Do Night Guards Change the Curve of Spee? What They Actually Do

1) Quick definitions you can trust

The curve of Spee is the front-to-back arc of your lower teeth when viewed from the side.
A night guard (occlusal splint) is a removable appliance that spreads bite forces and reduces clenching damage.
One is shape of teeth.
The other is protective gear.
Different tools.
Different jobs.

2) Short answer vs long answer

Short answer: a guard won’t flatten a deep curve.
Long answer: a guard can change how your bite feels in the morning because muscles relax and the appliance adds temporary thickness.
Your teeth didn’t move overnight.
Your muscles and contacts did.

3) What night guards actually do

They distribute force so one tooth doesn’t take all the load.
They reduce muscle overactivity by giving a smooth, even surface.
They protect enamel from grinding and micro-fractures.
They raise vertical dimension slightly while worn, which can offload front teeth.
They deprogram habits so your true bite shows up at the dentist.

4) What night guards do not do

They do not intrude incisors or extrude molars.
They do not level a deep curve of Spee.
They do not cure TMJ on their own.
They support comfort while you address root mechanics.

5) Why your bite may feel “different” in the morning

Muscles are calmer, so your jaw closes along a truer path.
The guard’s thickness spreads contacts more evenly.
You might notice a temporary posterior open bite right after removal that fades as muscles “wake up.”
That’s sensation, not structural change.

6) The rare exception people point to

If a hard guard is worn 24/7 or is poorly adjusted for months, tiny tooth movements can happen.
That’s misuse, not the goal.
We wear guards at night, review fit, and avoid long-term daytime chewing on them.

7) Soft vs hard vs dual-laminate — my take

Hard acrylic splints are the most stable for heavy grinders.
Soft splints can be comfortable but may invite more chewing for some people.
Dual-laminate blends comfort and firmness.
Custom fit beats boil-and-bite for durability and balance.

8) Upper vs lower — which to choose

Both work if they’re designed and adjusted well.
I choose based on dental work, crowding, airway comfort, and patient preference.
Upper is common.
Lower can be easier for some jaw shapes.

9) Anterior deprogrammers and NTI devices

These touch front teeth only to relax the masseter/temporalis.
They are not long-term all-day appliances.
Use with supervision and periodic checks.
Great for muscle down-regulation.
Not for leveling a curve.

10) Night guards vs mandibular advancement devices (MADs)

A guard protects teeth and muscles.
A MAD moves the jaw forward for snoring or mild OSA.
Different indications.
If snoring is an issue, learn the difference here: How jaw alignment impacts sleep.

11) Want to actually change a deep curve of Spee

You’ll need orthodontics.
Braces with a reverse-curve archwire can intrude fronts and level the arc.
Aligners can program incisor intrusion with bite ramps to reduce front collisions.
Start here: Reverse Curve of Spee Archwires: A Patient’s Guide and Aligners and the Curve of Spee: Week-by-Week Changes.

12) The combo plan I use most

Guard now for protection and muscle calm.
Orthodontics later if mechanics still overload front teeth.
Retention and a light guard after treatment if you’re a lifelong clencher.

13) Four-week feel-timeline most patients report

Week 1: pressure tenderness fades, fewer morning zings.
Week 2: chewing feels less “pinchy” on the fronts.
Week 3: jaw wakes up looser, fewer afternoon tension spikes.
Week 4: sleep feels deeper if grinding was waking you.

14) How I check if the guard is actually helping

Morning jaw tension score 1–10.
Chewing comfort score 1–10.
Headache frequency log.
Right-profile smile photo monthly to watch curve trend (shape shouldn’t change from the guard).
Use this guide: How to Measure Your Curve of Spee at Home (Safely).

15) When a guard might make you worse

It’s too thick and strains your joints.
It has high spots so you rock on one tooth.
It’s a soft chewy that you chomp all night.
Fix = adjust, remake, or switch material with your dentist.

16) Kids and teens — different rules

Guards protect during sports or severe grinding phases.
They do not guide growth or level a curve.
If you see front-tooth wear or a deepening bite, evaluate for orthodontics early.
Read: Kids and Teens: When a Deep Curve of Spee Needs Action.

17) TMJ, headaches, and the honest claim

A guard can reduce muscle load and clench triggers.
Headaches tied to grinding often improve.
TMJ is multifactorial, so expect relief, not a magic cure.
For nuance, read: TMJ, Headaches, and the Curve of Spee: Evidence vs Hype.

18) Cleaning and lifespan

Rinse after each wear.
Brush with a soft brush and non-abrasive cleaner.
Avoid hot water.
Most custom guards last 2–5 years depending on bite force and care.

19) Red flags that need a call

Persistent new joint pain.
One tooth hurts sharply on removal.
Bite feels worse after two weeks of wear.
Snoring gets louder or you notice breathing pauses at night.

20) Buying and fitting — simple, safe, effective

If you’re going to buy, start here: The Best Mouthguard for TMJ Pain: A Buyer’s Guide.
For fitting basics, use: What Is a TMJ Mouthguard and How to Fit It Correctly.
For how guards work under the hood, read: How TMJ Mouth Guards Actually Work.

 

FAQs

Do night guards change the curve of Spee
No.
They protect and calm muscles.
They don’t move teeth.

Why does my bite feel open in the back after I take the guard out
Muscles relaxed and the appliance added temporary thickness.
It settles as you chew and talk.

Can a guard fix a deep bite
No.
It may reduce symptoms, but leveling needs orthodontics.

Could a guard make my bite worse
Yes if it’s poorly fitted, too thick, or chewed all night.
Get it adjusted or remade.

Are boil-and-bite guards okay
They’re fine short-term.
Custom lasts longer and balances forces better.

Upper or lower guard — which is better
Both work.
Choose based on your teeth, airway comfort, and preference.

Will a guard stop my snoring
Not usually.
Consider a mandibular advancement device if snoring or mild OSA is the main problem.

Can aligners replace a guard
During active movement, the aligner acts like a light appliance.
Post-treatment, a dedicated guard is better for heavy clenchers.

How long until I feel a difference
Often within one to two weeks.
Muscle relief usually comes before any bite feels “even.”

Do kids need guards for grinding
Only if they chip or wear teeth or play contact sports.
 Orthodontics handles curve and bite issues.

Bottom line + CTA

A night guard won’t change your curve of Spee, but it can change your day-to-day comfort while you decide whether to level the curve with orthodontics.
Protect your enamel now.
Fix mechanics if contacts stay uneven.
If you want a comfortable, protective option today, consider a Reviv mouthguard and start sleeping easier.
Encourage readers to buy Reviv Mouthguard or other Reviv products by clicking Here.