Can Clear Aligners Fix an Underbite? Everything You Need to Know

An underbite can affect more than your appearance — it can influence the way you chew, speak, and even how your jaw feels at rest. If you've been searching for information about underbite correction, you're not alone. Many adults in the UK are exploring whether clear aligners offer a realistic alternative to traditional braces or surgery. In this guide, we explain what determines suitability, how treatment works, what the limitations are, and what questions to ask before starting.

This guide is written for adults (and parents of teenagers) considering orthodontic treatment for an underbite. Whether you've had a consultation or are just beginning your research, the aim is to give you balanced, evidence-informed information — not a sales pitch. Every case is different, and an in-person orthodontic assessment is always required before treatment can begin.

Bite Basics: What Is an Underbite?

An underbite (known clinically as a Class III malocclusion) occurs when the lower front teeth sit in front of the upper front teeth when you close your mouth. In a normal bite, the upper arch slightly overlaps the lower arch. With an underbite, this relationship is reversed.

Underbites can vary significantly in severity:

• Mild dental underbite: the lower teeth are slightly ahead of the upper teeth, usually caused by tooth position rather than jaw discrepancy
• Moderate underbite: a combination of tooth misalignment and some jaw involvement
• Severe skeletal underbite: the lower jaw itself has grown significantly further forward than the upper jaw, or the upper jaw is underdeveloped

It's worth noting that an underbite is different from a crossbite, although the two can occur together. A crossbite refers to individual teeth or sections of teeth that sit inside or outside the opposing arch, whereas an underbite specifically describes the front-to-back relationship of the jaws.

What Causes an Underbite?

Common causes include:

• Genetics: jaw size and shape are largely inherited
• Childhood habits: prolonged thumb-sucking or dummy use can influence jaw development
• Tooth loss or crowding: missing teeth or crowding can cause compensatory shifting
• Jaw growth patterns: the upper and lower jaws may grow at different rates during adolescence

Can Aligners Help? What Determines Suitability

Whether clear aligners can fix an underbite depends on what's causing it and how severe the misalignment is. Here's what clinicians typically assess:

Cases Where Aligners Are Often Suitable

• The underbite is primarily dental — meaning it's caused by the position of the teeth, not the jaws themselves
• The degree of reverse overjet (how far the lower teeth are ahead) is mild to moderate
• The patient has good general oral health (healthy gums, no active decay)
• The patient is committed to wearing aligners for 20–22 hours per day

How Clear Aligners Correct an Underbite

Modern aligner systems use several tools in combination to achieve bite correction with aligners:

• Sequential tooth movement: each set of aligner trays makes small, planned adjustments — typically 0.25mm per stage
• Attachments: small tooth-coloured composite bumps bonded to specific teeth give the aligner something to grip, enabling more complex movements like rotation and root control
• Elastics (rubber bands): Class II or Class III elastics may be used alongside aligners to help reposition the bite. These hook onto small buttons or precision cuts on the aligners and apply gentle force to shift the jaw relationship
• IPR (interproximal reduction): in some cases, very small amounts of enamel are carefully removed between teeth to create space for movement

The use of attachments and elastics is particularly important for underbite correction. Without them, aligners alone may lack the force needed to achieve meaningful bite changes.

Typical Timelines

Treatment duration for underbite correction with aligners varies considerably. As a rough guide:

• Mild cases: approximately 6–9 months
• Moderate cases: approximately 12–18 months
• Complex cases (with elastics and refinements): 18–24 months or longer

These are estimates only. Actual timelines depend on compliance (how consistently you wear the aligners), the number of refinement stages needed, and whether any preparatory work (such as treating gum disease) is required before starting. Your clinician will give you a more specific estimate based on your 3D scan and treatment plan.

When Alternative or Combined Approaches Are Used

Clear aligners are not suitable for every underbite. In some situations, a different approach — or a combination of treatments — may be more appropriate:

• Fixed braces: may be recommended for severe dental underbites where more precise bracket-and-wire control is needed, particularly for significant root movements
• Orthognathic (jaw) surgery: for skeletal underbites where the jaws themselves are significantly misaligned, surgical repositioning may be the only way to achieve a stable correction. This is typically carried out in a hospital setting by a maxillofacial surgeon, often combined with pre- and post-surgical orthodontics
• Combined approach: some patients begin treatment with aligners to address the dental component and are then referred for further treatment if a skeletal issue becomes apparent during the process
• Growth modification (younger patients): in children and adolescents whose jaws are still developing, functional appliances or headgear may be used to guide jaw growth before any aligner treatment is considered

A responsible provider will always explain the full range of options during your initial assessment — including referral to a specialist if your case falls outside the scope of aligner treatment.

Risks of Leaving an Underbite Untreated

Not every underbite requires treatment. Very mild cases with no symptoms may be monitored rather than actively corrected. However, untreated underbites can lead to a range of functional and dental problems over time:

• Uneven tooth wear: when teeth don't meet correctly, certain surfaces experience excessive wear, which can lead to sensitivity, chipping, and the need for restorative work
• Chewing and eating difficulties: an underbite can make it harder to bite into food properly, which may affect nutrition and digestion
• Speech issues: some underbites affect the position of the tongue and lips, contributing to lisps or difficulty with certain sounds
• Jaw pain and TMJ problems: the jaw muscles and temporomandibular joint (TMJ) may be strained by a misaligned bite, leading to headaches, clicking, and discomfort
• Gum recession: teeth that are under abnormal pressure may experience gum recession over time
• Self-consciousness: an underbite can affect facial profile and confidence, though this is very personal and varies between individuals

If you're unsure whether your underbite needs treatment, an orthodontic assessment can help clarify your options without any obligation to proceed.

Who Clear Aligners May Not Be Suitable For

It's important to be transparent about the limitations of aligner treatment. Clear aligners may not be the right choice if:

• Your underbite is primarily skeletal (caused by the position or size of the jaw bones rather than just the teeth)
• You have active gum disease or significant tooth decay that needs to be treated first
• You have significant crowding or missing teeth that complicate the treatment plan
• You are unable or unwilling to wear aligners for 20–22 hours per day consistently
• You have certain medical conditions that affect bone density or healing
• You are a child or young teenager whose jaws are still actively growing — in these cases, interceptive orthodontics or functional appliances may be more appropriate

A good provider will be upfront if aligners aren't the right fit for your case. At Pro Aligners, if we assess that clear aligners aren't likely to achieve a stable result, we'll explain why and help you explore alternative options — including referral to an orthodontic specialist if needed. You can explore the range of aligner options we offer to understand the differences between our treatment tiers.

Safety and Compliance Notes for UK Patients

If you're considering aligner treatment in the UK, it's worth being aware of several important points:

General Dental Council (GDC) Guidance

The GDC has issued specific guidance on clear aligners, particularly regarding aligners sent directly to your home without an in-person clinical assessment. The GDC emphasises that orthodontic treatment should involve:

• A face-to-face clinical examination before treatment begins
• A full assessment of oral health, including X-rays where appropriate
• Ongoing monitoring by a registered dental professional
• Clear information about risks, alternatives, and what to do if something goes wrong

Advertising Standards

Under ASA/CAP rules, dental providers must not make misleading claims about treatment outcomes. This means you should be cautious of any provider that:

• Guarantees specific results
• Shows before-and-after images without appropriate context
• Advertises unrealistically low prices without disclosing what's included (and what's not)
• Uses urgency-based marketing ("limited time offer", "book today or miss out")

What to Ask Your Provider

Before committing to any treatment, consider asking:

• What is included in the quoted price? (Scans, aligners, refinements, retainers?)
• What happens if my treatment takes longer than expected?
• What are the realistic risks and limitations for my specific case?
• Who will be monitoring my progress, and how often?
• What happens if I'm not happy with the result?
• Is the treating clinician GDC-registered and experienced in aligner orthodontics?

Transparent providers will welcome these questions. You can view our pricing and what's included to see how we approach this at Pro Aligners.

Frequently Asked Questions

Can clear aligners fix a severe underbite?

In most cases, severe underbites — particularly those caused by skeletal jaw discrepancies — require fixed braces, jaw surgery, or a combined approach. Clear aligners are generally most effective for mild to moderate dental underbites. A thorough orthodontic assessment will determine which approach is appropriate for your case.

How long does it take to fix an underbite with aligners?

Treatment duration depends on the severity of the underbite and how consistently the aligners are worn. Mild cases may take 6–9 months, while moderate cases typically require 12–18 months. Complex cases involving elastics and refinement stages may take longer. These are estimates, and your clinician will provide a more specific timeline based on your treatment plan.

Do I need elastics (rubber bands) with my aligners for an underbite?

Many underbite cases treated with aligners do require elastics. Class III elastics are commonly used to help shift the bite relationship by applying gentle, sustained force. Your clinician will explain whether elastics are needed and how to use them correctly. Compliance with elastic wear is important for achieving the planned result.

Are clear aligners cheaper than braces for fixing an underbite?

The cost of aligner treatment varies depending on the complexity of the case and the aligner system used. In some instances, aligners and braces are similarly priced; in others, one may be more cost-effective. It's important to compare what's included in each quote — for example, whether refinements, retainers, and follow-up appointments are covered. See our pricing page for an overview of costs at Pro Aligners.

What happens if I don't treat my underbite?

Not every underbite requires treatment. Very mild cases with no symptoms may be monitored. However, untreated underbites can lead to uneven tooth wear, jaw pain, difficulty chewing, speech issues, and gum problems over time. If you're unsure, an assessment can help you understand your options.

Can an underbite come back after aligner treatment?

All orthodontic results — whether achieved with aligners or braces — require retention to remain stable. Without consistent retainer wear, teeth can shift back towards their original position. The British Orthodontic Society recommends long-term retainer use to maintain results. Your clinician will advise on the best retention plan for your case.

Is an underbite the same as a crossbite?

No. An underbite refers to the lower front teeth sitting ahead of the upper front teeth. A crossbite can affect individual teeth or sections of teeth on either side of the mouth, where they sit inside or outside the opposing arch. The two conditions can co-exist, but they are assessed and treated differently.

Can I fix an underbite with mail-order aligners?

The GDC strongly advises caution with mail-order or direct-to-consumer aligner services, particularly for bite correction cases. Underbite treatment often requires attachments, elastics, and ongoing clinical monitoring — none of which are typically available through remote-only services. An in-person assessment and regular face-to-face check-ups are recommended for safe, effective treatment.

What's the difference between a dental underbite and a skeletal underbite?

A dental underbite is caused by the position of the teeth — the lower teeth have drifted forward or the upper teeth have drifted backward. A skeletal underbite is caused by the size or position of the jaw bones themselves. Clear aligners can address dental underbites effectively, but skeletal underbites usually require jaw surgery or a combined surgical-orthodontic approach.

Disclaimer: This article is for general information only and does not constitute dental or medical advice. Every case is different, and treatment suitability can only be determined through an in-person clinical assessment by a GDC-registered dental professional. Timelines and outcomes described are estimates and may vary.