Mouth Deterioration
The inside of your mouth has decay, including your gums and/or lining. It causes halitosis (GM discretion on social interactions), and every twenty-eight days, the player must roll above the IE on 1d20 or lose a tooth (Roll 1d20 for location: 1−10 top row left-right, 11–20 bottom row left-right).
Real-world Examples
Gingivitis, Periodontitis, Malnutrition
Assistive Options
Normally, this is managed by hygiene and diet, but this awareness requires a technological level not normally available in a fantasy RPG world.