The dental occlusion refers to the contact between the teeth of the upper jaw, or maxillary teeth, and the teeth of the lower jaw, or mandibular teeth. Static dental occlusion refers to contact between the teeth when the jaw is at rest and dynamic occlusion occurs when the jaw moves, such as during chewing or chewing. Proper occlusion is important for dental health and general health.
When the cusps of the mandibular teeth fully interact with the cusps of the maxillary teeth, the occlusal position is called maximal intercuspation. The cusps of a tooth are the protruding parts at the top of the tooth, as opposed to the central groove at the top of the tooth. The natural position reached during maximum intercuspation is called centric occlusion, or habitual bite. This occlusion can also be called a convenience bite, or intercuspation position (ICP), and in simple terms, it means the natural position of the teeth when the teeth bite down fully. Dental occlusion depends on bone structure, muscles, nerves, tooth structure, and sometimes posture.
A proper habitual bite means no underbiting, overbiting, or crossing of teeth. In a young person with an ideal bite, all the teeth should make contact. If that patient shifts the jaw to one side, the eye tooth or lower canine should slide over the upper canine so that the back or posterior teeth no longer touch and the lower jaw drops slightly. This is called canine orientation. Anterior guidance in an ideal bite occurs when the person pushes their jaw forward and the lower front teeth slide up over the front teeth, so the back teeth do not touch.
An ideal bite should also have proper centric relation, the resting position of the temporomandibular joint (TMJ), or jaw joint. This means that the ball of the joint is in a central location in the socket. Individual tooth positions can vary from person to person.
A malocclusion occurs when the teeth and jaws are misaligned in the usual bite. Although most people have a slight degree of malocclusion and do not require treatment, this condition can cause health problems in the temporomandibular joint, teeth, jaw muscle, and gums. Malocclusions are commonly classified using the Angle classification method, created by Edward Angle, a prominent orthodontist of the late 19th and early 20th centuries. The classifications are based on the position of the maxillary first molar in relation to the rest of the occlusion.
Class I has normal molar occlusion, but other teeth may be crowded or erupted above or below their intended location. A common example of excessive eruption occurs when the canine tooth pushes through the gum labially, above the primary tooth. Class II is commonly known as an overbite, in which the upper teeth are placed too far forward. Class III includes patients with lower bites, in which the mandibular anterior teeth are positioned in front of the maxillary anterior teeth. Worn teeth, from overactive jaw muscles, grinding, and eventual lack of canine guidance, can also cause malocclusion. These conditions can be treated with dental braces, tooth extraction, and sometimes orthognathic or jaw surgery.