[1] Its medial fibers form the angular head (also known as the levator labii superioris alaeque nasi muscle[2]) which arises by a pointed extremity from the upper part of the frontal process of the maxilla and passing obliquely downward and lateralward divides into two slips.

One of these is inserted into the greater alar cartilage and skin of the nose; the other is prolonged into the lateral part of the upper lip, blending with the infraorbital head and with the orbicularis oris.

Its fibers converge, to be inserted into the muscular substance of the upper lip between the angular head and the levator anguli oris.

The lateral fibers, forming the zygomatic head (also known as the zygomaticus minor muscle[3]) arise from the malar surface of the zygomatic bone immediately behind the zygomaticomaxillary suture and pass downward and medialward to the upper lip.

[4] This article incorporates text in the public domain from page 383 of the 20th edition of Gray's Anatomy (1918)