Why do I keep biting my cheek?

The first bite is an accident; every bite after is geometry. Once you catch your cheek, the spot swells - and the swollen ridge sits a little further into the path of your molars, so tomorrow's meal bites it again. The cycle usually breaks once the area heals, which is why leaving it alone (slow meals, small bites, chewing on the other side for a few days) works. Recurring cheek biting beyond that pattern has real causes. Teeth that meet slightly off - a malocclusion, in dental terms, which MedlinePlus notes covers crowded or crooked teeth - can keep one cheek in the firing line, and erupting wisdom teeth push the back molars into new contact with the cheek. Some people also chew their cheek as a stress habit, the way others chew pens - the NHS lists feeling tired, stressed or anxious among mouth ulcer triggers, and cheek biting feeds straight into ulcers. The stakes are mostly comfort: the NHS names biting the inside of your cheek as a top cause of mouth ulcers, which take a week or two to heal and hurt the whole time. Break the loop: eat slowly without phone distraction, salt-water rinses for the sore spot, and a soft-bristled toothbrush. See a dentist if you bite the same spot over and over - smoothing one cusp or adjusting one filling can end it - and see a GP or dentist about any chewed spot that has not healed within 3 weeks. Pymander is a free AI doctor, 24/7 by text, that can help you judge the pattern.