Cephalometry: measurements from the head X-ray

Cephalometry is the analysis of measurements made on the lateral cephalometric X-ray of the head. On the image, the professional marks bony points, such as the nasion and the pogonion, draws planes and calculates angles and distances. Orthodontics and orthognathic surgery have used this method for decades to describe the relationship between maxilla, mandible and skull.

What are the lines and angles for?

Each analysis has its own name and author. The Steiner, Ricketts and Holdaway lines compare the position of the lips and chin with a reference, while the facial convexity angle describes the profile as straight, convex or concave. The Frankfurt plane standardizes head position in the measurements.

Reference values vary by author, ethnicity, age and sex. A number outside the average is not, by itself, a defect.

Where does HOF meet cephalometry?

When the patient arrives with a concern about a small chin, a convex profile or lips that look closed, the exam can show whether the origin is skeletal. If the cause is the bony base, dermal filler improves the soft tissue contour but does not change the bone. This helps explain to the patient what to expect and when an assessment by the orthodontist or the surgeon is more appropriate.

What is the limit of the method?

Cephalometry is two-dimensional and static. It does not show expression, the smile, soft tissue volume in motion or the patient's perception of beauty. Clinical facial analysis remains central, with standardized frontal and profile photos.

In Harmy

Harmy uses only the frontal photo and does not take cephalometric measurements or project the profile. Profile and X-ray stay with the professional's clinical assessment.