1. A thrusting or forcing out of a normal position. 2. The overeruption or migration of a tooth beyond its normal occlusal position.
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ex·tru·sion ik-'strü-zhən n the act or process of extruding <\extrusion of proteins from cells>
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1. the forced eruption of a tooth by means of an orthodontic appliance; for example, to realign a tooth that has been accidentally forced into the jaw.
2. the partial lifting of a tooth from its socket as a result of traumatic injury.
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ex·tru·sion (ek-strooґzhən) 1. thrusting or pushing out; expulsion by force. 2. the overeruption or movement of a tooth beyond its normal occlusal plane in the absence of opposing occlusal force. 3. an orthodontic technique for the elongation or elevation of a tooth. Cf. intrusion.Medical dictionary. 2011.