Cone Beam Computed Tomography in Orthodontics

Indications, Insights, and Innovations

Sunil D. Kapila

• Publisher: Wiley-Blackwell
• Year: 2014
• ISBN:
  9781118646595
• Edition: 1
• Topic: Medicine
• Subtopic: Orthodontics

Since its introduction to dentistry, cone beam computed tomography (CBCT) has undergone a rapid evolution and considerable integration into orthodontics. However, despite the increasing popularity of CBCT and progress in applying it to clinical orthodontics, the profession has lacked a cohesive, comprehensive and objective reference that provides clinicians with the background needed to utilize this technology optimally for treating their patients. Cone Beam Computed Tomography in Orthodontics provides timely, impartial, and state-of-the-art information on the indications and protocols for CBCT imaging in orthodontics, clinical insights gained from these images, and innovations driven by these insights. As such, it is the most current and authoritative textbook on CBCT in orthodontics. Cone Beam Computed Tomography in Orthodontics is organized to progress sequentially through specific topics so as to build the knowledgebase logically in this important and rapidly evolving field. Part I provides the foundational information on CBCT technology, including radiation exposure and risks, and future evolutions in computed tomography. Part II presents the Principles and Protocols for CBCT Imaging in Orthodontics, focusing on developing evidence-based criteria for CBCT imaging, the medico-legal implications of CBCT to the professional and the protocols and integration of this technology in orthodontic practice. Part III provides critical information on CBCT-based Diagnosis and Treatment Planning that includes how to interpret CBCT scans, identify incidental pathologies and the possible other uses of this technology. Part IV covers practical aspects of CBCT's Clinical Applications and Treatment Outcomes that encompasses a range of topics, including root morphology and position, treatment of impacted teeth, virtual surgical treatment planning and outcomes, and more.

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Contemporary Concepts of Cone Beam Computed Tomography in Orthodontics

Sunil D. Kapila, BDS, MS, PhD

Introduction

Truly transformative innovations are rare in most fields, but their emergence can generate a buzz that reverberates across disciplines. This is true especially in medicine and dentistry, which would stagnate without groundbreaking technologies that improve diagnosis, treatment planning, and prevention of disease. Among the advances in healthcare, radiological innovations are uniquely important as they have propelled advances in virtually most medical and dental specialties directly or indirectly. In this book, we examine how this technological cross-pollination works by detailing the broad impact of three-dimensional (3D) radiographic imaging on orthodontic diagnosis and treatment planning.

Several different technologies, including structured light, laser surface imaging, magnetic resonance imaging (MRI), computed tomography (CT), and cone beam computed tomography (CBCT), are currently available for 3D imaging. While these technologies differ in their operational details, all of them generate 3D images using the same general principles. In each of these imaging modalities, an emitted energy beam passing through or reflected from the body is modified by the structures that it encounters. A specialized sensor captures the modified energy beam, which then is converted into a 3D image by sophisticated software. Surface models, such as dental casts or slices through the 3D volume, which clearly display internal structures, can then be generated to improve diagnosis and treatment planning. Factors such as the desired image resolution, radiation exposure, soft tissue versus hard tissue visualization, and region of interest are used to determine which imaging modality is suited best for any given patient. Because of the need for orthodontists to image the craniofacial skeleton optimally and derive volumetric information, X-ray–based imaging is the best choice among these imaging technologies. Within the volumetric 3D imaging subset, CBCT, as opposed to the more expensive CT or MRI or higher radiation CT technologies, currently is the most preferred approach for such imaging.

Since the introduction of CBCT to dentistry, which first was discussed comprehensively at the 2002 symposium “Craniofacial Imaging in the 21st Century” and documented in the proceedings of the meet­­ing (Kapila & Farman, 2003), this technology has undergone a rapid evolution and considerable integration into orthodontics (Kapila et al., 2011). Typically the pattern of integration of a new technology into a discipline, such as CBCT's utilization in dentistry, starts with early enthusiastic adopters who hope to extend the technology's boundaries beyond its capabilities or utility, while others wait for evidence to justify the use of such technology and still others remain skeptical that the new technology will have any impact on their modality of practice, patient care, or treatment outcomes. Given the exponentially increasing research and clinical information on CBCT, it is likely that the latter group is dwindling as more clinicians begin to recognize the usefulness of CBCT, at least for patients presenting with specific clinical challenges. On the other end of the spectrum, the routine use of CBCT on every orthodontic patient remains a controversial issue since it is not clear that the information derived from CBCT enhances diagnosis or helps in modifying treatments in several case types, which is important particularly when weighed against the risks of radiation exposure.

This varied utilization of CBCT among clinicians exists within the context of research evidence, published case reports, or anecdotal observations on topics ranging from impacted teeth to temporomandibular joint (TMJ) morphology, many of which suggest that important information indeed can be obtained through CBCT imaging. Nevertheless, scientific evidence that the utilization of CBCT alters diagnosis and improves treatment plans or outcomes has only recently begun to emerge for some of its suggested applications. Also, for several of these recommendations in which the use of CBCT is logical and/or supported by scientific evidence, the specific indications for acquisition of CBCT images and protocols for imaging and extracting appropriate information have not been resolved fully. Finally, the information obtained from CBCT imaging requires a substantial level of expertise for interpretation that orthodontists currently may not have achieved (Ahmed et al., 2012), which has attendant medico-legal implications. Thus, despite the rapidly increasing popularity of CBCT and progress in understanding and applying it to clinical orthodontics, and possibly because of the large quantities of often disparate information on this imaging technology, a cohesive, comprehensive, and objective approach to its uses and advantages in orthodontic applications currently is lacking.

This textbook provides detailed, impartial, and state-of-the-art insights, indications, protocols, procedures, innovations, and medico-legal implications of CBCT. The insights gained from CBCT are contributing to novel or refined approaches to diagnosis, treatment, and biomechanic planning (Chapters 9–23), assessment of treatment outcomes (Chapters 12–15, 17, 19–23), and providing opportunities for novel areas of research (Chapters 4, 5, 12–23). These insights have been facilitated largely by the relative advantages of CBCT imaging over radiographic two-dimensional (2D) imaging.

This chapter provides an essential overview of the topics presented in this book with the goal of highlighting the current knowledge on CBCT technology, its applications in defining 3D craniofacial anatomy and treatment outcomes, incidental findings and their medico-legal implications, and evidence-based indications and protocols for clinical applications of CBCT. In reading this chapter and book, it will become apparent that while some applications and areas have advanced sufficiently with demonstrated scientific evidence for the efficacy of CBCT in enhancing diagnosis and treatment planning, the use of CBCT in other clinical situations still is evolving. Thus, depending on where this field is in specific types of cases, the topics may range from current science to implied clinical applications to actual utility in patients who present with specific clinical findings. It is likely that as the field advances and more evidence of the efficacy of CBCT emerges, its applications in orthodontics will increase or be modified. This will enable clinicians to realize the ultimate goal of increased treatment effic...