Buck teeth — the colloquial name most patients grow up with — are clinically known as overjet. If you’ve noticed your upper front teeth protrude further forward than they should, or you’ve been told your bite is misaligned, this guide is for you. Overjet is one of the most common orthodontic conditions in adults — and today, most cases can be corrected without surgery.
What Is Overjet?
Overjet refers to the horizontal distance between your upper front teeth and your lower front teeth. In a healthy bite, there is a slight overjet of around 1–2mm — this is completely normal and expected.
When that horizontal gap exceeds 2mm, the upper front teeth begin to visibly protrude. The greater the overjet, the more pronounced the “buck teeth” appearance — and the more it can affect how you bite, chew, speak, and feel about your smile.
Overjet is not merely cosmetic. It is a functional bite issue that, if left untreated, tends to worsen over time.
Overjet vs Overbite: Understanding the Difference
These two terms are among the most commonly confused in orthodontics — and getting them right matters, because they require different treatment approaches.
Here is a clear comparison:
| OVERJET | OVERBITE |
| Horizontal protrusion | Vertical overlap |
| Upper teeth stick FORWARD | Upper teeth sit TOO DEEP over lower |
| “Buck teeth” appearance | “Deep bite” appearance |
| Caused by jaw length imbalance | Caused by jaw height imbalance |
| Both conditions frequently occur together — Class II malocclusion | → Smartee S8-SGTB corrects both simultaneously |
| For a deeper explanation of both conditions and a self-diagnosis guide, read our companion article: “Overjet vs Overbite: One Tiny Word, Very Different Problems.” |
What Causes Overjet (Buck Teeth)?
Overjet usually develops as a result of several factors working together — rarely a single cause in isolation. The most common contributors are:
- Jaw size, tooth size, and the relationship between upper and lower jaws are largely inherited. If a parent had overjet, children are at higher risk. Genetics
- Prolonged thumb-sucking, extended pacifier use, or chronic mouth breathing during key developmental years can push the upper teeth and jaw forward. Childhood habits
- A low or forward tongue resting position — particularly tongue thrusting — places constant pressure against the upper front teeth, gradually increasing overjet. Tongue posture
- When the upper jaw grows more than the lower jaw, or the lower jaw is underdeveloped (retrognathia), the upper teeth protrude relative to the lower teeth. Jaw growth discrepancies
- When lower front teeth are absent, the upper teeth have no opposing contact and can drift or erupt further forward. Missing lower teeth
Understanding the root cause matters clinically — because overjet driven by jaw position (skeletal overjet) requires a different treatment approach than overjet driven by tooth position alone (dental overjet). Dr. Gareth Ho’s 3D AI assessment identifies which type you have at your first visit.
Why You Shouldn’t Leave Overjet Untreated
Many people dismiss overjet as purely cosmetic and put off treatment for years. This is a mistake. Untreated overjet creates a cascade of functional and structural problems over time:
- Difficulty chewing and biting — protruding teeth alter how you break down food
- Speech difficulties — certain sounds (particularly ‘s’, ‘f’, and ‘v’) become harder to produce clearly
- Jaw pain and TMJ strain — misaligned bite places uneven stress on jaw joints and muscles
- Higher fracture risk — exposed upper front teeth are significantly more vulnerable to chipping and trauma
- Tooth wear — teeth meet incorrectly, causing accelerated enamel wear in the wrong places
- Gum recession and periodontal problems — misaligned teeth are harder to clean and place off-axis forces on the gums
- Progressive worsening — overjet does not self-correct; in most cases it increases with age
| KEY POINT Overjet will not fix itself. It is a structural bite issue that requires specialist orthodontic treatment to correct properly. The earlier it is addressed, the simpler and more stable the correction. |
How Is Overjet Treated Today?
Treatment depends on the severity of the overjet and whether it is primarily dental (tooth position), skeletal (jaw position), or a combination of both.
Here is the full treatment ladder:
| Severity | Treatment Option | ACAOO Approach |
| Mild | Clear aligners — shift teeth progressively and discreetly | Clear aligner therapy |
| Moderate | Traditional braces — reliable continuous tooth movement | Braces or aligner therapy |
| Moderate–Severe | Smartee S8-SGTB — jaw repositioning + teeth alignment together | S8-SGTB (preferred) |
| Extreme skeletal | Orthognathic surgery — reserved for cases aligners cannot correct | Surgical referral + orthodontics |
How ACAOO Treats Overjet: The Smartee S8-SGTB Advantage
For patients with moderate to severe overjet — particularly where jaw position (not just tooth position) is involved — The Australian Centre for AI Orthodontics and Orthopaedics offers the Smartee S8-SGTB: the most clinically advanced non-surgical option available for Class II malocclusion.
What Makes the Smartee S8-SGTB Different
Standard clear aligners are excellent at moving teeth. They are not designed to reposition the jaw. This is the critical limitation — because most moderate-to-severe overjet cases are caused by a jaw imbalance, not just tooth protrusion. Treating the teeth alone leaves the underlying cause uncorrected.
The Smartee S8-SGTB solves this. It combines:
- Clear aligner tooth movement — shifting teeth progressively into correct positions
- Mandibular repositioning technology — gently guiding the lower jaw forward into its optimal position
| WHAT THE SMARTEE S8-SGTB CORRECTS Deep overjet (horizontal protrusion) | Deep overbite (vertical overlap) | A deep Curve of Spee | Class II jaw relationship — all simultaneously, without surgery. |
The result: reduced tooth protrusion, corrected jaw position, improved bite function, enhanced facial profile — all achieved with a removable, discreet aligner system.
The S8-SGTB Treatment Journey at ACAOO
- AI-Powered 3D Assessment — We begin with advanced 3D intraoral scanning and AI analysis — mapping your overjet, jaw position, bite depth, and facial profile in precise detail. This determines whether your overjet is dental, skeletal, or both, and confirms whether the S8-SGTB is the right fit for your case.
- Personalised Treatment Plan — Dr. Gareth Ho designs a fully customised plan using the Smartee S8-SGTB aligner system. The plan maps out the staged jaw repositioning and simultaneous tooth movement required to achieve your specific correction.
- Staged Jaw and Teeth Correction — The S8-SGTB works in calibrated progressive stages. Each set of aligners simultaneously advances the lower jaw and aligns the teeth — addressing both the cause and the visible result of your overjet in parallel.
- Retention — Once your overjet is corrected, custom retainers are fitted to maintain the new jaw and tooth positions and prevent any relapse. Long-term stability is built into the treatment plan from the outset.
- Remote Monitoring via DentalMonitoring AI — Between visits, our team uses DentalMonitoring technology to track your progress remotely. This means fewer clinic appointments without sacrificing oversight — and immediate adjustments if anything needs attention.
Why Choose ACAOO for Overjet Treatment in Sydney?
ACAOO is a specialist orthodontic centre — not a general dental practice. That distinction matters significantly when treating a condition like overjet, where the root cause often involves jaw structure, not just tooth position.
Dr. Gareth Ho has been treating complex Class II cases in Sydney for over 20 years. In 2025, he launched AI Orthodontics Australia — integrating the latest AI-powered diagnostic and monitoring tools into every treatment plan. The result is faster assessments, more precise treatment planning, and smarter oversight throughout your correction.
For patients who want complete discretion during treatment, lingual braces — placed on the inner surfaces of the teeth, invisible from the outside — are also available as an alternative or complement to clear aligner therapy.
| ACAOO · SYDNEY CBD · WORLD SQUARE Ready to fix your overjet without surgery? Book a consultation with Dr. Gareth Ho at our Sydney CBD clinic. We will assess your overjet with 3D AI imaging and tell you honestly whether the Smartee S8-SGTB can correct your case — without surgery. BOOK YOUR CONSULTATION → |
Frequently Asked Questions
Can overjet fix itself?
No. Overjet does not self-correct. In most cases it gradually worsens with age as jaw growth, tooth wear, and soft tissue changes progress. Specialist orthodontic treatment is the only way to properly correct it.
How long does overjet treatment take?
It varies by severity and whether the issue is dental, skeletal, or both. Mild cases can see meaningful improvement in 6–12 months. Moderate to severe cases involving jaw repositioning with the Smartee S8-SGTB typically take 12–24 months. Dr. Gareth Ho will give you a specific timeline after your initial 3D assessment.
Can adults get overjet treatment?
Absolutely. Modern systems like the Smartee S8-SGTB are highly effective for adult patients with fully developed jaw structures. ACAOO has specialised in adult orthodontic treatment since 2007 — there is no ‘too late’ for overjet correction.
Can overjet be fixed without surgery?
Yes — in the majority of cases. While extreme skeletal misalignment occasionally requires orthognathic surgery, most overjet cases — including many that are moderate to severe — can be corrected non-surgically using the Smartee S8-SGTB. If you have been told surgery is your only option, we encourage a specialist second opinion consultation with Dr. Gareth Ho before proceeding.
Is the Smartee S8-SGTB the same as Invisalign?
No. Standard clear aligners like Invisalign move teeth only. The Smartee S8-SGTB is a specialised system that additionally repositions the lower jaw — making it far more effective for overjet cases where jaw position is the underlying cause. It is a clinical step up from conventional clear aligner therapy.
