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: Dental
Underdeveloped maxilla is seen in : 
Select and explain. 
A. Treacher Collins syndrome, B. Pierre Robin syndrome, C. Craniofacial dysostosis, D. Both 1 and 2
C: Craniofacial dysostosis
Answer: C: Craniofacial dysostosis 
Explanation: None