Atypical Anatomy: Tips on What to Look for in CBCT Data

While most of the scans you read will fall into the “normal anatomy” category, the logical next step in the journey of learning how to interpret data sets from cone beam computed tomography (CBCT) imaging is developing proficiency at deciphering anatomical variations. These variations can often be seen in intraoral and extraoral radiography, and it is sometimes helpful to use 3D radiography to fully understand certain variations; which otherwise could result in failure to diagnose.

One of the most common anatomical variations of a critical structure is the anterior extension/loop of the inferior alveolar nerve. Visualizing this structure is imperative when planning surgical procedures in the anatomical areas around mental foramen and the immediate area anterior to it.

Anterior extension of Inferior Alveolar canal: the red circle shows anterior extension and the yellow circle shows mental foramen

In addition to mental foramen, accessory foramen(s) can also be noted as a variation of normal anatomy in the mandible.

The temperomandibular joint (TMJ) area can exhibit wide variations in normal anatomy, which has to be correlated with clinical findings and additional imaging if necessary to establish the absence of any pathology. One of the most common variations can be the inter-articular space of the joint. This space may vary widely between contralateral joints of the same patient and between patients as well. The complexity of this anatomical region warrants a thorough review of all information available. Continue reading

The Importance of Knowing Normal Anatomy in CBCT Scans

The acquisition of CBCT scans is probably one of the most mundane tasks, but it is an important part of the imaging process. Post-acquisition involves viewing and interpreting the scans. Although the maxillofacial region is complex, by virtue of familiarity, most dentists can interpret this area very efficiently despite the complex nature of anatomy and variances in this region. Understanding what is considered normal is the first step to identifying abnormalities that could pose a challenge in the treatment planning.

Normal anatomy can be broadly divided into the maxillary and mandibular regions.

When visualized, the upper regional anatomy is comprised of (but not limited to) the bilateral maxilla, as well as the nerves and vascular supply of the region and the maxillary sinus and other paranasal sinuses (in part or full, depending on the field of view). Along with these areas, the, Osteomeatal complex and orbits are the most significant.

Maxilla- Coronal View of Bilateral Maxillary Sinus

Maxilla- Coronal View of Bilateral Maxillary Sinus

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CBCT and Accreditation

As dental professionals learn more about the many clinical uses of cone beam computed technology (CBCT) and the benefits of having an in-office system provides, the popularity of 3D imaging systems is growing—and with that, so are the requirements for accreditation. At the moment, the number of practices required to have CBCT accreditation is limited. Currently, it’s only necessary in situations where:

  •  the practice receives reimbursements for Medicare or Medicaid;
  • the practice is located in Minnesota; or
  • the practice is located in California.

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Three Dimensional Basics: Pixels and Voxels

Most of us are already familiar with pixels; after all, one of the first questions that we may ask when picking out a digital camera or computer monitor is how many pixels it has.  When it comes to digital radiography, the pixels still apply, but are limited to two dimensional images, such as intraoral and extraoral radiographs. In three-dimensional radiography, such as CBCT imaging, the complimentary unit is referred to as voxel. Continue reading

Three-Dimensional Basics: CT vs. CBCT

While speaking with my colleagues—and even patients—about 3D imaging, I am sometimes questioned about the difference between computed tomography (CT) and cone-beam computed tomography (CBCT).  Since we are in the beginning stages of our series on 3D, I thought this would be a great time to compare the two technologies and discuss the benefits of incorporating CBCT into your practice. Continue reading

Three-Dimensional Basics: What’s the Difference between 2D and 3D Technology?

Whether it is in printing or imaging technology, 3D seems to be a frequently spoken of topic for many us. As an Oral and Maxillofacial radiologist, I certainly have my own opinions on the matter, and I am often asked to share them with my peers when speaking at conferences and seminars across the nation. To that end, I would like to tackle this topic in depth by covering every aspect of 3D—including what makes it different from 2D digital dental technology.

Although 3D imaging shouldn’t be used as a primary choice without analyzing the risks vs. benefits to patients, incorporating a 3D imaging system into your practice could provide several benefits, including:

  • Improved diagnoses and treatment planning – enhanced images allow you to see more than you can with 2D alone
  • Better patient communication – patients are more likely to comprehend with their diagnosis when the clinician can point out the problem on a more realistic 3D image rather than a static 2D image
  • Increased case acceptance – 3D imaging software allows you to map out treatment plans so patients can make better-informed decisions regarding their proposed treatment plan

Differences between 2D and 3D Images

While 2D radiographs are a static image taken of a specific area of interest, 3D imaging uses rotating cone shaped beams of X-rays to take images that are then reconstructed to form multiplanar images, cross sectionals and 3D surface renderings that have much higher sensitivity in diagnosing pathology. To break down the biggest differences between these two imaging forms, I created the table below:

Categories 2D Imaging 3D Imaging
Images Flat Image MPR & Cross-sectional images made up of multiple thin slices
Distinction of Structures Anatomical Structures are overlapped (superimpositions) Isolated visualization of structures
Clarity Distortions are possible Anatomical accuracy can be achieved
Image Manipulation Single image for manipulation DICOM stacks available for manipulation


The underlying theme when it comes to the differences between 2D imaging and 3D imaging is that 3D technology allows dental specialists to uncover critical information that could be subdued while 2D imaging is solely relied upon.

Have you incorporated 3D imaging into your practice yet? If so, what advice would you give others who are interested in this technology?