Normally jaw is formed by the set of bones that hold teeth. Jaw consist of two parts. Upper part is called maxilla and lower part is called mandible. The changes in the positioning of jaw or misalignment of jaw is called jaw disorders.
There are several types of jaw disorders that include:
- Temporo mandibular joint disorder (TMJ disorder)
- Prognathism
- Malocclusion
- Bruxism
Temporomandibular Joint Disorder
Temporomandibular joint is the joint where mandible meets the skull. Misalignment of jaw is due to the dis-functioning of temperomandibular joint. There are three categories of TMJ disorders. It includes:
- Myofacial pain: Discomfort or pain in the muscle involves in the control jaw movement.
- Internal disarrangement of joint: It involves in the dislocation of jaw, injury to the condyle.
- Arthritis: Inflammation of joins that affects the temporomandibular joint.
Prognathism
Prognathism is the condition in which protrude of either of the jaws beyond a predetermined imaginary line in the coronal plane of the skull.
- Alveolar prognathism: Protrusion of the portion of the maxilla where teeth are located in the upper jaw. It is due to the habit of thumb sucking or oral thrushing.
- Maxillary prognathism: It is also called over bite. In this, upper jaw protruding beyond the lower jaw causes upper front teeth to overlap on lower front teeth.
- Mandibular prognathism: It is also called under bite. In this, lower jaw protruding beyond the upper jaw causes lower front teeth to overlap on upper front teeth.
Malocclusion
It is the misalignment of teeth between the two dental arches. Improper fitting of upper and lower teeth when biting and talking.
- Cross bite: Upper teeth fit into the wrong side of the lower teeth.
- Transposition: Eruption of tooth in another tooth position.
- Open bite: In this upper and lower teeth do not overlap and creates straight opening into the mouth. This can be treated by wearing braces, removal of teeth if over crowding of teeth takes place. If it cannot be treated by the above methods, it can be treated by undergoing surgery called orthognathic surgery.
Bruxism
Bruxism is the excessive clenching or grinding of teeth and jaw and leads to jaw pain. This is due to the non functional repetitive contact of upper and lower teeth.
There are two types of bruxism:
- Sleep bruxism is the clenching and grinding of teeth or jaw during sleep.
- Awake bruxism is the clenching of teeth while awake.
Bruxism can be treated by wearing mouth guards and night guards to prevent clenching and grinding of teeth and jaw during day or night time.
