This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Radiographic finding of floating teeth can be seen in - 
Select and explain. 
A. Ectodermal dysplasis, B. Cleido cranial dysplasia, C. Osteopetrosis, D. Histiocytosis - X
D: Histiocytosis - X
Answer: D: Histiocytosis - X 
Explanation: On radiographic examination of mandible, erosion of the bony alveoli around the teeth, so that they seem to be floating in space.
Seen in histiocytosis X.