What is the hyoid bone?
The between the larynx and lower jaw lying hyoid bone is only about two to three inches long and bent u-shaped. It is usually considered part of the skull skeleton. This point is disputed, however, since the hyoid bone is already at the transition to the throat in the throat area.
The hyoid bone is an unpaired bone that can be felt through the skin as well as being displayed by conventional imaging techniques such as x-rays, ultrasound or computed tomography. The involvement of the hyoid bone in its environment is optimal, especially since it is fixed only with various muscles and ligaments in the skull base. A connection to other bones and thus to the skeleton does not exist. Skeletal models are therefore often incomplete with respect to the hyoid bone.
The complex interaction between the hyoid bone, the adjacent muscles and the surrounding body parts is the basis for a perfect swallowing, breathing and speaking. Even on the cough and various movements, the hyoid has an influence.
Anatomy & Construction
The hyoid bone is composed of a central part, the corpus ossis hyoidei, and four so-called hyoid horns. Two of the horns, medically Cornu majus, point to the back and end with a small thickening.
They form in the embryonic phase together with the middle of the cartilages of the third pharyngeal arch and are connected to the larynx. The two front horns, Cornu minus, are slightly smaller and come from the second pharyngeal arch. They are connected to the temporal bone via the styloid process - an ossified connection that can only be found in humans and other primates.
The muscles surrounding the hyoid bone are divided into two groups, each containing outer and deeper muscles. While the suprahyal musculature (geniohyoideus muscle, mylohyoideus muscle, digastric muscle, stylohyoid muscle) is able to pull up the hyoid bone, the infrahyal musculature (sternohyoid muscle, omohyoid muscle, thyrohyoid muscle) allows the tongue bone to descend. The muscles lead to tongue, throat and jaw. Even connections to the chest and shoulder blades are available.
Function & Tasks
Without the movement of the hyoid bone and the contractions of the muscles connected to it, the functions of speaking, breathing and also swallowing are not perfectly feasible. Only through the hyoid are, for example, the targeted movements of the tongue possible. This is stabilized by the small curved bone and only then allows the formulation of words.
The lingual bone is supported by the larynx, which is connected to it by a flexible membrane through which the upper laryngeal artery also leads. In addition to the larynx, the trachea is loosely attached to the hyoid bone. It can be closed or opened as needed. During the process of swallowing, the muscles pull the hyoid bone together with the larynx upwards and press the laryngeal lid against the inside of the neck and close the entrance of the larynx.
Other muscle groups in turn pull the hyoid bone down. The food is forced into the esophagus and respiration released by the trachea. Simultaneous swallowing and breathing is therefore not possible. However, when spoken in parallel, there is a risk that small food pieces touch the larynx and trachea and trigger a coughing sensation.
But not only when swallowing, the hyoid muscles play a major role. They serve, inter alia, by the connection to the floor of the mouth opening the jaw and the chewing movement. In addition, as part of the neck muscles, they participate in the coordination of movement of the shoulders and the neck area - a relationship that is often neglected.
Diseases of the hyoid bone are extremely rare. Only sporadically inflammation or tumors are observed in him. Occasionally carcinomas of the thyroid pass through the hyoid bone to the tongue. Cysts, however, usually form only in its environment and do not affect this bone.
The force of the tongue can also break through the action of force. For this, however, a large force is necessary, which can be achieved in strangling a person or in a strangulation. Since such a pressure is usually exerted involuntarily, the fracture of a hyoid bone is mainly in forensic medicine an issue. The force required for the fracture inevitably damages other parts of the neck and thus a fracture of the hyoid bone is almost without exception diagnosed in the dead.
In contrast, there are complaints such as breathing problems or poor posture of the body. They often occur, but in many cases are not immediately associated with the hyoid bone and adjacent muscles. An example of this is the lower jaw reserve, in which the hyoid bone is unusually loosely anchored and lies too far to the rear. The result is a narrowing of the trachea, which causes corresponding respiratory problems. An overstretching of the head, although a relief in respiration, but on the other hand can lead to tension, pain, migraine or miscarriage.
Also tension of the hyoid muscles can have far-reaching consequences. If your activity is restricted due to immobility, you may experience tense movements, a stiff neck or discomfort when swallowing.