--- title: "Overjet vs Overbite UK | What's the Difference? (2026)" url: https://virtualconsultant.online/guides/overjet-vs-overbite-uk description: "Overjet and overbite explained — horizontal vs vertical front tooth overlap, what causes each, normal ranges, and how both are treated." updated: 2026-08-09T00:00:00Z publisher: Virtual Consultant Online --- Overjet Overbite Bite Problems # Overjet vs Overbite — What's the Difference? Overjet and overbite are two of the most commonly confused terms in orthodontics. One is a horizontal measurement; the other is vertical. They often occur together — but they require different treatment approaches. [Start Photo Assessment](https://virtualconsultant.online/evaluations/quote) [Compare Costs](https://virtualconsultant.online/costs) ## What is overjet? Overjet is the horizontal distance between the front edge of the upper front teeth and the front edge of the lower front teeth when the mouth is closed. A normal overjet is 2 to 4 mm. An increased overjet — where the upper front teeth protrude significantly ahead of the lower — is what is colloquially called buck teeth. It is associated with Class II Division 1 malocclusion and is measured in the horizontal plane: how far forward the upper teeth stick out relative to the lower. ## What is overbite? Overbite is the vertical overlap of the upper front teeth over the lower front teeth when biting. A normal overbite is 2 to 4 mm, where the upper teeth cover approximately one third of the lower front teeth. A deep overbite occurs when the upper teeth cover more than half of the lower front teeth. In severe cases, the lower incisors bite into the gum tissue behind the upper front teeth, which can cause damage to both teeth and gum. Overbite is measured vertically — how far down the upper front teeth overlap the lower. ## Can you have both? Yes, and it is common. Class II Division 1 malocclusion typically presents with both increased overjet and increased overbite. Thumb sucking and dummy use beyond age 3 to 4 can increase overjet while also deepening the overbite. An underdeveloped lower jaw tends to increase both measurements together. It is important to distinguish the two because the treatment mechanics required to address each are different even when both are present in the same patient. ## How overjet is treated Overjet correction requires retracting the upper front teeth, advancing the lower front teeth, or a combination of both. In growing patients, functional appliances such as twin blocks or Herbst appliances guide lower jaw growth forward, reducing overjet by influencing skeletal development. In non-growing adults with a skeletal component, jaw surgery may be required for the best functional and aesthetic result. Where the overjet is purely dental — teeth rather than jaws — fixed braces or clear aligners with or without extractions can correct the tooth position. ## How deep overbite is treated Deep overbite treatment involves intruding the upper or lower front teeth, extruding the back teeth to open the bite, or a combination. Bite turbos — small pads bonded to the upper front teeth or lower back teeth — disengage the bite and allow the teeth to move freely. Deep overbite is one of the more technically demanding movements to achieve with clear aligners; specialist planning with attachments is essential. Fixed braces can be more reliable for severe cases. Correcting a deep overbite is important not just aesthetically but to prevent ongoing trauma to the gum behind the upper front teeth. ## Useful related pages [Malocclusion UK](https://virtualconsultant.online/guides/malocclusion-uk) [Overbite and Underbite Treatment](https://virtualconsultant.online/guides/overbite-underbite-treatment-uk) [Bite Turbos Explained](https://virtualconsultant.online/guides/bite-turbos-uk) [Invisalign vs Braces](https://virtualconsultant.online/guides/invisalign-vs-braces-uk) [Children's Orthodontics UK](https://virtualconsultant.online/guides/childrens-orthodontics-uk) This guide is for general information only. It is not a diagnosis, treatment plan, or substitute for advice from a registered dentist or orthodontist. ### Compare next steps [Orthodontist Near Me](https://virtualconsultant.online/locations/orthodontic-treatment-near-me) [Clear Aligners Near Me](https://virtualconsultant.online/treatments/clear-aligners-near-me) [Invisalign Near Me](https://virtualconsultant.online/locations/invisalign-provider-near-me) [Browse Locations](https://virtualconsultant.online/locations) ### Ready for a clearer starting point? Upload guided photos and receive an indication of likely treatment options and pricing before booking appointments. [Get an Online Quote](https://virtualconsultant.online/evaluations/quote) ### Frequently Asked Questions What is a normal overjet? A normal overjet is 2 to 4 mm. An overjet of 4 to 5 mm is considered mildly increased. An overjet of 6 mm or more is typically classified as IOTN grade 4 or 5 and qualifies for NHS orthodontic treatment in eligible under-18s. What is a normal overbite? A normal overbite is 2 to 4 mm, with the upper front teeth covering approximately one third of the lower front teeth. A deep overbite is generally defined as more than 4 to 5 mm vertical overlap, or where the lower teeth are partially or completely obscured when biting. Are buck teeth the same as a large overjet? Buck teeth is the everyday term for what orthodontists call an increased overjet — upper front teeth that sit noticeably forward of the lower ones. Overjet is measured horizontally, in millimetres, from the tip of the upper incisor to the front surface of the lower incisor. A normal overjet is 2 to 4 mm; 6 mm or more is typically classified as IOTN grade 4 or 5 and qualifies for NHS treatment in eligible under-18s. The distinction that matters clinically is whether the protrusion comes from the teeth tipping forward or from the jaws themselves sitting in a Class II relationship, as that determines the treatment. Can clear aligners fix a deep overbite? Yes, but deep overbite is one of the more demanding movements for aligner systems. Success depends on specialist planning, the use of attachments, and appropriate tray change intervals. Fixed braces may be more reliable for severe cases. An experienced orthodontist will advise which system is best suited to your specific bite. What causes a large overjet in children? The most common causes are genetics, prolonged thumb sucking, dummy use beyond age 3 to 4, and mouth breathing. All of these can encourage the upper arch to narrow and the lower jaw to sit further back relative to the upper, increasing the overjet. Early intervention from around age 9 to 10 in growing patients can take advantage of jaw growth to reduce overjet without surgery. Can you have increased overjet and overbite together? Yes, and this combination is common, particularly in Class II Division 1 malocclusion where the upper front teeth both protrude forward and overlap the lower teeth more deeply than normal. An underdeveloped lower jaw tends to increase both measurements at the same time, as does prolonged thumb sucking or dummy use beyond early childhood. Even when both are present together, an orthodontist plans the correction for overjet and overbite separately, since the tooth movements needed to reduce each measurement are different. Explore your options Quick links Not sure where to start? Use these quick links to explore orthodontic treatments, typical costs, and helpful guides that explain what different options involve. Whether you're researching braces or clear aligners, comparing pricing, or just getting a feel for what comes next, you can browse at your own pace and come back when you're ready to request a quote. Explore [Get Quote](https://virtualconsultant.online/evaluations/quote) [Costs](https://virtualconsultant.online/costs) [Browse Treatments](https://virtualconsultant.online/treatments) [Teeth Straightening](https://virtualconsultant.online/treatments/teeth-straightening) [Browse Problems](https://virtualconsultant.online/problems) [Locations](https://virtualconsultant.online/locations) [Near Me](https://virtualconsultant.online/locations/orthodontic-treatment-near-me) [NHS Eligibility Checker](https://virtualconsultant.online/about/do-i-qualify-for-nhs-treatment) [IOTN Score Checker](https://virtualconsultant.online/about/iotn-score-checker) [How To Take Orthodontic Photos](https://virtualconsultant.online/about/process/how-to-take-orthodontic-photos) [Online Orthodontist](https://virtualconsultant.online/guides/online-orthodontist-uk) [Research Papers](https://virtualconsultant.online/research) [Social Channels](https://virtualconsultant.online/social) ## Ready for a personalised answer? Upload guided photos and get a tailored recommendation for your teeth and bite. [Start Photo Assessment](https://virtualconsultant.online/evaluations/quote) [Find an Orthodontist](https://virtualconsultant.online/locations) Citation details Title Overjet vs Overbite UK | What's the Difference? (2026) Publisher Virtual Consultant Online Published 2024-06-01 Updated 2026-08-09 URL [https://staging.virtualconsultant.online/guides/overjet-vs-overbite-uk](https://staging.virtualconsultant.online/guides/overjet-vs-overbite-uk)