What the 3D Scan Shows Before Invisalign Treatment

What the scan itself involves

A small wand is passed over your teeth and gums and builds a three-dimensional model on screen as it goes. There is no tray, no impression material, nothing to gag on. It takes a few minutes per arch, you can stop whenever you want, and you see the model appear as it is captured.

We take photographs at the same time, and X-rays where they are needed. The scan captures the surfaces of your teeth; the X-rays show what is under the gum. Neither is complete without the other.

What I am looking at

The first thing is how your teeth meet. Not how they look from the front, but how the upper and lower arches come together at the back, where the contact actually happens. A bite that looks fine in a photograph is often doing something quite different at the molars.

Then the amount of space available. Crowding is a mismatch between the size of your teeth and the size of your jaw, and the scan lets me measure that mismatch precisely rather than estimate it. That number decides a great deal: whether crowding can be resolved by expanding the arch, by creating small amounts of space between teeth, or whether an extraction has to be discussed.

The X-rays add what the scan cannot see. Root position and length, bone levels around each tooth, unerupted or impacted teeth, and the relationship between your upper and lower jaws as skeletal structures rather than as rows of teeth. This is where cases sometimes turn out to be more involved than the front view suggested.

The simulation, and what it is

The scan feeds a piece of planning software that shows your teeth moving from where they are now to where the plan puts them. You will see a before and after, and usually the intermediate stages.

It is a genuinely useful tool. It makes the plan visible, it shows you what is being proposed rather than leaving you to imagine it, and it lets us discuss alternatives concretely. I use it in every case.

And what it is not

The simulation is a plan, not a result. The software moves teeth as instructed. Your biology decides how closely they follow.

Some movements are highly predictable and the outcome will look very much like the preview. Others, particularly rotations of round-rooted teeth and any movement that requires a root to travel through bone rather than tip, are less reliable. Aligners in particular are better at tipping teeth than at moving them bodily, and the software does not distinguish between the two when it renders the picture.

This is why refinements exist. A set of additional trays partway through is not a sign that something went wrong; it is the plan being corrected against what actually happened. I would rather tell you now that refinements are common than have you feel misled at month fourteen.

The other limit worth stating plainly: the simulation shows teeth. It does not model your lips, your smile line, or how the result will look on your face. Those matter, and we discuss them separately.

What the scan changes about the plan

Occasionally the scan confirms exactly what I expected and we proceed. More often it adjusts something. A case that looked like straightforward crowding turns out to have a crossbite at the back that has to be addressed first. Roots sit closer together than the crown positions suggested, which limits how far a tooth can be moved. Bone levels indicate previous gum disease that needs stabilising before any force is applied.

These are not obstacles so much as information. They are the reason I will not quote you a timeline or a treatment type before the records exist. Anyone who does is working from the same photograph you are.

What you leave with

A clear statement of what your case actually needs, the simulation showing the proposed result, the realistic options with the trade-offs of each, an estimated timeline, and a written cost. If more than one approach would give you a stable result, I will say so and let you decide. If only one will, I will tell you that instead.

The scan belongs to your record. If you want to think about it, take the plan away and come back, nothing is lost.