MUSCLE

ORIGIN

INSERTION

ACTION

INNERVATION

Digastric

• Digastric notch,
• medial surface of base of mastoid process

• Digastric fossa

• Depress the mandible

• Posterior belly: facial nerve
• Anterior belly:nerve to mylohyoid

Stylohyoid

• Back of styloid process near the base of skull

• By two slips into the junction between the greater horn and body of hyoid bone

• ELevate hyoid bone

• Facial nerve

Mylohyoid

• Whole length of mylohyoid line of its own side on the inner aspect of the mandible from medial to the third molar tooth to below the mental spines

• Anterior ¾: into each other (interdigitation)
• Posterior ¼: anterior surface of the body of hyoid bone

• Forms a mobile but stable floor of the mouth

• Mylohyoid nerve

Geniohyoid

• Inferior mental spine

• Upper border of the body of hyoid bone.

• Protracts and elevates the hyoid bone in swallowing or if the hyoid is fixed to depresses the mandible.

• C1(superior root of ansa cervicalis)