Pronunciation: /ˌæbɒˈkluːʒ(ə)n/ · Part of speech: noun · Field: dentistry / orthodontics

Definition. Abocclusion is a condition in which the teeth of the upper and lower jaws do not touch each other when the mouth is closed — that is, the opposing teeth fail to make contact. It is a type of malocclusion, the general term for any abnormal relationship or alignment between the upper and lower teeth.

How it works. Normally, when the jaws close, the upper and lower teeth meet in a regular, interlocking pattern that allows efficient biting and chewing. In abocclusion, this contact is absent: the teeth that should oppose one another remain apart, so the bite does not close properly. The lack of contact may involve some or all of the opposing teeth.

Context within dentistry. Abocclusion sits within the broader category of occlusion and malocclusion:

• Occlusion is the normal contact between the upper and lower teeth when the jaws are brought together.
• Malocclusion is any deviation from this normal contact — including crowding, overbite, underbite, crossbite, and open bite.
• Abocclusion specifically describes a situation where opposing teeth do not meet at all.

Clinical relevance. When teeth do not make proper contact, biting and chewing can become inefficient, and the forces of mastication may be distributed unevenly. Depending on the cause and extent, this can affect eating, speech, and the long-term health of the teeth and jaw joints. Assessment of how the teeth meet is a routine part of dental and orthodontic examination, and conditions affecting contact between the jaws may be managed with orthodontic or other dental treatment, depending on the individual case.

Distinction from related terms. Open bite describes a gap between the upper and lower front (or back) teeth when the jaws are otherwise closed, so the relevant teeth do not meet. Malocclusion is the umbrella term for any abnormal bite relationship. Occlusion refers to the contact itself. Abocclusion emphasises the absence of contact between opposing teeth.

Etymology. From Latin ab- meaning “away from,” combined with occlusion, from occludere, “to close up” (ob- = against + claudere = to close) — literally, a closing in which the teeth are held away from contact.

⚠️ Disclaimer: This explanation is provided for general educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional regarding any clinical questions or patient care decisions.