colleagues are now also seeing the benefits and how it can improve results for patients.
The use of such technology to improve patient care and reduce risk will be an attractive proposition to all involved, but there are potential pitfalls. Awareness of these is vital, particularly given the high costs associated with purchases of this type.
There is a considerably higher exposure to ionising radiation that increases the risk of developing a malignancy, so we should all be able to justify why any CBCT is being used, even if you are prescribing the imaging to be taken elsewhere. In some jurisdictions there is now a legal requirement to record this justification in writing. Members in those (countries/markets) report that this means they are more careful to consider both the benefits and the risks associated with CBCT. As a result, they have reduced the numbers of CBCT images they take, reducing the amount of exposure to ionising radiation.
If you are responsible for assessing the resulting image, you should ensure that you can demonstrate that you have suitable training for this and make a written record of the assessment. There are enormous amounts of information to be gleaned from these images and the person reviewing the slices has the responsibility to check for pathology in all those slices – even at sites distant to the area of interest.
In the accompanying case report, you will see that it is very important to establish who will be reporting on the image.
The key points dentists should consider in the area of CBCT are:
- Arrangements – who will be responsible for reporting?
- Assess – a CBCT without clinical examination is very difficult to defend.
- Balance – the risks of ionising radiation against the clinical information gained.
- Minimise – can the same information be obtained with a lower dose x-ray?
- Justification – record in writing the reason for taking the x-ray.
- Report – there should be a written report, leading to the normal recording of diagnosis, treatment options discussion, risk discussion, treatment planning and consent.
Mr D was referred to an oral surgeon for pain related to his temporomandibular joint issues. During the early assessments a CBCT was prescribed, carried out in a remote CBCT and imaging centre and a specialist radiologist report ordered. Over a year later, a further CBCT was ordered from the same centre when symptoms had spread.
The patient went on to develop a cancerous neuroma in his tongue, which by now had spread into the lymph nodes, and was considered inoperable.
The family complained to AHPRA, and the oral surgeon contacted Dental Protection. He was particularly concerned as his records of the patient’s treatment were somewhat brief and generally of a low standard. However, with assistance from Dental Protection, the member was able to show that he had ordered specialist reports and that the developing neuroma had been missed in the original scan. It was put forward that the responsibility for failing to diagnose the tumour was not the oral surgeon’s
Naturally the member was keen to emphasise in his response how distraught he was at hearing the news, but he did not consider the complaint showed any wrongdoing on his part. This was recognised and the case was dismissed.
- All radiographs should have a written report.
- By having the image reported on by an appropriate specialist, the responsibility for spotting pathology outside the area of interest is not the dentist’s.