occlusion

1. 1. The process of occluding.
   2. Something that occludes.
2. Medicine. An obstruction or a closure of a passageway or vessel.
3. Dentistry. The alignment of the teeth of the upper and lower jaws when brought together.
4. Meteorology.
   1. The process of occluding air masses.
   2. An occluded front.
5. Linguistics. Closure at some point in the vocal tract that blocks the flow of air in the production of an oral or nasal stop.

[From Latin occlūsus, past participle of occlūdere, to occlude. See occlude.]

1. The trapping of small pockets of liquid in a crystal during crystallization. 2. The absorption of a gas by a solid such that atoms or molecules of the gas occupy interstitial positions in the solid lattice. Palladium, for example, can occlude hydrogen.

1. the act of closure or state of being closed. n 2. any contact between the incising or masticating surfaces of the upper and lower teeth.

A stage which may occur in a mid-latitude depression where the cold front to the rear catches up with the leading warm front, lifts the wedge of warm air off the ground, and meets the cold air ahead of the warm front. If this overtaking air is colder than the cold air which is ahead of it, it will undercut it, forming a cold occlusion. If, on the other hand, it is warmer than the cold air which is ahead of it, it will ride over it forming a warm occlusion. After its formation, the still-deepening low pressure centre moves polewards and westwards. The centre of circulation is now cold—the cold core. Precipitation may persist for several days.

Occlusion

Closure or obstruction of a hollow body structure.

1. the act of closure or state of being closed; an obstruction or a closing off.
2. the relation of the teeth of both jaws when in functional contact during activity of the mandible.

• abnormal o. — malocclusion.
• coronary o. — see coronary occlusion.
• functional o. — contact of the maxillary and mandibular teeth that provides the highest efficiency in the centric position and during all exclusive movements of the jaw that are essential to mastication without producing trauma.
• inflow o. — a technique used in cardiac surgery to produce complete circulatory arrest by temporarily interrupting venous return.
• traumatic o. — any abnormality of occlusion which causes injury to structures within the mouth.

1. The closing over of a tree wound by formation of callus.
2. The plugging of the xylem by fungi such as verticillium, causing the plant to wilt.

Look up occlusion in Wiktionary, the free dictionary.

Occlusion is a term indicating that the state of something, which is normally open, is now totally closed.

• In cardiology, the term is often used to refer to blood vessels, arteries or veins which have become totally blocked to any blood flow. For issues of artery occlusion, see stenosis, atheroma, and coronary catheterization.

• In ophthalmology or orthoptics, occlusion refers to the patching of a person's good eye, in order for their weaker eye to receive more visual stimuli - as in amblyopia.

• In audiology, occlusion refers to the phenomenon that when persons with normal hearing close off the opening into the ear canal, the loudness of low pitched sounds (presented by bone conduction) increases.

• In dentistry, occlusion refers to the manner in which the teeth from upper and lower arches come together when the mouth is closed.

• In psychology, specifically memory research, occlusion is the phenomenon of items associated to the same cue as the target blocking the successful retrieval of that target, through strength dependent response competition. The tip-of-the-tongue phenomenon is an example of occlusion.

• In meteorology, the term refers to the complex frontal structure formed when a cold front overtakes a warm front. It is associated with widespread, steady rainfall in advance of the occluded front. In addition to extratropical cyclones on the synoptic scale, occlusions also occur on the mesoscale, as when a rear flank downdraft occludes in a supercell thunderstorm.

• In computer graphics, the term is used to describe the manner in which an object closer to the viewport masks (or occludes) an object further away from the viewport. In the graphics pipeline, a form of occlusion culling is used to remove hidden surfaces before shading and rasterizing take place.

• In computer gaming audio engines, the term describes modification of the qualities of a sound that passes through or around an object so that the player experiences a greater sense of realism. For example, a sound that comes from behind a door realistically sounds as if it passed through a door.

• In physics, it means an enclosure of cool air around warm air that rises in the atmosphere

See also

• Ambient occlusion
• Occlusive dressing
• Occlusive
• Occultation

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