The mimetic muscles (Fig 9-2) can be grouped into upper face muscles and lower face muscles.
The upper face muscles include
the corrugator supercilii (oblique and transverse heads) (Fig 9-3), depressor supercilii, and procerus muscles, which animate the glabella and medial eyebrow and cause vertical and oblique rhytids
the orbicularis oculi muscle, which depresses the eyebrows and closes the eyelids
the frontalis, which is the sole elevator of the eyebrows; contraction of this muscle causes transverse forehead rhytids
The lower face muscles include
the superficial mimetic muscles, which receive their neurovascular supply on the posterior surfaces and include the platysma, zygomaticus major, zygomaticus minor, and risorius
the deep mimetic muscles, which receive their neurovascular supply anteriorly and include the buccinator, mentalis, and levator anguli oris
Other facial muscles include the orbicularis oris, the levator labii superioris, the levator labii superioris alaeque nasi, the depressor anguli oris, the depressor labii inferioris, the masseter, the nasalis, and the temporalis.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.