The teeth of the lower jaw normally meet those of the upper jaw in what is called the occlusal plane. Deviations from this plane of contact are called nonocclusions and are malocclusions of the dentition. Causes include dental anomalies, facial skeletal anomalies, and dental trauma.
What is nonocclusion?
Occlusion is the term dentistry uses to describe any tooth contact between the lower and upper jaws. Nonocclusions refer to misalignments of the dentition. By occlusion, dentistry refers to any tooth contact between the lower and upper jaws. Accordingly, nonocclusion is understood by dentists as the lack of contact between the lower jaw teeth and the upper teeth. A healthy set of teeth has natural contact points when closed, which are also called the physiological occlusal plane or masticatory plane. This plane is sagittally and transversely curved and describes the ideal positional relationship between the lower jaw tooth row and the upper jaw tooth row. For a long time, the term occlusion was used exclusively to describe the final bite position. Thus, nonocclusion was understood as the lack of contact in the final bite position. These definitions are now outdated. Today, nonocclusion is rather understood as all malocclusions or deviations from the occlusal plane. Sometimes different types of occlusion are distinguished. In this context, static occlusion or nonocclusion describes, for example, tooth contacts or missing tooth contacts without mandibular movement. Other types of occlusion and nonocclusion are dynamic, centric, habitual, and traumatizing.
Function and task
In nonocclusion, there are insufficient points of contact between the rows of teeth of the maxilla and mandible. This phenomenon is also known as mandibular anomaly and can be caused by the misalignment of individual teeth, dental trauma, or misdirected dental treatment. All bite misalignments fall under the term nonocclusion. The most important malocclusions of the jaw include crossbite, open bite and forced bite. Physiological occlusion has many functions for humans. For example, when chewing, it enables ideal loading of the individual teeth and the temporomandibular joint. If, on the other hand, there is non-occlusion, the jaw is subjected to incorrect loads. As a result, permanent damage to the temporomandibular joint can occur. The masticatory musculature can also be permanently damaged due to nonocclusion. Sometimes additional symptoms such as headaches occur as a result of the malocclusion. Bite malocclusions are therefore usually treated by oral surgery so that natural occlusion is possible again. Bite malpositions with missing occlusion are either inherited or acquired. E.g., nonocclusive tooth positions can be formed by process due to grinding or other habits. Instead of the entire jaw, individual teeth are usually affected by the lack of contact. This is the case, for example, when a tooth of the upper jaw is too far inward or a tooth of the lower jaw row is too far outward. On individual teeth, nonocclusions can thus be caused, for example, by stubborn deciduous teeth that block a molar, for example, and are eventually pushed sideways by the permanent teeth. Nonocclusions differ in their severity and treatability. The occlusal plane is used by the dentist and the oral surgeon to objectify bite malocclusions. As a rule, a person’s jaw never corresponds one hundred percent to the idealized masticatory plane. Nonocclusion is therefore normal to a certain extent. However, due to today’s possibilities, dentists usually advise therapeutic measures for all nonocclusions.
Diseases and complaints
The cusps facing the cheek on the posterior teeth of the lower jaw are optimally centered between the cusps of the posterior teeth in the upper jaw. Thus, the incisal edges of the lower anterior teeth meet the surfaces of the upper anterior teeth facing the palate. In this way, the lower jaw fits like a foot into the slipper formed by the upper jaw. If this is not the case, there is an anomaly of the jaw, also known as crossbite. Causes of this phenomenon include, for example, progeny or disturbed muscle function.Nonocclusion in a crossbite can take various forms. For example, if the lower cusps meet the upper cusps of the teeth, this phenomenon is also called a head bite. If, on the other hand, the cusps of the lower posterior teeth facing the cheek bite past the cusps of the upper posterior teeth also facing the cheek, this is called a crossbite. A scissor bite is when a lower posterior tooth bites completely past an upper posterior tooth. This phenomenon is sometimes also referred to as buccal nonocclusion, i.e. nonocclusion facing the cheek. The incisors can also be affected by malocclusion. In this context, a frontal head bite is present when a lower incisal edge exactly meets an upper incisal edge. In a frontal crossbite of the incisors, on the other hand, those of the lower jaw are in front of those of the upper jaw. To be distinguished from this is the so-called deep bite, in which the teeth of the upper and lower rows overlap too far. This malocclusion can be seen particularly clearly on the front teeth and, if the posterior teeth are involved, can manifest itself in a short lower face with pronounced masticatory muscles. Open bite is the term used for all tooth malocclusions that deviate from the physiological occlusal plane. Malocclusions are either pure dental malocclusions or anomalies of the facial skeleton. Treatment depends on the severity of the malocclusion, the cause of the deviation, and the particular phenomenon present.
