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    Related Topics

    From Musculoskeletal System

    Masseter
    Muscle that elevates the mandible.
    Clavicle
    Collarbone connecting the arm to the body.
    Sternum
    Breastbone located in the center of the chest.
    Gomphoses
    Fibrous joints where a peg fits into a socket (e.g., teeth in jaw).
    Lacrimal Bones
    Bones forming part of the eye socket and housing the tear ducts.
    Coccyx
    Tailbone, the remnant of the tail in humans.
    Ulna
    Forearm bone on the pinky side.
    Occipital Bone
    Bone forming the back and base of the skull.
    Thoracic Vertebrae (T1 - T12)
    Vertebrae in the upper and mid-back (T1-T12).
    Lumbar Vertebrae (L1 - L5)
    Vertebrae in the lower back (L1-L5).
    Deltoid
    Shoulder muscle responsible for arm abduction.
    Scapula
    Shoulder blade providing attachment for muscles of the upper limb.
    Diaphragm
    Primary muscle for breathing.
    Metatarsals (5 bones)
    5 bones forming the mid-foot.
    Lateral Collateral Ligament (LCL)
    Knee ligament that stabilizes the outer knee.
    Anterior Cruciate Ligament (ACL)
    Knee ligament that stabilizes the joint.
    Coccygeus
    Pelvic floor muscle supporting the coccyx.
    Posterior Longitudinal Ligament
    Spinal ligament running along the back of the vertebral column.
    Sartorius
    Longest muscle in the body responsible for hip flexion.
    Sacrum
    Triangular bone at the base of the spine.
    Biceps Tendon
    Tendon that attaches the biceps muscle to the bone.
    Carpals (8 bones)
    8 wrist bones.
    Levator Ani
    Pelvic floor muscle responsible for lifting the anus.
    Mandible
    Lower jawbone that houses the teeth.
    Inferior Nasal Conchae
    Bones inside the nasal cavity that filter and humidify air.

    Temporalis

    Reviewed by our medical team

    Muscle involved in closing the jaw.

    1. Overview

    The temporalis is a broad, fan-shaped muscle located on the side of the head. It is one of the primary muscles of mastication (chewing) and plays a major role in elevating and retracting the mandible (lower jaw). As a powerful and efficient jaw closer, the temporalis is essential for biting and grinding food.

    2. Location

    The temporalis muscle is located in the temporal fossa of the skull:

    • Origin: Temporal fossa and deep surface of the temporal fascia.

    • Course: Fibers converge downward, passing deep to the zygomatic arch (cheekbone).

    • Insertion: Coronoid process of the mandible and the anterior border of the mandibular ramus.

    3. Structure

    The temporalis muscle has a distinctive fan-shaped morphology:

    • Muscle type: Skeletal muscle (voluntary).

    • Fiber orientation: Posterior fibers run more horizontally, while anterior fibers run vertically, allowing for different movement vectors.

    • Tendon: The tendon passes beneath the zygomatic arch and inserts on the mandible.

    • Innervation: Deep temporal branches of the mandibular nerve (CN V3), a branch of the trigeminal nerve.

    • Blood supply: Deep temporal arteries, branches of the maxillary artery.

    4. Function

    The temporalis muscle has two main actions:

    • Elevation of the mandible: Closes the jaw during biting and chewing.

    • Retraction of the mandible: Posterior fibers pull the mandible backward, especially after protrusion.

    These functions work in coordination with other muscles of mastication like the masseter and medial/lateral pterygoids.

    5. Physiological role(s)

    The temporalis supports important daily and survival functions:

    • Mastication: Enables effective chewing and crushing of food.

    • Speech and articulation: Assists in jaw stabilization required for verbal communication.

    • Postural support of the mandible: Maintains resting tone to prevent jaw from hanging open.

    • Sensory feedback: Via muscle spindles, it contributes to proprioception of jaw position and movement.

    6. Clinical Significance

    The temporalis is involved in several musculoskeletal and neurological conditions:

    • Temporomandibular joint (TMJ) dysfunction:

      • Overactivity or spasm of the temporalis can cause jaw pain, limited range of motion, or headaches.

      • May present with tenderness at the temples or pain radiating toward the ear.

    • Tension-type headaches:

      • Temporalis muscle tension is a common contributor to stress-induced headaches.

    • Bruxism (teeth grinding):

      • Involuntary clenching or grinding of teeth can cause hypertrophy and soreness of the temporalis.

      • Long-term bruxism may lead to dental wear, jaw fatigue, and muscle imbalance.

    • Temporal arteritis (giant cell arteritis):

      • Inflammation of the superficial temporal artery may mimic temporalis-related pain; can lead to serious complications like vision loss.

    • Myofascial pain syndrome:

      • Trigger points in the temporalis can refer pain to the forehead, teeth, and upper jaw.

    Did you know? The clavicle is the only bone in the body that connects the arm to the body trunk.