Albert Barnes Commentary Job 41:14

"Who can open the doors of his face? Round about his teeth is terror." — Job 41:14 (ASV)

Who can open the doors of his face? — His mouth. The same term is still used to denote the mouth—from its resemblance to a door. The idea is that no one would dare to force open his mouth. This agrees better with the crocodile than almost any other animal. It would not apply to the whale. The crocodile is armed with a more formidable set of teeth than almost any other animal; see the description in the notes at (Job 41:1).

Bochart says that it has sixty teeth, and those are much larger in proportion to the size of the body. Some of them, he says, stand out; some of them are serrated, or like a saw, fitting into each other when the mouth is closed; and some come together in the manner of a comb, so that the grasp of the animal is very tenacious and fearful; see a full description in Bochart.