title: Extraoral control of geometry for digital subtraction radiography.
mesh_terms: D002508:Cephalometry / Q000295:instrumentation; D006801:Humans; D008433:Mathematics; D010510:Periodontal Diseases / Q000000981:diagnostic imaging; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods*; D013382:Subtraction Technique; D014070:Tooth / Q000033:anatomy & histology / Q000000981:diagnostic imaging*