Why Consider CBCT — Part 2: A Guided Approach to Orthodontic Treatment and Airway Health

By Jeffrey Dahm, DDS, and Ross Johnson, DDS, MSD

Editor’s Note: This article is the second installment in a two-part series beginning with “Why Consider CBCT?” in the Fall 2025 issue of JAOS.

The radiographic foundation of orthodontics has been rooted in panoramic and cephalometric imaging for decades. Airway evaluations were once limited to looking at the patient clinically and making a measurement in the sagittal plane on cephalometric images. Many orthodontic texts mention that the airway is involved with malocclusions but fail to dive deeper into the topic. Now, we have 3D technology that opens a new way of looking at structures within the head and neck, including the upper airway.

Cone-beam computed tomography (CBCT) was developed in the mid-1990s and became available for clinical use in the early 2000s. Still, the technology remains relatively new, and more work is needed to understand how we can use it to explore the airway component of malocclusions and determine better paths for treatment.

Two-dimensional cephalometric images are not identical to the images rendered via CBCT. A 2D ceph has overlapping structures, can be difficult to distinguish between left and right sides, and suffers from magnification error (the projected image farthest from the sensor appears larger). In other words, images taken in norma lateralis will show the patient’s right-side mandibular corpus larger than the left because the right mandibular corpus is farther from the sensor. With CBCT technology, the cephalometric image is represented as a slice of a predetermined thickness located at midline structures. The CBCT-generated cephalogram has an aspect ratio of 1:1 (Fig. 1).¹