A<unk>  <unk>  is any object originating outside the<unk>  of an organism. In machinery, it can mean any unwanted intruding object. Most references to<unk> es involve propulsion through natural orifices into hollow organs.<unk> es can be inert or irritating. If they irritate they will cause inflammation and scarring. They can bring infection into the<unk>  or acquire infectious agents and protect them from the<unk> 's immune defenses. They can obstruct passageways either by their size or by the scarring they cause. Some can be toxic or generate toxic chemicals from reactions with chemicals produced by the<unk> , as is the case with many examples of ingested metal objects. With sufficient force (as in firing of bullets), a<unk>  can become lodged into nearly any tissue.
Foreign body
Croup
Gingival cyst
Vaginitis
Laryngeal cyst
Odontogenic tumor
Dental abscess
Odontoma