Invisalign for an underbite: what aligners can fix, what needs an orthodontist, and what it costs

Invisalign can fix a mild underbite when the cause is the position of the teeth, not the jaws: aligners tip the upper front teeth forward and the lower front teeth back. A skeletal underbite needs an orthodontist. At Toothi in Edgware, underbite cases are usually Invisalign Go at £2,495 or Go Plus at £2,995. In a dental or “pseudo” Class III underbite, a few lower front teeth are tipped forward, the upper front teeth are tipped back, or both. What aligners can’t do is move the jaws. If the lower jaw itself sits forward of the upper (a true skeletal underbite), the case may need orthodontics, sometimes with jaw surgery. We refer those cases on rather than attempting them with aligners.

You can’t always tell which it is by looking in the mirror. The iTero scan and X-rays at your free consultation show whether the teeth or the jaw are to blame, and we’ll tell you before anything is made. For how we treat Invisalign generally, see Invisalign in Edgware.

It matters because only a dental underbite is an aligner case. An underbite, or reverse overjet, means the lower front teeth sit in front of the upper front teeth when you bite together. Dentists call it a Class III bite, but the label covers two quite different situations.

• ✓  Dental (pseudo) Class III. The jaws are roughly the right size and place, but the teeth are tilted. Lower incisors lean forward, upper incisors lean back, or the lower jaw slides forward to get past an edge-to-edge contact. Often only two to four teeth are involved. This is the kind aligners can correct.
• ✓  Skeletal Class III. The lower jaw is genuinely longer or further forward than the upper, or the upper jaw is set back. The teeth may be upright; it’s the bone that’s out of balance. Aligners move teeth within bone and can’t change jaw position.
• ✓  Mixed cases. A mild skeletal tendency with the teeth compensating on top. The scan and X-rays decide the plan.

How we tell them apart: the iTero scan shows how far the lower teeth sit in front of the uppers and how tilted each tooth is, and a standard X-ray (included) shows root positions and bone levels. We also look at your profile and at whether you can bring your front teeth edge to edge. If you can, the underbite is more likely dental and treatable. If the chin is noticeably forward and the teeth can’t meet, it’s more likely skeletal.

By tipping the upper front teeth forward and the lower front teeth back until they pass each other and the uppers end up in front. To make room for the lowers to move back, we often plan a little interproximal reduction, which means polishing a fraction of a millimetre of enamel from between the teeth; see our IPR page. Small tooth-coloured attachments give the aligner something to grip. Occasionally, where the bite needs help settling, small elastics are worn between an upper and a lower aligner for part of the treatment.

Because the front teeth start the wrong way round, the plan is sequenced so they can pass each other without colliding. Usually the uppers move first and the lowers follow. The principles are explained in how Invisalign works, and a related bite problem is covered in Invisalign for a crossbite.

We treat dental underbites within the Invisalign Go range; skeletal and complex cases are referred on to an orthodontist. The Go range is designed for mild to moderate movement of the front and premolar teeth. A dental underbite involving a few tipped incisors, with the back teeth already biting together properly, sits inside that scope. Our principal dentist, who has a special interest in Invisalign, plans every case on the iTero scan first.

What we don’t take on with aligners: a skeletal underbite, a case needing extractions, a bite where the back teeth are also reversed on both sides, or anything needing more movement than the Go Plus scope allows. Those cases are referred on to an orthodontist. Some are treated with fixed braces or a comprehensive aligner system, and a minority of adult skeletal cases need orthodontics combined with jaw surgery. We’d rather tell you that at a free consultation than start a plan that can’t finish. See also Invisalign from a dentist or an orthodontist.

Typically around 6 to 9 months. A mild dental underbite is usually an Invisalign Go case, typically around 6 months, because the front teeth in both arches move and the bite has to settle at the end. Where more tipping is needed, or there’s heavier crowding as well, it becomes a Go Plus case, typically around 9 months. Go Express is rarely right for an underbite, because correcting a reversed bite almost always involves both arches. These are typical ranges, not promises. Your own duration is shown on the ClinCheck plan and depends on how far the teeth move and on 22-hour-a-day wear. See how long Invisalign takes; refinement aligners are included if needed.

Usually £2,495 (Go) or £2,995 (Go Plus), fixed and all-inclusive.

Included in every Invisalign package: iTero 3D scan and ClinCheck · all review appointments · refinement aligners if needed · removable and fixed retainers · Airflow hygiene clean · Boutique teeth whitening. There are no add-ons. Full detail on our fees page, in our Invisalign cost guide and on the packages page. 0% finance over up to 10 months is available on treatment over £250.

An examination, an iTero 3D scan, a predicted result on screen, and a straight answer on whether aligners can fix your bite.

• ✓  A proper examination first. A check-up and X-rays are part of every Invisalign assessment. Teeth and gums must be healthy before aligners start; any fillings or gum treatment are done beforehand and charged separately.
• ✓  The iTero 3D scan. A digital scan of both arches on our in-house iTero Lumina. No impression putty, and it takes a few minutes.
• ✓  A predicted result on screen. The scan simulates where the teeth could finish, so you see the corrected bite before any aligner is made. If the simulation can’t close the bite, you see that too.
• ✓  A clear answer. Dental, skeletal or borderline; Go, Go Plus, or referral. You leave with a fixed written price or a clear referral.
• ✓  Fitting is a separate visit. Typically 2 to 3 weeks after the plan is agreed, with reviews generally every 8 weeks. We’re open seven days; see travelling to Toothi.

With retainers, worn for life. A corrected underbite always wants to drift back, because your lower lip and tongue keep pushing where they always have. That’s why every Toothi package includes a fixed wire retainer behind the front teeth and clear removable retainers. You wear the removable ones as instructed at your fitting at first, then every night. Replacement retainers are £150 for one arch or £250 for both, and a replacement fixed wire is £250. Our retainers guide covers the routine.