Pacific Coast Society of Orthodontists Bulletin Summer 2015 - (Page 14)

Special Section Editorial CBCT Cone-Beam Computed Tomography Special Section on CBCT Dr. Jae Hyun Park PCSO Bulletin Editor-in-Chief Once again, it is time for our PCSO Bulletin special issue focusing on a current topic in orthodontics. In this second annual feature, we focus on conebeam computed tomography (CBCT) technology. On July 1, 1994, two NewTom engineers, Giordano Ronca and Daniele Godi, performed the first complete CBCT scan on an anthropomorphic skull. CBCT imaging has improved significantly in just 20 years, and has increased in popularity for use in orthodontic diagnosis and treatment planning. In our 2010 survey of postgraduate orthodontic program directors, CBCT imaging was accessible in 83% of post-graduate residency training programs, and was used on a regular basis in 73%.1 Orthodontic graduates are entering the field with increased exposure to this diagnostic tool, both didactically and clinically. In a 2007 survey of orthodontic residents, 28% reported definite plans to incorporate CBCT into their future private practices.2 cation. It is also valuable in the evaluation of craniofacial deformities and abnormalities. Three-dimensional (3D) depictions of a cleft palate case can allow the surgeon to shape and place a bone graft in the most ideal location for dental and soft tissue support. CBCT is also useful in locating and orienting displaced fragments prior to fixation in cases of fracture and trauma.4 All of these surgical procedures have benefited from increased accuracy and predictability with the advent of 3D imaging technologies. CBCT Finding its Niche CBCT, while not yet common, has found its niche in elucidating problems that are beyond the scope of conventional two-dimensional (2D) imagery. The accuracy, reliability, and repeatability of CBCT technology have been reported in numerous studies. This diagnostic tool is best utilized to confirm a diagnosis in three dimensions, from the location of an impacted tooth to the extent of a craniofacial deformity. The most common use of CBCT in orthodontics is to allow for visualization of supernumerary and impacted teeth, especially canine impactions.3 Identifying the precise position and angulation of an impacted tooth will aid in treatment planning and in determining the force vector needed, avoiding potential collisions with adjacent teeth and preventing exacerbation of root resorption. If the impacted tooth is close to important anatomic structures such as the inferior alveolar nerve or maxillary sinus, CBCT is a useful armamentarium in deciding whether to use orthodontic traction, extraction, or autotransplantation.4 The assessment of temporomandibular joint disorders has benefited significantly from CBCT imaging. The before and after treatment position, size and shape of the condyles, glenoid fossae, and articular eminences offer clues to potential dysfunction, disharmony, and occlusal interferences. CBCT can be used as a post-treatment assessment tool to successfully evaluate the condylar response to functional orthopedic treatments; it is also useful for the assessment of maxillofacial growth and development. Another increasingly popular use of CBCT is in airway assessment. The ability to perform precise 3D measurements is an advantage of computed tomography (CT) technology over traditional 2D imaging. CBCT enables a more scientific study of obstructive sleep apnea and the influence of craniofacial skeletal pattern on airway dimension. Radiation dosage continues to be a major factor in both practitioner and patient acceptance of this modality, as it is significantly higher with CBCT than with conventional radiographs. Most modern machines offer options to decrease the field of view (FOV) and exposure time, which along with proper patient shielding can markedly decrease the radiation exposure to the patient.4 Orthodontists should adhere to the ALARA principle (As Low As Reasonably Achievable) and measure the individual benefits vs. risks for each patient. In routine orthognathic surgical cases, CBCT has improved pre-surgical planning and splint fabri- 14 PCSO Bulletin  Summer 2015

Table of Contents for the Digital Edition of Pacific Coast Society of Orthodontists Bulletin Summer 2015

Staying Connected in a Large, Diverse Orgainziation
Palm Springs: A PCSO Favorite
Trustee Report
PCSO at a Glance
PCSO Member News
AAOF Report
Special Section on CBCT
CBCT Imaging Protocols Within PCSO Residency Programs
Cone-Beam Computed Tomography in Orthodontics - Benefits of Comprehensive Visualization
Case Report Pre-Treatment
CBCT in Today's Orthodontic Practice
Case Report Post-Treatment
Differentiating Posterior Crossbites with CBCT Volumetric Images
Apps for the Orthodontist
Dr. Ib Leth Nielsen, San Francisco, CA
Dr. Robert J. Bendzak
Dr. Arthur A. Dugoni's 90th Birthday Makes for a Special Alumni Meeting in San Francisco
Preparing for the Unexpected: Your Emotional SOS Plan, Part II
Resident Spotlight
Hygiene: A New Battle for an Old War
Dr. Peter Picard, 1919-2013

Pacific Coast Society of Orthodontists Bulletin Summer 2015