Oral and Maxillofacial Radiology Diagnosis: The Role of Image Modality Selection, Interpretation Skills and Use of Cone Beam Computed Tomography Technology

Setareh Lavasani, DDS, MS

GUEST EDITOR

Setareh Lavasani, DDS, MS, is an associate professor and the chief oral and maxillofacial radiologist in the division of oral radiology and advanced imaging at the Western University College of Dental Medicine in Pomona, California. She is a diplomate of the American Board of Oral and Maxillofacial Radiology and a fellow of the Global Dental Implant Academy. Dr. Lavasani has authored multiple scientific manuscripts and book chapters on topics related to oral radiology diagnosis and radiation biology including the first digital/ interactive oral radiology textbook, Fundamentals of Oral Radiology. She maintains an active dental imaging practice serving

WesternU dental clinics and external referrals. Dr. Lavasani serves on the board of Tri-County Dental Society (TCDS) and is a delegate representing the TCDS at the 2022 CDA House of Delegates. Dr. Lavasani is a fellow of the Global Dental Implant Academy. Conflict of Interest Disclosure: None reported.

Radiographic examination is an integral part of diagnosis and treatment planning in dentistry. For the central part of the 20th century, dentists utilized a combination of 2D intraoral and extraoral imaging for diagnosis and treatment planning of dental and maxillofacial conditions. These radiographic technologies provide 2D representations of 3D anatomic structures. Apart from compressing the 3D anatomy of the area being radiographed into a 2D image, 2D imaging possesses unique inherent limitations (including magnification, distortion and superimposition), together leading to misrepresentation of structures. In the late 1990s, 3D imaging, cone beam computed tomography (CBCT), which utilizes an extraoral scanner, was introduced as a valuable additional tool in dental imaging. CBCT images are acquired by utilizing a cone-shaped beam of ionizing radiation with an area receptor that is fixed on the rotating arm and captures multiple projections of the structures being imaged. Captured data is processed through complex computer software algorithms, and the data is reconstructed in three dimensions and displayed on the computer monitor.

With broader availability and utilization of CBCT in dental practice and to provide guidance on clinical implications of CBCT imaging, the American Dental Association Council on Scientific Affairs published an advisory statement on the use of CBCT in dentistry. The statement notes, “As with other radiographic modalities, CBCT imaging should be used only after a review of the patient’s health and imaging history and the completion of a thorough clinical examination. The selection of CBCT for dental and maxillofacial imaging should be based on professional judgment in accordance with the best available scientific evidence, weighing potential patient benefits against the risks associated with the level of radiation dose.”

The clinician’s professional judgment in selecting the imaging modality types, including intraoral, panoramic, CBCT or a combination, could play an essential role in the timely diagnosis and management of pathological conditions in the jaws. Furthermore, the acquired images should have clinically acceptable image quality (resolution and contrast) and sufficient coverage of the area of interest.

Dentists who utilize CBCT technology should have appropriate training in evaluating normal maxillofacial structures in three dimensions and be competent in evaluating the CBCT scans for potential pathologic findings. The importance of the practitioner’s responsibilities was further highlighted in the executive opinion statement published in 2008 by the American Academy of Oral and Maxillofacial Academy in the journal Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics: “It is the responsibility of the practitioner obtaining the CBCT images to interpret the findings of the examination. Just as a pathology report accompanies a biopsy, an imaging report must accompany a CBCT scan. Dentists using CBCT should be held to the same standards as boardcertified oral and maxillofacial radiologists (OMFRs), just as dentists excising oral and maxillofacial lesions are held to the same standards as OMF surgeons.”

This issue of the Journal of California Dental Association aims to highlight the value of adequate imaging and the significance of appropriate radiographic interpretation knowledge in the timely diagnosis of dentoalveolar pathosis. The applications of CBCT as part of diagnosis and treatment planning in implant digital workflow and orthodontics is explored, and “novel” applications of CBCT in endodontics as an adjunct modality with dynamic navigation in the management of calcified canals is also discussed.

My colleagues and I present a case of medically related osteonecrosis of the jaws (MRONG) resembling a Le Fort I fracture in the maxilla of a patient taking antiresorptive drugs with a delayed diagnosis resulting from lack of adequate imaging (suboptimal image quality and not enough coverage area). The article also discusses the critical role of comprehensive and methodological history-taking in patients on oral antiresorptive medications who might be at higher risk for developing MRONJ.

Dentists who utilize CBCT technology should have appropriate training in evaluating normal maxillofacial structures in three dimensions.

Dr. Mark Mintline and colleagues illustrate that the practitioner who operates a CBCT unit or requests a CBCT study must examine the entire image dataset. This is predicated on a thorough knowledge of CT anatomy for the entire acquired image volume, anatomic variations and observation of abnormalities. It is imperative that all image data be systematically reviewed for disease.

In the last years, the developments of computer-aided-design/computer-assisted manufacturing (CAD/CAM) technologies have brought great improvements in dentistry, especially in the field of oral implant surgery. 6–8 In the article by Dr. Rafeeq Rahman and colleagues, key steps and considerations in implant dentistry digital workflow starting are laid out, with a CBCT imaging for implantsupported fixed single or short-span restorations using a static implant guide.

In orthodontics, CBCT imaging facilitates the visualization and evolution of complex three-dimensional structures of the maxillofacial region without the superimposition and magnification of structures associated with panoramic images. Dr. Yoon and colleagues discuss current 2D and 3D imaging modalities and their utilization in evaluating dentoalveolar abnormalities, tooth impactions and growth pattern monitoring. The article explains the role of CBCT as an adjunct in clinical diagnosis and management of airways and obstructive sleep apnea (OSA), temporomandibular joint (TMJ) abnormalities and virtual surgical planning.

The value of the CBCT in the preoperative, intraoperative and postoperative assessment of complex root canal systems is well documented. Rigolone et al. first described the value of CBCT in planning for endodontic surgery. Endodontic surgery is often complicated in the posterior teeth by their proximity to anatomical structures. The mandibular teeth can be close to the mandibular canal, while maxillary molars are often close to the maxillary sinus. CBCT imaging provides several advantages for preoperative treatment planning, especially in maxillary posterior teeth with apical pathology. Dr. Villa and colleagues present a novel approach to managing a calcified canal using the Navident dynamic navigation system and CBCT imaging to access the distobuccal (DB) canal of a partially obliterated maxillary second molar. This article introduces available technologies that, when paired with careful case selection and clinical training, could improve the predictability of surgical endodontic procedures.

As the guest editor of this issue of the Journal, I am pleased to share the advances in the field of oral and maxillofacial radiology and hope to have highlighted the value of judicious use of advanced imaging, the importance of interpretation skills and the role of synergistic collaboration between general dentists and specialist colleagues in improving diagnosis, treatment planning and patient outcomes. I hope readers find these topics as exciting as I do.

Finally, I would like to acknowledge the support and encouragement I received from leaders at the Western University College of Dental Medicine. After accepting the invitation to become the guest editor of this Journal issue and throughout my eight years at Western University, I have been consistently encouraged and generously mentored to grow and learn through new professional opportunities. With this in mind, and with gratitude, appreciation and affection, I dedicate this issue of the Journal of the California Dental Association to retiring Dean Steven Friedrichsen and his wife Sue.