Cone beam computed tomography: are you confident?
Jimmy Makdissi assesses how cone beam computed tomography has overcome barriers through the advantages it offers, and why extensive training is key to unlocking the technology’s full potential
Cone beam computed tomography (CBCT) imaging technology offers clinicians advantages over conventional dental imaging.
At a fundamental level, it provides a 3D view of dental structures otherwise visualised in 2D. It also facilitates the increased uptake of a digital workflow and surgically guided implant dentistry.
Technological advancements have resulted in radiation dose reduction and improved image quality, and the latest innovations offer a faster scanning time. As more manufacturers are entering the market, the cost of CBCT is decreasing, too.
Being able to use CBCT technology in treatment planning is a great benefit with the medicolegal pressures dentists face in the current climate. I also feel patient awareness about the use of CBCT in dentistry is increasing.
For practitioners delivering dental implant therapy, being able to obtain a 3D view of dental implant sites is hugely advantageous. CBCT technology allows the dentist to take accurate measurements of ridge height and width, and reliably assess bone quality.
The accurate identification of vital structures also decreases the risk of iatrogenic injuries, which leads to improved outcomes and patient satisfaction.
There are still barriers preventing clinicians from fully using CBCT imaging in their practices.
A limited understanding about the extensive capabilities of CBCT in dentistry is one example.
But this can be overcome by high quality training on all the applications, benefits, and limitations of the technology.
I want to pass on my knowledge and passion for CBCT, by offering courses that take dental and maxillofacial radiology to a new level. I present CBCT masterclasses and Association of Dental Implantology (ADI) study clubs on the topic for this reason; my aim is to increase awareness to as wide an audience as possible, from junior practitioners to clinicians in all positions of responsibility.
I have lobbied the manufacturers to offer CBCT training at the time of purchase, and, while the initial feedback has been positive, there is still work to be done in ensuring training is made compulsory and readily available to all CBCT users.
Main principles and common errors
The basic key principles that dentists should know is CBCT uses a combination of cone-shaped beams and a flat panel detector.
During acquisition, a simultaneous rotation of the beam and the detector occurs, and the captured data is reconstructed to form a cylindrical volume of the area of interest. This volume can then be viewed in multiple planes, including axial, coronal, sagittal, panoramic, and cross sections.
There are common mistakes and challenges with using CBCT, and I believe I can offer insight to help clinicians avoid them.
Errors that occur most frequently at the time of acquisition include inappropriate case selection, as well as inappropriate volume size and exposure factors, leading to unnecessary radiation exposure and suboptimal image quality.
Errors that occur most frequently after acquisition include difficulty manipulating images to display the required area, difficulty identifying vital structures, difficulty selecting slices for appropriate measurements, and missing pathological conditions. Training can remedy these issues and more; this modality is not to be used without proper instruction.
There are a number of guidelines that describe the potential clinical applications of CBCT. It is essential a thorough patient history and examination is conducted prior to any CBCT examination.
In many cases, conventional imaging is sufficient to make a diagnosis. However, when 3D information is required, or when there are contradictory clinical signs and symptoms, CBCT may be justified. Below is a summarised list for using CBCT:
- Impacted teeth localisation and potential resorption of adjacent teeth
- Third molar assessments, particularly in relation to the inferior dental canal position
- External or internal resorption
- Apical disease in the presence of negative conventional radiography findings
- Suspected root fractures
- Cysts and tumours of the jaw
- Maxillofacial trauma.
I cannot emphasise the importance of training enough. Training and more training. It will not only equip the dentist with the necessary theoretical and practical knowledge of CBCT, but it will also safeguard them against medicolegal implications.
Demonstrating the passion of ADI members for dental excellence, Dr Makdissi was one of the many speakers to present ADI study clubs so far this year. To discover other subjects available in the series or additional membership benefits from the ADI, visit www.adi.org.uk