Mouth injuries are common, especially in children, and may involve the teeth, jaw, lips, tongue, inner cheeks, gums, roof of the mouth, neck, or tonsils. A tooth can be knocked out (avulsed) during play or during a traumatic injury to the mouth. A baby tooth (primary tooth) is not put back in the socket (reimplanted) after it has been knocked out because the reimplantation may cause problems with later development of the permanent tooth.

If a primary tooth is knocked out before it is ready to come out, the premature loss of the tooth may delay the permanent tooth development. Your dentist may recommend putting a spacer in the empty socket until the permanent tooth comes in.

If a piece of the knocked-out tooth breaks off and is left in a cut, it can delay healing and cause infection. An X-ray may be needed to make sure a tooth fragment wasn't left in a cut.