The orbicularis oris is a superficial facial muscle with fibers that encircle the opening of the oral cavity that attaches to the maxilla, mandible, skin and modiolus, and that participates in oral/pharyngeal behaviors, and is innervated by the facial nerve (CN VII). [ https://doi.org/10.1002/ar.21355 https://doi.org/10.1111/j.1469-7580.2009.01111.x http://www.feedexp.org/wiki/Mammalian_Muscle_Ontology_Workshop ]