Editorial 1/2018

Editorial 1/2018

20 years after the introduction of cone beam (CBCT) in dental and maxillofacial radiology by the seminal paper of Mozzo¹ and colleagues in 1998 it is about time to ask, how far did we get from there? By the way it is also noteworthy that two early abstracts^2,3 and the second seminal paper⁴ on CBCT have been published in Dentomaxillofacial Radiology.^1–4 So what’s the current state-of-the-art in dental and maxillofacial radiographic imaging in 2018, 20 years after CBCT has entered the stage? Well, surely CBCT has dominated the articles as single topic over the last 5 years. This holds also true for other journals reporting on radiological studies in other dental specialties. Coarsely summarized, the literature generally suggests that CBCT can be used for almost all radiological diagnostic tasks in dentistry. Here is an enthusiastic quote from a textbook published in 2011: “the next-generation CBCT or volumetric CT promises to produce in a single scan enough information to eliminate the need for conventional panoramic, occlusal, cephalometric, selected periapical and TMJ tomographic studies. The CBCT data will be superior to those gained from compiled series of two-dimensional (2D) images and the absorbed dose will be less”.⁵ This quote reflects a general attitude many clinicians seem to have towards the technique. But is this warranted from an objective perspective? It is obvious that three-dimensional (3D) radiographic information is superior to 2D for all those tasks, which inherently require a 3D assessment. A good example certainly is dental implantology, where the 3D-implant needs to be placed in a 3D bone support. Or facial trauma, where the surgeon needs to know in which direction and position bone fragments have been displaced in order to correctly reposition them. These are only two examples out of a multitude, where simple logical clues suggest that 3D-information adds value to the clinical work, and most probably also to the patient. Remembering that the ultimate goal in medical care is to improve or at least retain a patients’ health, patient-centred outcome is far up the efficacy ladder introduced by Fryback and Thornbury.⁶ So what do we know about CBCT from a patient-outcome perspective? Not so much, I am afraid. Most of the studies published on CBCT only reach level 1 (technical efficacy) and level 2 (diagnostic accuracy efficacy). Still only few studies reach level 4 (therapeutic efficacy) (e.g.^7,8) or even level 5 (patient-outcome efficacy) (e.g.^9,10). And, interestingly enough, the majority of these high-level studies are not so enthusiastic regarding the benefit with respect to patient outcome. So what do we know in 2018? It is out of question that we still need many more well-designed, thorough studies focusing on patient outcome, preferably (if ethically justifiable) randomized controlled trials. But when we objectively summarize the information currently available, we have to admit that CBCT is not the silver bullet and by far better than what we used all the decades before. Appropriately applied in a clinical setting, CBCT certainly is a very helpful diagnostic tool in dental and maxillofacial imaging. But as scientists we should consider facts not fiction, and thus we also have to admit that 2D radiographic imaging nevertheless has its many applications, not only because the radiation dose introduced by CBCT is considerably higher. Better knowledge requires better and more thorough, well-designed research. Dentomaxillofacial Radiology will further focus on such and actively convoy the future of CBCT as well as all other techniques relevant for dental and maxillofacial radiographic imaging.

Sincerely,

Ralf Schulze

Editor