The terms get used interchangeably and they shouldn’t. A night guard, a sports mouth guard, and a TMJ splint all sit in your mouth — but they’re built for entirely different jobs. Wearing the wrong one can be useless or even harmful.
Here’s the breakdown from our TMJ team in Dansville.
Night guard (occlusal guard)
Job: protect your teeth from the forces of nighttime grinding and clenching.
Built like: a thin, hard or semi-hard custom-molded tray that fits over either your top or bottom teeth.
Best for:
- Patients who grind or clench at night (bruxism)
- Patients with worn-down teeth, chips, or cracks
- Patients whose partner reports they grind
- Patients waking with jaw soreness or headaches
Sports mouth guard
Job: absorb impact during sports to prevent broken teeth and protect lips, gums, and jaw from blunt force.
Built like: a thicker, softer rubber or polymer guard that covers the upper teeth and absorbs blows.
Best for:
- Football, hockey, lacrosse, basketball, soccer, wrestling
- Boxing and martial arts
- Skateboarding, biking, skating (where falls happen)
Even non-contact sports cause dental injuries. The American Dental Association recommends mouth guards for any sport with a meaningful risk of contact.
TMJ splint (orthotic appliance)
Job: reposition the lower jaw to relieve TMJ joint stress and muscle tension.
Built like: similar to a night guard but designed with specific bite adjustments to position the jaw therapeutically.
Best for:
- Diagnosed TMJ disorder with joint or muscle pain
- Severe clenching with significant symptoms
- Jaw clicking, locking, or limited movement
This is more sophisticated than a standard night guard and requires careful fitting and follow-up.
Custom vs. store-bought
Boil-and-bite (drugstore)
You soften the guard in hot water and bite into it to create an impression. Cheap ($15-$40), available everywhere, decent for short-term use.
Problems:
- Bulky — uncomfortable, can affect breathing during sleep
- Tend to fall out at night
- Don’t distribute bite force evenly — can actually concentrate force in unhelpful ways
- Often too soft (chewable), which encourages MORE clenching
- Don’t address jaw alignment for TMJ cases
Custom (dental office)
Made from impressions of your teeth. Cost: $300-$700 for a standard night guard, more for a TMJ splint.
Why they’re worth it:
- Thin and comfortable — patients actually wear them
- Stay in place all night
- Distribute bite force evenly across all teeth
- Made of harder material that doesn’t encourage chewing
- Can be designed for your specific needs (bite, jaw position)
- Last 5-10+ years with care (drugstore guards last months)
The math actually works in favor of custom
A drugstore guard at $30 lasting 6-12 months = $30-$60/year. A custom guard at $500 lasting 7-10 years = $50-$71/year. Add the difference in comfort, fit, and effectiveness — and the math is clear, especially when chronic grinding is doing damage.
Insurance and night guards
Many dental insurance plans cover at least part of a night guard, especially when grinding has been documented or there’s evidence of wear. We’ll verify benefits and tell you what’s covered.
How to know which one you need
- Grinding/clenching at night with no jaw pain: standard night guard
- Sports: custom-fit sports mouth guard
- Jaw pain, clicking, headaches, severe clenching: TMJ evaluation first; possibly a TMJ splint
- Both grinding and TMJ symptoms: the splint addresses both
To get fitted for a night guard or evaluated for TMJ, call A Smile By Design at (585) 335-2120.