"The Dentist" is another vignette that gives insight into the experience of being in the war and with a company of people not of one's own choosing. Curt Lemon seems to be the type of person who is constantly testing himself and gauging himself against some inner criteria he has about what it means for a person to be brave or what it takes to be a man. Each time he passes one of these inner tests he feels the need to brag about it, probably because he is the one most surprised by the exploit. The narrator's final conclusion is that, "Maybe it was a low opinion [of himself] that he kept trying to erase." In any case, when he fails the test of the dentist, he is embarrassed to the point where he needs to create an even more difficult situation than the one he failed. He wakes up the dentist and forces him to extract a healthy tooth just so Lemon could show he could endure the pain and the fear.
The first line of the story indicates that its purpose is to excuse the fact that the narrator does not really mourn Lemon's death and does not want become sentimental about him now that he is dead. To prevent this, this story is told. This story is placed immediately after "How to Tell a True War Story." So, is it true? If the answer matters, says the narrator, you have your answer. But maybe there is a better reason for this story's placement. In "How to Tell a True War Story" the narrator has just finished spoiling all of his plots and characters, telling the reader that none of what he has been telling the reader is real. So now he needs to draw you back again. By telling a story about Curt Lemon and why he was not a person to get sentimental about, the narrator once again establishes his character as a real person.