Reverse Curve of Spee: What It Means, Why It Happens, and How to Fix It
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If you've been told you have a "reverse Curve of Spee" — or you've come across the term while researching your bite, your TMJ, or why your orthodontic treatment left you with problems you didn't have before — you're asking the right question.
Because a reverse Curve of Spee isn't just a dental finding. It's a sign that the structural foundation of your jaw and skull is working in the wrong direction. And the conventional dental solutions for it — the ones you're most likely to be offered — have a track record of making things worse, not better.
Let me explain what's actually happening, and what the fix actually looks like.
A Quick Recap: What the Curve of Spee Should Look Like
In a healthy mouth, the biting surfaces of your lower teeth form an arc when viewed from the side. The front teeth sit lower, and as you move toward the back of the mouth, the back molars sit progressively higher. The result is a gentle upward curve from front to back.
This arc exists for a structural reason. The jaw evolved around it. The skull's soft tissue system — the fascia, connective tissue, and muscle that covers the 29 moveable bones of the skull — maintains its proper tension when this curve is present. The spine sits correctly beneath it. The whole system is, in a word, inflated.
When the Curve of Spee is healthy, everything downstream tends to be healthier too.
What a Reverse Curve of Spee Actually Is
A reverse Curve of Spee is exactly what it sounds like: the arc goes the wrong way.
Instead of the back molars sitting higher than the front teeth, the occlusal plane is either completely flat — no arc at all — or it curves in the opposite direction, with the back teeth sitting lower than the front. The arc that should climb toward the back instead dips down.
In some contexts, you'll also hear "reverse curve of Spee" used to describe a specific orthodontic wire used during braces treatment. This is a wire intentionally bent in the opposite direction of the natural curve — used to intrude (push down) the lower front teeth and extrude (pull up) the back molars to "level" the arch. The orthodontist is deliberately engineering a flat or reversed curve as a treatment goal.
That second use of the term is, in my view, one of the most destructive things happening in orthodontics today. And it happens routinely, in practices around the world, to kids and adults who have no idea what's being done to the structural foundation of their jaw.
How You End Up With One
There are a few routes to a reverse Curve of Spee:
Orthodontic treatment. This is the most common path in people who've had braces or aligners. "Leveling and aligning" is a fundamental orthodontic goal — the process of moving teeth to create a flatter, more even arch. A healthy Curve of Spee is often deliberately flattened or reversed in the process of creating what orthodontists consider a "correct" bite. The teeth look straight in photos. The arc that the skull depends on has been systematically dismantled.
Years of grinding. Grinding wears down the biting surfaces of the back teeth — the molars and premolars that sit highest in the natural curve. As those cusps wear flat, the arc that ran from front to back progressively disappears. The curve becomes flat, then eventually dips in the wrong direction as the front teeth maintain their height while the back teeth are ground lower.
Dental work that changed molar height. Crowns placed too low on back teeth, incorrect restorations, or the deliberate drilling down of molar contacts to "fix" an occlusion — any of these can eliminate the height of the back teeth and flatten or reverse the arc. This is exactly what happened to me in 2014, when a dentist in Vietnam drilled my back molars flat to "adjust my contacts." The consequences were severe and rapid.
Posterior open bite left unsupported. When a posterior open bite develops — where the back teeth no longer meet — and it's left without any structural support, the front teeth bear the full load of every bite. Over time, the back teeth can drift further from contact and the plane tips in the wrong direction.
What It Does to Your Body
Here's where the conversation moves past dentistry into something most dentists don't think about or talk about.
The Curve of Spee is a structural indicator. When it's healthy, the skull is properly inflated — the soft tissue covering the cranial bones is under the right kind of tension, the bones are properly spaced, and the system functions well. When the curve reverses, it's a sign that the soft tissue has deflated. The skull is collapsing inward. And everything downstream follows.
Think of the skull as a balloon covered in soft tissue. When the Curve of Spee is intact, the balloon is inflated — bones are spaced properly, the brain isn't being compressed, the spine hangs correctly underneath. When the curve is reversed or flat, the balloon has lost air. The soft tissue that was holding everything in proper tension has gone slack. The cranial bones begin to compress inward. The jaw drops into a lower, less supported position. The cervical spine compensates.
The downstream effects are not subtle:
Chronic tension in the neck, upper back, and shoulders. The spine is compensating for what's happening above it.
Brain fog and difficulty concentrating. A compressed skull is compressing what's inside it.
Facial asymmetry. As the balloon deflates unevenly, the face loses its structural definition and symmetry.
TMJ pain and dysfunction. The jaw joint is being asked to function in a position it was never designed to occupy.
Poor sleep. The structural tension in the neck and jaw interrupts the sleep architecture even in people who don't know they're grinding.
And over the long term — years and decades — the kind of accelerated structural aging that most people attribute to genetics or lifestyle but is actually the downstream consequence of losing this curve.
What the Conventional Dental World Does About It (And Why It Makes It Worse)
When conventional orthodontics identifies a reverse Curve of Spee — or a deep curve, or an open bite, or any deviation from their treatment template — the typical response is more mechanical intervention. A reverse curve wire to level things out. Elastics to change the vertical relationship. Potentially extractions to create space for repositioning. Sometimes surgery.
The problem with all of these approaches is the same: they use mechanical force to move teeth and bones without understanding what the soft tissue system needs.
The soft tissue that covers the skull doesn't care about the position you forced the teeth into. Once the mechanical force is removed — once the braces come off — the soft tissue pulls everything back toward where it was. This is why orthodontic relapse is universal. It's not that patients aren't compliant with their retainers. It's that the underlying system is trying to re-establish the structural equilibrium it had before. The retainer fights that equilibrium indefinitely, and the structural collapse continues in the background even while the teeth appear to stay straight.
Trying to fix a reverse Curve of Spee with more orthodontic force is like trying to inflate a balloon by squeezing it from the outside. You might temporarily change the shape, but the pressure makes everything worse.
The Actual Fix
The actual fix for a reverse Curve of Spee — or any flattened or reversed occlusal plane — works through the soft tissue, not against it.
The mechanism is this: by adding vertical height between the upper and lower teeth, without locking the jaw into a fixed position, you prevent the jaw from closing fully into its compressed position. This creates what I think of as a doorstop effect. The soft tissue covering the skull, which has been under insufficient tension, is placed under a gentle sustained stretch. Night after night, it responds. The skull begins to re-inflate. The cranial bones move back toward their correct positions. And as this happens, the Curve of Spee begins to restore itself — not because you forced it, but because the system is returning to its natural geometry.
I watched this happen on myself over years of tracking the process with what I call a tracking splint — a flat-surface lower splint where I'd bite on occlusal paper to map where my contacts were landing. As I improved, I was always grinding the front of the splint down — always developing more curve. The arc was returning. And the improvements in my skull, my spine, my cognition, and my face all tracked with it.
This is also why the same approach that rebuilds the Curve of Spee in someone who lost it through grinding will rebuild it in someone who had it deliberately flattened by orthodontics. The soft tissue physics are the same. The mechanism is the same. The results track the same curve.
How Long Does It Take?
This is the honest part of the answer: it takes time. Months of consistent nightly wear before you'll notice meaningful structural change. Years before the process completes.
But it compounds. The changes don't plateau after a few months and then stop — they continue building as long as you're consistent. And because the mechanism is working through the soft tissue rather than forcing mechanical movement, it's not fighting the body's equilibrium. It's working with it. Which is why the improvements tend to hold.
The alternative — more orthodontic treatment to address the reverse curve — might produce visible changes faster on a dental X-ray. But the structural picture underneath will continue to deteriorate, and the relapse is built into the treatment.
What to Do if You Have a Reverse Curve of Spee
Stop chasing mechanical fixes. If an orthodontist is recommending a reverse curve wire, additional braces, or any intervention that mechanically forces the curve in a direction, understand that this approach has a poor long-term track record and is likely to make the structural situation worse even if the dental aesthetics improve temporarily.
Start with the simplest structural support: a flat, hard mouthguard worn every night. Not a soft molded guard that locks your compressed bite in place — a flat, hard, unlocked surface that adds vertical height and allows the jaw to move freely. This is what creates the soft tissue stretch. This is what allows the curve to begin restoring itself.
The RevivOne is designed around exactly these principles: flat surface, hard material, no bite registration. It's the lowest-cost, most accessible way to start working with the mechanics of the Curve of Spee rather than against them.
Get the RevivOne at getreviv.com
RevivOne is an occlusal guard designed to help reduce bruxism (teeth grinding) and jaw tension during sleep. Individual results vary. The observations and community patterns described in this article reflect the founder's personal experience and reports from community members, and are not intended as medical advice.