Medical Term for the Upper Lip
The medical term for the upper lip is labium superius oris (or simply "upper lip" in clinical practice), with key anatomical landmarks including the vermilion (the red-pink portion), the vermilion border (the junction between the vermilion and surrounding skin), the philtrum (the vertical groove in the midline), Cupid's bow (the double curve at the upper vermilion border), and the white roll (the ridge at the vermilion-cutaneous border) 1, 2, 3.
Key Anatomical Components
Structural Landmarks
- Vermilion: The red-pink mucosal portion of the lip that is visible externally 1, 2, 3
- Vermilion border: The critical junction between the vermilion and the cutaneous (skin) portion of the lip, which must be precisely aligned during any surgical repair to avoid aesthetic deformity 1, 2
- Philtrum: The vertical midline groove extending from the base of the nose to Cupid's bow, formed by the intersection of superficial reticular muscle fibers 4
- Cupid's bow: The distinctive double-curved contour of the upper vermilion border, shaped by the levator labii superioris alaeque nasi, levator labii superioris, and zygomaticus minor muscles 4
- White roll: The subtle ridge at the vermilion-cutaneous border that can be particularly challenging to restore during reconstruction 2
Muscular Anatomy
- Orbicularis oris muscle: The primary circular muscle of the lip, consisting of superficial and deep layers that are critical for lip function and animation 5, 4
- The deep layer contains fan-shaped muscle fibers that incline inward, with some ending at the anterior nasal crest 4
- Multiple insertion points exist for animation muscles, including the upper lip dermis, orbicularis oris, and modiolus 5
Vascular Supply
- Superior labial artery: A branch of the facial artery that supplies the upper lip, typically running along the vermilion border at a depth of approximately 3 mm 6
- The artery originates approximately 12.1 ± 3.1 mm lateral to the mouth corner and proceeds along the vermilion border to the facial midline 6
- The artery can be located in submucosal (78.1%), intramuscular (17.5%), or subcutaneous (2.1%) positions relative to the orbicularis oris muscle 7
Clinical Significance
Functional Importance
The upper lip's primary role is coverage of dentition and animation, distinguishing it from the lower lip which is more critical for oral competence, speech, and eating 5. The orbicularis oris and several other muscles contribute to upper lip function through various insertion points 5.
Surgical Considerations
Special attention must be paid to the philtrum, Cupid's bow, and vermilion border during any reconstruction or repair, as distortion can result in significant functional and aesthetic impairment 2, 5. Scars should be placed along natural boundaries when possible, such as the vermilion border or philtral columns 2.