The quote humorously suggests that a foundational understanding of understatement is essential for future medical professionals, implying that doctors often must downplay or mask the truth for various reasons. By referring to it as a prerequisite for "Lying Through One's Teeth," it indicates that such communication skills are a part of their education, especially in sensitive situations.
In the context of Jodi Picoult's novel "Perfect Match," this interplay between honesty and understatement reflects on the moral dilemmas faced by individuals in the medical field. It highlights the complexity of truth-telling in medicine, where sometimes what is left unsaid can be just as significant as what is articulated.