title: Accidental swallowing of orthodontic expansion appliance keys: report of two cases.
mesh_terms: D002648:Child; D005260:Female; D005547:Foreign Bodies / Q000209:etiology* / Q000517:prevention & control; D006801:Humans; D009967:Orthodontic Appliances / Q000009:adverse effects*; D010155:Palatal Expansion Technique / Q000295:instrumentation*; D013270:Stomach