The 'Millimeters of Bone' meme stems from the 'blackpill' and 'looksmaxxing' subcultures, where individuals obsess over minute physical measurements as the ultimate decider of social and romantic success. It specifically refers to the fatalistic idea that lacking just a few millimeters of bone in the jaw, chin, or brow ridge can ruin one's life prospects. While it started in niche forums, the phrase and accompanying diagrams of skull measurements eventually went viral on TikTok and Twitter. Today, it is mostly used ironically to satirize the extreme vanity and pseudo-scientific nature of those who over-analyze facial features to an absurd degree.