Which night guard should I get? An estimated 8.6% of people grind or clench their teeth while sleeping. If you’re one of the many who suffer from bruxism, investing in a night guard may help prevent adverse effects, including chipped or cracked teeth, damaged fillings, jaw pain and headaches. There are plenty of night guard options available, but knowing what to look for and choosing the right one can be challenging. What to know before you buy a night guard How do night guards work? It might surprise you, but night guards’ design doesn’t prevent you from grinding your teeth or clenching your jaw.