Main Model
Nasal Cavity, Cavity of Pharynx and Oral Cavity : g Orbicularis oris
Muscle: Orbicularis oris (Oral sphincter)
Origin: Medial maxilla and mandible; deep surface of peri-oral skin; angle of mouth (modiolus)
Insertion: Mucous membrane of lips
Main Action(s): Tonus closes oral fissure; phasic contraction compresses and protrudes lips (kissing) or resists distension (when blowing)