This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Surgery
Dentigerous cyst arises from 
Select and explain. 
A. The root of a caries tooth, B. The periosteum of the fractured mandible, C. An unerupted permanent tooth, D. The sequenstrum of osteomyelitis of mandible
C: An unerupted permanent tooth
Answer: C: An unerupted permanent tooth 
Explanation: Dentigerous cyst is a unilocular cystic swelling arising in relation to the dental epithelium from an unerupted tooth SRB,5th edition,360.