'Looksmaxxing' is an online subculture (largely young male) focused on maximising one's physical attractiveness through every available means — skincare, fitness, dental work, hairstyle, sometimes plastic surgery and extreme techniques. Some of it is healthy (good skincare, exercise); some is dangerous (bone-smashing, jaw-mewing) and tied to incel-adjacent communities that promote toxic ideas about looks determining worth. If your teen uses the term, calm conversation about what specific techniques they are interested in, and where the content is coming from, is worthwhile.