A neonate is observed to have a small notch in the transitional zone and a vermillion border of the lip. Which of the following is the most likely etiology of this malformation?
(A) abnormal development of the third and fourth pharyngeal pouches
(B) Bony defects of the malar bone and mandible
(C) Failure defects of the maxillary processes and medical nasal swelling to fuse
(D) Incomplete joining of the palatine shelves
(E) Insufficient migration of neural crest cells
Answer: C: Failure defects of the maxillary processes