The '9 out of 10 Dentists' meme originates from the long-standing advertising trope where dental brands claim near-universal professional approval for their products. The humor centers on the mysterious '10th dentist'—the lone holdout whose refusal to agree suggests either a hidden truth or complete absurdity. On the internet, this concept evolved into a popular template used to represent contrarian opinions, weird outliers, or situations where one person's refusal to conform creates a hilarious contrast. It is frequently used to mock brand marketing or to call out that one friend who refuses to agree with a popular opinion.