dental arches

nomenclature

A scientific naming system

TMJ dysfunction

It is a condition (TMJ) that occurs when there's an abnormality within the joint. This condition can include degeneration of the articular disc, eminence, or condyle. More often its a result of a combination of several problems.The most severe TMJ problems must be treated surgically.

temporomandibular joint (TMJ)

is the movable hinge where the maxilla and mandible meet. The TMJ gets its name from the two bones that meet at this area, the temporal base and the mandible. The joint itself consists of three major bony parts: The articular eminence, glenoid fossa, Condyloid process.

articular eminence

is the raised section of the temporal bone that guides the mandible.

occlusion

There's a specific pattern formed as the jaw opens and closes, and the teeth touch together. This pattern is formed when the maxillary and mandibular arches meet. It is known as a person's "bite" or "bite pattern". It is made possible only by the ability the lower jaw to move.

rotational movement

It occurs when the lower jaw opens causes the condyle to rotate within the glenoid fossa. This occurs when the jaw opens to approximately two-thirds of its capacity. As the mandible continues to open, it enters the transitional movement, the condyle slides down the articular eminence on the articular disc. This process causes the jaw to move down and forward to create a wider opening.

quadrants

The maxillary and mandibular arches are further divided into quadrants (quarters), each defined by the right and left sides. These quadrants are formed by the midlilne, an imaginary line that vertically bisects the oral cavity into right and left sides. The midline starts between the central incisors of the mandible and maxilla and continues straight back toward the posterior of the oral cavity, ending at the oropharynx. Each quadrant contains 8 teeth.

dental arches

The maxillary arch (upper jaw) and the Mandibular arch (lower jaw)

meniscus

also known as the articular disc. aids the condyle in sliding along the articular eminence. It consists of tough connective tissue an fits into the glenoid fossa when the jaw is closed.

capsular ligament

is a dense, fibrous connective tissue that encloses the TMJ. It attaches to the neck of the condlye and the temporal bone. It functions to support and protect the joint from trauma.

glenoid fossa

is an oval depression of the temporal base that houses the condyloid process

mandibular arch (lower jaw)

is located on the lower portion of the oral cavity. It houses 16 permanent teeth in the same number and variety as the maxillary arch. The arch is mobile it opens and closes via a hinge-like joint called the temporomandibular joint.

Maxillary arch (upper jaw)

is located on the upper portion of the oral cavity. Because its attached to the main part of the skull, its stationary doesn't move when the mouth is opened. The arch houses 16 permanent teeth.

condyloid process

is the head of the mandible that fits into the glenoid fossa. The process articulates with the fossa in the temporal bones to form the temporomandibular joint.