The depressor anguli oris muscle receives its blood supply from a branch of the facial artery.

The depressor anguli oris muscle is supplied by the marginal mandibular branch of the facial nerve.

[1] Damage to the marginal mandibular branch of the facial nerve may cause paralysis of the depressor anguli oris muscle.

[1] This may be corrected by resecting (cutting and removing) the depressor labii inferioris muscle, which has a more significant impact on smiling.

[1] Underdevelopment (hypoplasia) or complete absence (aplasia) of the depressor anguli oris can occur.