The temporalis muscle is a key component of the human muscular system, particularly among the muscles of the head and face. It plays a significant role in essential daily activities.
Where to Find the Temporalis Muscle
The temporalis muscle is a broad, fan-shaped muscle located on each side of the skull, covering a significant portion of the temporal bone. It is easily felt on the side of the head, above the ear, particularly when clenching the jaw. This muscle originates from a wide area known as the temporal fossa, a shallow depression on the side of the skull, extending to the inferior temporal line of the parietal bone and the deep surface of the temporal fascia.
The muscle fibers converge downward, forming a strong tendon. This tendon passes underneath the zygomatic arch, the bony arch forming the cheekbone. It then inserts onto the coronoid process of the mandible, a projection on the lower jawbone, and extends to the ramus of the mandible. This connects the side of the skull directly to the lower jaw.
How the Temporalis Muscle Works
The temporalis muscle is one of the primary muscles involved in mastication, the medical term for chewing. Its fan-like structure, with fibers oriented in different directions, enables it to perform distinct actions on the lower jaw, or mandible. The anterior fibers of the muscle are oriented more vertically, and their contraction primarily works to elevate the mandible, effectively closing the mouth.
The posterior fibers run in a more horizontal direction. When these fibers contract, they retract the mandible, pulling the lower jaw backward. This combined action of elevation and retraction is important for biting and grinding food. The temporalis muscle also contributes to side-to-side grinding movements of the jaw.
The temporalis muscle receives nerve signals from the deep temporal nerves, branches of the mandibular division of the trigeminal nerve (Cranial Nerve V3). This innervation allows for the coordinated contractions necessary for chewing and other jaw movements. The coordinated action of the temporalis, along with other masticatory muscles, ensures the stability and function of the temporomandibular joint, which connects the jaw to the skull.
Maintaining Temporalis Muscle Health
The temporalis muscle, despite its strength, can be a source of discomfort and pain if its health is compromised. Issues such as tension headaches are often linked to tension or trigger points within this muscle, with pain sometimes felt in the temple area, jaw, or even radiating to the upper teeth. Overworking the temporalis muscle, through habits like frequent gum chewing or prolonged jaw clenching, can lead to muscle strain and the development of these painful points.
The temporalis muscle’s function is closely tied to the temporomandibular joint (TMJ), and dysfunction in this joint, known as temporomandibular disorder (TMD), often involves the temporalis. Symptoms of TMD can include jaw pain, clicking sounds, and difficulty opening or closing the mouth, with stress-induced teeth grinding (bruxism) being a common contributing factor. Poor posture, particularly a forward head posture, can also increase tension in the temporalis and jaw muscles, exacerbating discomfort.
To support the health of the temporalis muscle and alleviate related discomfort, several practices can be beneficial. Reducing overall stress through relaxation techniques like deep breathing and meditation can help minimize jaw clenching. Maintaining proper posture, especially when sitting for long periods, helps reduce strain on the jaw and neck muscles. Avoiding excessive jaw clenching, teeth grinding, and frequent chewing of hard foods or gum can also prevent overuse and allow the muscle to rest and recover.