title: An orthodontic challenge.
mesh_terms: D002648:Child; D004200:Diseases in Twins; D005260:Female; D006801:Humans; D008310:Malocclusion / Q000601:surgery / Q000628:therapy*; D008445:Maxillofacial Development; D009967:Orthodontic Appliances; D011247:Pregnancy; D014081:Tooth Extraction; D014430:Twins, Monozygotic