med. : Articulatio temperomandibularis
Introduction
The joints provide the mobility of the human body. They connect one or more bones together. Depending on their tasks, we distinguish between: The temporomandibular joint (Articulatio temperomandibularis) is a rotating and sliding joint.
The joints have a complicated structure and place high demands on diagnostics and therapy.
- Ball joints
- Hinge joints
- Pan joints
- Sliding joints
- Swivel Joints
The socket of the temporomandibular joint is located close to the auditory canal and is firmly connected to the temporal bone. The counterpart is the head of the jaw, a bone process of the lower jaw.
The joint surfaces are covered with cartilage, as in the other joints. The entire joint is enclosed by a joint capsule. A viscous synovial fluid ensures better gliding.
Between the two joint surfaces there is a cartilage disc that divides the joint into an upper and a lower half. When moving the jaw, the joint can be felt well in front of the ear. The two temporomandibular joints connect the upper and lower jaws.
If the rows of teeth are aligned with each other when the mouth is closed, the joint heads should lie centrally in the socket. Any deviation from this position is registered by the joint and attempts to compensate. This leads to a one-sided load with temporomandibular joint pain.
The causes must be eliminated. The temporomandibular joints ensure the opening and closing of the oral cavity. Due to their rotational mobility, they enable the grinding of food.
They are also involved in speaking and swallowing. The anatomy of the jaw in the human body is such that optimal food intake is possible. The components are the upper and lower jaws, which are hardly comparable with each other, since they are structurally so differently constructed.
- The upper jaw bone has a loose, honeycomb structure while the lower jaw bone is much denser. Both jaws are used for fixing the rows of teeth. In the upper jaw, the roots of the teeth lie close to each other or even partially in the two maxillary sinuses.
The upper jaw is firmly attached to the bony palatal plate, the maxillary sinuses, the nasal bone and the zygomatic bone.
- In the lower jaw there is a canal containing blood vessels and nerves that innervates and supplies the entire lower jaw teeth with nutrients. The lower jaw is movable and connected to the skull via the temporomandibular joint, while the upper jaw is an integral part of the skull bone and cannot be moved.
The jaw muscles, or masticatory muscles, are a group of muscles that enable all movements and functions of the jaw and joint. The jaw muscles include four different muscles, all of which have different functions and are present once on each side of the jaw.
The only one of them, which is responsible for opening the mouth, is the lateral pterygoid muscle. When this muscle is tensed simultaneously on both sides, the jaw is moved forward, which initiates the mouth opening. The other three muscles are jointly responsible for closing the jaw. The musculus masseter, the musculus pterygoideus medialis, and the musculus temporalis. With the help of these muscles, the jaw can exert insane forces, and it is not uncommon for forces of over 100kg/cubic centimeters to be generated.