Pacific Coast Society of Orthodontists Bulletin Summer 2012 - (Page 36)

SUMMARIES NORTHERN REGION THREE-DIMENSIONAL VOLUMETRIC IMAGING: AN EMERGING DIAGNOSTIC TOOL Presented by James Mah, DDS, MSc, MRCD, DMSc, at the PCSO Northern Regional Meeting, February 24, 2012. Summarized by Charity Siu, DMD, PCSO Bulletin Northern Region Editor. r. James Mah has devoted a significant portion of his career to 3-D imaging, and he is devoted to ensuring that orthodontists can benefit from his work. As compared to other emerging technologies in dentistry, cone beam comDr. Mah puted tomography (CBCT) has evolved the most by far. Since 2005, adoption of the technology has doubled every year. In North America alone, 8000 units have been installed, and over 1000 items related to CBCT have appeared in peer-reviewed journals. In 2010, the AAO recognized that there may be situations in which CBCT is of value, but not necessary, for diagnostic purposes. Users of the technology state that CBCT changes the diagnosis and treatment plans for seemingly routine cases. In fact, CBCT has shown us that patient anatomy is diverse, and that conventional imaging accuracy is limited; it has also shed light on the limitations of tooth movement, growth and development, and treatment effects such as palatal expansion and functional appliances. CBCT poses benefits for all disciplines of dentistry. Oromaxillofacial surgeons can visualize the mandibular third molar proximity to the nerve canal. Oral medicine clinicians can view condylar surface erosions. Endodontists are able to find more accessory canals and diagnose fractures. Orthodontists can assess canine D impactions and root position. Most preadjusted appliances were formulated based on 2-D imaging—perhaps in time we will see the emergence of new prescription appliances. As a practicing orthodontist, it was alarming to see Dr. Mah’s case examples of dolicocephalic, openbite patients. Many had thinned and stretched out alveolar processes that showed very little surrounding bone, resulting in root resorption of the incisors. At the same time, it was very valuable to see the use of the midpalatal suture and the pattern of the bone to determine the degree of interdigitation. Perhaps the most effective diagnostic change for orthodontists is the knowledge that the sinuses and airway affect the development of the bony architecture, which then translates into malocclusions such as openbites and impacted canines. Currently, Dr. Mah is running a study to determine patients’ attitudes towards CBCT. It appears that females approve of the benefits of CBCT, while males approve of the cost. Another study compared examiners’ experiences with CBCT along with changes in diagnosis; the most common changes in diagnosis involved airway evaluation, the need to refer to an ENT, TMJ status, and the morphology and position of tooth roots. It was apparent that more detail-oriented orthodontists were more likely to benefit from CBCT. CBCT may not consistently change an orthodontist’s plan for treatment; however, it gives the orthodontist a more complete picture that will enhance biomechanic strategies and treatment planning. However in the end, it is up to the individual orthodontist to choose how he or she practices. S 36 PCSO Bulletin • SuMMeR 2012

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Summer 2012

President's Message
Executive Director's Letter
PCSO Business
AAOF Report
PCSO at a Glance
Practice Management Diary
Faculty Files
Correction to Faculty Files article, Spring 2012
Seasoned Practicioner's Corner
Case Report Pre-Treatment
Portrait of a Professional
From Good to Great in a Tough Economy
Three-Dimensional Volumetric Imaging: An Emerging Diagnostic Tool
Destination Success
Case Report Post-Treatment
Earl's Pearls

Pacific Coast Society of Orthodontists Bulletin Summer 2012