Overview
Three-dimensional Cone Beam Computed Tomography (CBCT) images have a wide range of diagnostic and treatment planning uses, and are quickly becoming a standard-of-care practice in implant planning, providing information that traditional 2-D radiographic images simply cannot. Using an illustrative case report, Dr. James Jesse describes how the latest CBCT technology enables dentists to better understand patient anatomy, thus producing safer, more predictable treatment outcomes.
James Jesse, DDS
Dr. James Jesse graduated from Loma Linda University in 1973 and has been in private practice in Colton, Calif., for 34 years. An associate professor of restorative dentistry at LLU and an assistant professor of restorative dentistry at Columbia University, he is involved in research at both universities. Formerly a member of the executive board of the World Clinical Laser Institute and editorial board of Ascend Media, Dr. Jesse lectures nationally and internationally, and is a member of the ADA, AOD and AGD. Contact him at inclusivemagazine@glidewelldental.com.
Implant and Mandibular Canal Mapping
As the saying goes, "The only constant in life
is change." This is certainly true of the dental industry, as emerging technologies continue to transform the everyday methods clinicians use to treat their patients. Fortunately, the purpose of these technologies is to improve the quality of care by making treatments safer, more accurate, more efficient and more cost-effective overall. Whatever the short-term cost in terms of monetary or educational investment, the long-term adoption of new technologies is designed to better our lives as dentists, and those of our patients.
In the diagnostic realm of dentistry, the X-ray has evolved from 30-plus seconds of exposure to digital, where the exposure is fractions of a second. We have seen the panographic films change to digital, showing better detail and clarity. It is logical to now include 3-D imaging into the dental practice. With traditional 2-D images, the dental practitioner is limited to what information can be seen in that dimension, i.e. buccal-lingual views from panoramic, periapical and bitewing X-rays. With 3-D imaging, we now can open the door and examine dental anatomy from any direction or angle, which gives us much more accurate information before we even begin treatment, enabling us to continually improve the quality of our work.
Three-dimensional Cone Beam Computed Tomography (CBCT) images have a wide range of diagnostic and treatment planning uses, including general dentistry, TMJ analysis, airway studies (snoring and sleep apnea), jaw and other tumors, impacted teeth, periodontal disease, endodontic anomalies, and oral surgery. One area in which 3-D CBCT images are quickly becoming a standard-of-care practice is in implant planning.
Case Report
In April 2011, a 55-year-old patient with a lifelong history of serious dental problems presented for a dental implant in the area of tooth #29. Due to this patient's history, it was critical to fully understand her anatomy – the location of her mandibular canal and mental foramina, bone structure and bone density – to verify that she had sufficient bone to support an implant. A 3-D CBCT scan was taken using the PreXion 3D CBCT dental scanner (PreXion Inc.; San Mateo, Calif.) and a thorough evaluation performed. The first step in this evaluation was to examine the panographic image produced by the CBCT system to get an overall perspective of the patient's anatomy (Fig. 1).
A more comprehensive examination was performed using the multiplanar reconstruction (MPR) and three-dimensional views. In the sagittal (side) view, the mandibular canal was easily identified and mapped to pinpoint its precise location and avoid potential problems (Fig. 2). Measurements were taken to determine the vertical distance from the ridge crest to the nerve below, thereby determining the maximum length of implant that could be used while allowing for sufficient margin to avoid hitting or damaging the alveolar nerve (Fig. 3). Bone density was also measured and found to be in good condition where the implant was to be anchored. The examination was continued in the coronal view (front to back), and additional measurements were taken to determine the bone width and also to reaffirm the distance from the ridge to the mandibular canal (Fig. 4).
It was determined from these highly accurate images and measurements that there was sufficient bone and bone density to allow for placement of a 3.75 x 13 mm implant and still have a 3 mm-plus margin for error. The CBCT images also revealed that tooth #31 was cracked, and thus this tooth was extracted prior to implant placement.
Conclusion
A few months postoperative, a follow-up CBCT scan was conducted and measurements taken to confirm proper implant placement and osseointegration (Fig. 5, Fig. 6).
The advent of affordable, high-quality 3-D CBCT systems in dentistry has definitely improved our ability to better and more accurately diagnose and treatment plan. While there are significant financial benefits to having a cone beam system in your practice, more critical is the quality and quantity of information provided to us by these systems. These 3-D CBCT systems allow us to confidently know and understand our patients' anatomy and to identify potential complications before we begin treatment, thus producing safer, more predictable outcomes.
