Muscles of Mastication Medical Therapeutics Ms. Taylor

Did You know….. Muscles in and around your mouth facilitate the mastication or chewing process.

Glossary deglution: swallowing mastication: chewing origin: muscle attachment site on the bone insertion: the muscle attachment site that has the greatest amount of movement during contraction action: the description of movement of the muscle palpate: to feel or touch with fingers or hands Bilateral: both side or equally affecting both sides protrude: to extend in an outwards or forward motion lateral: the side of the body or a body part that is farther from the middle or center of the body

Masseter Temporal Medial Ptyergoid Lateral PTyergoid There are four main muscles to help you masticate (chew) They work together to move the mandible. Masseter Temporal Medial Ptyergoid Lateral PTyergoid

Masseter. Action: bilateral contraction elevates mandible, clenches teeth The masseter is the most powerful palpable muscle of the mouth. Insertion: superficial head inserts on lateral surface of the angle and the deep head inserts on ramus above the angle

Temporal Action: elevate mandible, retract mandible Temporal Origin: temporal fossa. Insertion: anterior border of coronoid process and anterior border of ramus.

Medial pterygoid Action: elevates mandible, protracts and opens the mandible Origin: pterygoid fossa on medial surface of lateral pterygoid plate. Insertion: medial surface of angle of mandible.

Insertion: anterior surface of neck of mandibular condyle. Lateral pterygoid Action: inferior portion depresses mandible, its main action is when both muscles contract bringing the lower jaw forward. If only one lateral pterygoid muscle contracted, lower jaw shifts to opposite side and it also closes the mandible. Insertion: anterior surface of neck of mandibular condyle.

Accessory muscles of mastication There are two sets of accessory muscles that aid in mastication. Suprahyoid and infrahyoid muscles suprahyoid muscles help to raise the floor of the mouth, the larynx and the hyoid bone during deglution (swallowing). infrahyoid muscles help to depress the hyoid bone during swallowing and speech

Suprahyoid Muscles

Infrahyoid muscles

Obicularis Oris: encircles the mouth, allows the lips to control most movements of the lips. Mentalis: raises the chin and pushes up the lower lip Platysmus: lowers the bottom lip and pulls the angle of the chin down and to the side buccinator: compresses the cheek against the teeth and retracts the angle of the mouth

Work sheet to print out… it does not show the ptyergoid muscles though

Work sheet to print out for class

Answer key for work sheet

Dorsal surface of tongue

Enlarged papillae Circumvallate are large and are formed at the base of the tongue. Their primary role are taste. Filliform are small cone like projections in front of the circumvallate papillae Fungiform These are flattened papillae found on the top and sides of the tongue Foliate papillae are a series of folds on the sides of the tongue close to the back of the tongue