Modiolus of angulus oris

The modiolus of angulus oris is a fibromuscular node (or chiasma) located at the angle of the mouth (angulus oris). It serves as an important converging point for several muscles of facial expression, making it a key structure in oral and perioral movements.

Location

The modiolus is situated lateral and slightly superior to the angle of the mouth. It lies superficial to the buccinator muscle and anterior to the masseter muscle.

Muscular attachments

Several muscles of facial expression interlace at the modiolus, including:

• Orbicularis oris (encircles the mouth),

• Buccinator (from the cheek),

• Levator labii superioris

• Zygomaticus major

• Levator anguli oris,

• Risorius,

• Depressor anguli oris,

• Platysma (occasionally contributes), .

Innervation

Motor nerve supply from the facial nerve.

Vasculature

Blood supply from labial branches of the facial artery.