Search results
Results from the WOW.Com Content Network
In response, the masseter muscles will jerk the mandible upwards. Normally this reflex is absent or very slight. However, in individuals with upper motor neuron lesions the jaw jerk reflex can be quite pronounced. The jaw jerk reflex can be classified as a dynamic stretch reflex.
Signs and symptoms of temporomandibular joint disorder vary in their presentation. The symptoms will usually involve more than one of the various components of the masticatory system, muscles, nerves, tendons, ligaments, bones, connective tissue, or the teeth. [23] The three classically described, cardinal signs and symptoms of TMD are: [11] [24]
In anatomy, the masseter [help 1] is one of the muscles of mastication. Found only in mammals, it is particularly powerful in herbivores to facilitate chewing of plant matter. [5] The most obvious muscle of mastication is the masseter muscle, since it is the most superficial and one of the strongest.
Trismus is defined as painful restriction in opening the mouth due to a muscle spasm, [5] however it can also refer to limited mouth opening of any cause. [6] Another definition of trismus is simply a limitation of movement. [4]
Activation of trigger points may be caused by a number of factors, including acute or chronic muscle overload, activation by other trigger points (key/satellite, primary/secondary), disease, psychological distress (via muscle hypertonia), systemic inflammation, homeostatic imbalances, direct trauma to the region, collision trauma (such as a car crash which stresses many muscles and causes ...
The parotid duct, a long excretory duct, emerges from the front of each gland, superficial to the masseter muscle. The duct pierces the buccinator muscle, then opens into the mouth on the inner surface of the cheek, usually opposite the maxillary second molar. The parotid papilla is a small elevation of tissue that marks the opening of the ...
The four classical muscles of mastication elevate the mandible (closing the jaw) and move it forward/backward and laterally, facilitating biting and chewing. Other muscles are responsible for opening the jaw, namely the geniohyoid , mylohyoid , and digastric muscles (the lateral pterygoid may play a role).
The jaw elevator muscles develop the main forces used in mastication. The force generated during routine mastication of food such as carrots or meat is about 70 to 150 newtons (16 to 34 lbf ). The maximum masticatory force in some people may reach up to 500 to 700 newtons (110 to 160 lbf ).