Finding the right tests…
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Finding the right tests…
X-Ray
A lateral cephalogram is a side-on X-ray of your skull taken with your head held steady in a fixed frame, called a cephalostat, with rods resting in each ear canal. This positioning sets it apart from an ordinary skull X-ray: it lets an orthodontist take the same measurements on every patient and compare them against known averages. The film shows the profile of your jaw bones, front teeth, and the soft tissue outline of your face in one image. Orthodontists use it to plan braces or jaw alignment treatment, tracing points on the bone and teeth to calculate angles between the jaws and skull base. It is a planning tool, not a diagnosis on its own.
The film is traced for specific points on the jawbones, skull base, and front teeth, then used to calculate angles that describe how your upper and lower jaw relate to each other and to your skull. Your orthodontist compares these angles against typical ranges to plan tooth movement or jaw treatment.
Unlike a regular skull X-ray, a lateral cephalogram is taken to strict, repeatable rules. Your head sits in a frame with rods in each ear canal, positioned so an imaginary line from ear to the bottom of the eye socket runs level, and the X-ray source stays a fixed distance away. This consistency is what lets an orthodontist compare your film against standard reference values, and against your own film from an earlier visit.
Orthodontists use the film to work out where your upper and lower jaws sit relative to your skull base, and where your front teeth sit relative to the jawbone supporting them. This shapes decisions about whether braces alone will work, or whether jaw surgery needs to be part of the plan.
- A single 2D film can show incisor angle and general bone thickness, but research comparing it with 3D imaging has found it tends to overstate the bone around front teeth - Not every orthodontic patient needs one; it is generally reserved for cases where jaw or incisor position could meaningfully change the treatment plan - The measurements are only as useful as the reference values they are compared to, and your orthodontist should walk you through what your results mean rather than leaving you to read the angle numbers alone
No. It uses a fixed head frame and ear rods so the same measurements can be taken and compared reliably, which a routine skull X-ray does not allow for. Both are side-view X-rays, but only the cephalogram is standardised this way.
No, it is generally reserved for cases where jaw or front-tooth position could change the treatment plan, such as before jaw surgery or significant tooth movement. Your orthodontist will explain if your case needs one.
It provides measurements that help your orthodontist judge whether braces alone can achieve the needed change, or whether surgery should be considered. The final decision also depends on your exam and other findings.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
The ear rods hold your head in a fixed, repeatable position so the film can be measured accurately and compared against standard values or your own earlier films. It only takes a moment to position.
Some orthodontic plans include a repeat film partway through or at the end of treatment to check progress, while others need only one at the start. Ask your orthodontist what your plan involves.
It gives a useful two-dimensional estimate, but research shows it can overstate bone thickness around the front teeth compared with 3D imaging. Your orthodontist factors this into planning.
The dose from a single film is low, similar to other dental and skull X-rays. Tell your orthodontist if you are pregnant, or if you have had several skull or dental X-rays recently.