Hyoid Arch Muscles

The hyoid arch muscles (HAMs) are part of the branchiomeric craniofacial muscles which control feeding, breathing and facial expression. These muscles originate in the pharyngeal mesoderm and are characterized by a genetic program similar to that of the adjacent second heart field, progenitor cells which gives rise to the majority of the heart. The cranial paraxial mesoderm and head lateral (splanchnic) mesoderm cells heavily contribute to formation of these muscles. Hyoid arch muscles anlagen eventually split, via an unidentified mechanism, to form lower  facial muscles:mandibular depressors, stapedial muscle and facial expression muscles.