[Densitometry using the copper step wedge for X-ray opacity of the maxillary sinus].
D003300:Copper; D003720:Densitometry; D006801:Humans; D008443:Maxillary Sinus / Q000000981:diagnostic imaging*; D008961:Models, Structural; D011859:Radiography; D014962:X-Ray Film
D003300:Copper