Structure and Development
- Arises from the temporal fossa and deep part of temporal fascia
- Passes medial to the zygomatic arch
- Inserts onto the coronoid process of the mandible
- Covered by the temporal fascia
- Accessible on the temples and can be seen and felt contracting
- Derived from the first pharyngeal arch in development
- Has a complex structure
- Sarcomeres are a consistent length
- Larger muscle fibers vary in length within the muscle and between individuals

Blood and Nerve Supply
- Receives blood supply from the deep temporal arteries
- Anastomoses with the middle temporal artery
- Controlled by the third branch of the trigeminal nerve
- Supplied by the deep temporal nerves
- At least 6 smaller branches recruit muscle fibers
- Recruitment of motor units maximizes contractile strength

Function
- Most powerful muscle of the temporomandibular joint
- Can be divided into anterior and posterior parts
- Anterior portion elevates the mandible (closing the mouth)
- Posterior portion retrudes the mandible
- Middle portion used for both elevation and retraction, as well as lateral movement of the mandible

Clinical Significance
- Involved in jaw pain and headaches
- Overwork of the temporalis muscle can result in pain
- Bruxism and jaw clenching can lead to temporalis muscle overuse
- Myotendinous rupture of the temporalis muscle can occur during a seizure
- Extreme clenching of the jaw during a seizure can cause the rupture
- Temporalis muscle may be used in reconstructive surgery of the mouth
- Incisions during pterional craniotomy are chosen based on ease of reattaching the temporalis muscle

Additional Information
- Temporal muscle (red)
- Muscles of head and neck
- Deep dissection of temporal muscle
- Mummification process
- References to relevant studies and publications