PAGD Keystone Explorer Spring 2021

Keystone Explorer | Spring 2021 7 dentistry issues Q While no X-ray exposure can be considered free of risk, most dental diagnostic examinations, from small intraoral X-rays to large CBCT volumes, in and of themselves carry very low risk of harm to patients. The decision to prescribe any radiographic examination for a patient depends on the probability of the information being useful for a particular diagnostic question that otherwise cannot be determined using a thorough workup including clinical examination, a patient’s history, and review of prior radiographic examinations. These decisions must also be tailored to the needs of the individual patient, including their sensitivity to X-rays, with the goal of maximizing diagnostic utility while keeping radiation doses as low as diagnostically adequate. Large, exhaustively detailed volumes can be (and have been) written about this discipline (selection criteria for dental radiographic examinations), but for sake of brevity, this article will summarize the pros and cons of various 2D and 3D examinations as well as the steps any dentist can take to maximize the information gathered during these exams. GENERAL ADVANTAGES OF 2D IMAGING » Low radiation dose » High-resolution images » Improved diagnostic value for caries detection » Fewer artifacts » Quick acquisition, post-processing, and viewing (digital) » Cost-effectiveness GENERAL ADVANTAGES OF 3D IMAGING » Increased diagnostic yield in all dimensions (the most profound benefit) » Lack of geometric distortion » Localization of structures or disease extent » Capacity to analyze asymmetries » Ability to render various views, orientations, slices, sections, etc. (manipulation of the volume to improve perspective and diagnostic confidence) » Implementation of software tools (nerve tracing, 3D volume renderings, etc.) to highlight various structures (airway, TMJ, etc.) » Better opportunity for occult disease detection GENERAL DISADVANTAGES OF 2D IMAGING » Reduced ability to discern details in the dimension through which the subject is imaged » Geometric distortions » Technique sensitivity » Infection control concerns (intraoral radiographs) » Higher occurrence of superimpositions (all types but more so in extraoral images) GENERAL DISADVANTAGES OF 3D IMAGING » Radiation burden » Spatial resolution (can be excellent but still inferior to intraoral radiography most of the time) » Wide range of artifacts that preclude detailed assessment of fine structures (motion, noise/ graininess, streaking, beam hardening, calibration etc.) » Longer post-processing time required » Greater burden of interpretation of all structures and liability potential » Cost and availability