Chapter 2C: Diagnostic Tools Explained

At various points across all three stages, your orthodontist may use one or more diagnostic tools to plan treatment. Understanding what each one actually shows can make these visits feel considerably less mysterious.

Panoramic X-ray

A single, wide X-ray image capturing the entire upper and lower jaw in one flat picture, including unerupted teeth still developing beneath the gums. This is typically the first imaging tool used, since it gives a broad overview of tooth positions, missing or extra teeth, and overall jaw structure with a very low radiation dose.

Cephalometric X-ray

A standardized side-profile X-ray of the head, used to measure the relationship between the upper jaw, lower jaw, and skull base. This is the image used to assess jaw growth patterns and plan functional appliance therapy or comprehensive treatment involving jaw relationships, not just individual teeth.

3D Cone-Beam CT (Used Selectively)

A more detailed three-dimensional scan, used selectively rather than routinely, typically reserved for complex cases such as impacted teeth, suspected airway concerns, or surgical planning, given its higher radiation dose compared to a standard panoramic X-ray.

Digital Intraoral Scans and Photographs

Increasingly common in place of traditional putty impressions, a digital scanner captures a precise 3D model of the teeth in a few minutes, used both for diagnosis and for planning and fabricating aligners or other custom appliances. Standardized photographs of the face and smile are also typically taken at the start of treatment and at intervals throughout, to document progress.

Hand-Wrist X-ray (Used Selectively)

Occasionally used to estimate a child's remaining growth potential by examining bone development in the hand and wrist, which follows a well-studied maturation pattern. This is sometimes used to help time functional appliance therapy relative to a child's individual growth spurt, discussed in Chapter 1, though not every practice uses this tool routinely.

None of these tools are used simply for the sake of using them — each answers a specific planning question. It's entirely reasonable to ask what specific question a given X-ray or scan is meant to answer before agreeing to it.