Cone Beam Computed Tomography:

What is a CBCT? And why is it important for comprehensive diagnosis?

Cone beam computed tomography (or CBCT, C-arm CT, cone beam volume CT, or flat panel CT) is a medical imaging technique consisting of X-ray computed tomography where the X-rays are divergent, forming a cone. [i]

CBCT has become increasingly important in treatment planning and diagnosis in implant dentistry, ENT, orthopedics, and interventional radiology (IR), among other things. Perhaps because of the increased access to such technology, CBCT scanners are now finding many uses in dentistry, such as in the fields of oral surgeryendodontics and orthodontics. Integrated CBCT is also an important tool for patient positioning and verification in image-guided radiation therapy (IGRT).

During dental/orthodontic imaging, the CBCT scanner rotates around the patient's head, obtaining up to nearly 600 distinct images. The scanning software collects the data and reconstructs a 3D image of the target region, which in dentistry, is typically focused on the head and neck regions of anatomy. CBCT has been described as the gold standard for imaging the oral and maxillofacial area.

We use CBCT technology to allow us to view, understand, and potentially diagnose a variety of biological, anatomical, and pathological conditions that otherwise could go undetected from typical 2D dental radiographs and clinical exams. These conditions include but are not limited to:

  • Boney defects such as cavitations and periodontal disease

  • Fractured teeth & roots of teeth

  • Soft tissue positioning, more specifically adenoids and airway

  • Root canal treated teeth and the surround bone

  • Sinuses
     

In order to prevent or treat the root cause of dental and oral health disease, it is imperative to that we have “the whole picture” of what is going on to ensure we can fully educate our patient(s) and set them up for success in the form of stable oral health and optimized systemic wellness.

 

Specific to the airway, what are we evaluating?

Restricted Airway

Pictured above are examples from two different children: one with a restricted airway, and another with a wider, more voluminous airway. Restricted airways can be due  to any of the following issues:

  • A retrusive (or posterior) positioning of the mandible

  • A mandible and/or maxilla (the “bottom and top jaws”) being too small

  • Large or inflamed tonsils and/or adenoids

  • Poor oral habits (ie. inability to breathe through the nose, finger or thumb sucking)

  • Poor or improper position of the tongue

 

For further evaluation, this CBCT demonstrates the restriction, or “pinching”, of the airway that occurs as a result from mouth breathing.

Open, Healthier Airway

What happens if the jaw is not positioned correctly?

If left undiagnosed and therefore unaddressed and untreated, an adult can end up with “straight teeth”, but a severely compromised airway and TMJ. This is why so many adults today have a “pretty smile” but are riddled with chronic conditions such as sleep-disordered breathing (i.e. snoring, obstructive sleep apnea, etc.) and TMJ disorder. However, in all of our cases, we are evaluating the position of the mandible first to ensure that a healthy airway and TMJ position are supported, and only after that is stabilized do we reposition the teeth to stabilize this optimal position.

 

Below is an example of an adult who experiences chronic inflammatory symptoms such as allergies, dark circles under the eyes, restless sleep, teeth grinding, and morning headaches. This patient was treated with braces as a pre-teen but never had her airway or TMJ evaluated. As a result, she was left in this compromised for her entire adult life where she is essentially breathing through a coffee straw instead of more of a garden hose. We are able to treat adults like this to improve their quality of life, but it is much easier to “prevent” this condition with early interventional therapy when a child is growing and developing as early as 2 yrs old up until they reach puberty.

Adult case treated with traditional braces to achieve “straight teeth” but left with a compromised airway, sleep disturbances, and symptomatic airway.

Want to be screened for airway issues, cavitations, boney defects, & other pathologies?
  1. Technical Description of CBCT from University of Manchester. Citing: Scarfe WC, Farman AG, Sukovic P (February 2006). "Clinical applications of cone-beam computed tomography in dental practice". Journal of the Canadian Dental Association. 72 (1): 75–80. PMID 16480609.