A gomphosis is a joint that anchors a tooth to its socket. These joints have a very limited range of mobility to hold the teeth firmly in place, although as illustrated with braces, it is possible to move them incrementally over time. They line the upper and lower jaw in each tooth socket, and are also known as peg and socket joints. Each tooth has bony protrusions, the pegs, that latch into the socket with the assistance of the gomphosis. Disorders of the mouth sometimes involve these joints.
This particular joint is an example of a synarthrosis, a joint with limited to no movement. Several other joints of this type can be found in the body, including the connections between the plates of the skull. The gomphosis is made up of fibrous tissue, a collection of tough ligaments that attach to the socket and base of the tooth. As people grow up and lose their initial set of baby teeth, the new teeth develop gomphoses to anchor them in the jaw.
One disorder that can affect the gomphosis is scurvy, a disease of connective tissue. Connective tissues like the ligaments around the teeth, as well as the gums, can start to dissolve. Patients with untreated scurvy can develop loose teeth that may eventually fall out because the joints are too unstable. Periodontal infection and inflammation can also damage the joint, causing pain and erosion in the soft tissue. Other time, chronic dental problems may loosen the ligaments and lead to tooth loss or instability.
Patients with braces and retainers take advantage of the limited range of movement offered by the gomphosis to pull teeth into new positions. This may be necessary for a variety of reasons. The goal is to align the teeth evenly to create a strong, healthy bite. Braces are adjusted incrementally over time to pull and push the teeth into place. Between each adjustment, the teeth and jaw have time to recover.
Dentists may encounter the gomphosis in various procedures on the teeth, particularly extractions. In an extraction, the dentist works to remove a tooth in one piece, taking care to get the dental roots and everything else attached to the tooth. The presence of tough ligaments can make an extraction challenging, and the dentist must use appropriate levels of pressure to cautiously pull out the tooth without damaging the jaw. After an extraction, the dentist may need to treat the socket to limit the risk of infection and keep the patient comfortable.