Human lips with the vermilion border outlined. A patch of
erythema above the upper lip makes it more difficult to distinguish the vermilion border.
This left cheek incision extends from the left
commissure towards the left
ear and it breaches the vermilion border (click to see close-up). In order to maintain
aesthetics as best possible, the first
suture was placed at or near the vermilion border to ensure a
contiguous line upon healing.
The vermilion border (sometimes spelled vermillion border), also called margin or zone, is the normally sharp demarcation between the
lip and the adjacent normal
skin. It represents the change in the
epidermis from highly
keratinized external skin to less keratinized internal skin. It has no
sebaceous glands,
sweat glands, or
facial hair.[1][2]
It has a prominence on the face, creating a focus for
cosmetics (it is where
lipstick is sometimes applied) and is also a location for several skin diseases. Its functional properties, however, remain unknown.[3]
Structure
The lips are composed wholly of soft tissue. The skin of the face is thicker than the skin overlying the lips where blood vessels are closer to the surface. As a consequence, the margin of the lips shows a transition between the thicker and thinner skin, represented by the vermilion border. It therefore has the appearance of a sharp line between the coloured edge of the lip and adjoining skin.[4]
It has been described as a pale, white rolled border and also as being a red line.[1][5]
This fine line of pale skin accentuates the colour difference between the
vermilion and normal skin. Along the upper lip, two adjacent elevations of the vermilion border form the
Cupid's bow.[6]
There are two reasons that the border appears red in some people:
The epithelium is thin and therefore the blood vessels are closer to the surface.[7]
This epithelium contains
eleidin which is transparent and the blood vessels are near the surface of the papillary layer, revealing the "red blood cell" color. At the angles of the mouth, there are sebaceous glands, without hair follicles, which are called
Fordyce spots.[2][8]
Perioral dermatitis is a rash typically around the mouth, that spares the vermilion border.[10]
Cheilitis glandularis may present with a burning sensation over the vermilion border. This chronic progressive condition is associated with thinning of the skin of the lips and ulceration.[11]
Infections may involve the vermilion border.
Cold sores are one common infection.[12]Impetigo is another.[13]
Fetal alcohol syndrome causes facial abnormalities which include a thin vermilion border with a smooth philtrum.[14]
Cosmetic appearance
Sunlight exposure can blur the junction between the vermilion border and the skin. Applying
lip balm and
sunscreen moisturizes protects it from sunlight.[15]
Surgery
A vermilionectomy (sometimes spelled vermillionectomy) is the surgical removal of the vermilion border. It is sometimes performed to treat
carcinoma of the lip.[16]
Close attention is given when repairing any injury to the vermilion border. Even 1 mm of vermilion misalignment could be noticeable.[5]
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abcChiego, Daniel J. (2018).
"14. Oral mucosa". Essentials of Oral Histology and Embryology: A Clinical Approach. Elsevier. p. 170.
ISBN9780323569323.