Labrale superius and inferius: vermilion border points
Quick facts
- Definition
- Points on the free border of the vermilion: the labrale superius on the upper lip, the inferius on the lower lip.
- Abbreviation
- Ls (labrale superius) and Li (labrale inferius).
- Use
- Measuring the proportion between the lips and their position relative to profile lines.
- Difference
- They are measurement points; the vermilion is the structure they help describe.
The labrale superius (Ls) and labrale inferius (Li) are reference points on the border of the lip vermilion. The upper one sits at the center of the upper lip and the lower one at the center of the lower lip. Because they are points, not structures, they are used to measure and compare.
What are they for?
With these points you can calculate the lip proportion and assess the position of the lips relative to profile lines, such as Ricketts' E-line and Steiner's S-line. The reading is done on the profile photo or the cephalometric tracing, within facial anthropometry.
| Point | Where it sits | Use |
|---|---|---|
| Labrale superius | Center of the upper lip border | Position of the upper lip in profile |
| Labrale inferius | Center of the lower lip border | Position of the lower lip in profile |
How does this show up in the clinic?
More as planning language than as conversation with the patient. When assessing a thin or projected lip, the professional can use these points to get numbers and track progress, without relying on the eye alone. Other landmarks of the area, such as the Cupid's bow, complete the reading. See also thin lips: assessment.
Frequently asked questions
What is the labrale superius?
It is the reference point at the center of the border of the upper lip, at the transition between the vermilion and the skin. The labrale inferius is the equivalent point at the center of the lower lip.