Overbite

An overbite is the vertical overlap of the upper front teeth over the lower front teeth when you bite together. A small overbite is normal and part of a healthy bite. When the overlap is excessive, so that the upper teeth cover most or all of the lower front teeth, it is called a deep bite and is a type of malocclusion.

Why It Matters

A mild overbite rarely causes problems. A deep bite can make the lower front teeth bite into the gum behind the upper teeth, wear down the edges of the front teeth, and make restorations such as veneers or crowns on the front teeth more likely to chip. In some people it is linked to jaw-joint strain, although a deep bite does not always cause symptoms.

Clinical Details

• Overbite vs overjet: Overbite is the vertical overlap. Overjet is the horizontal distance the upper teeth sit in front of the lower teeth, often called "buck teeth" when it is large. The two are frequently confused and can occur together.
• Dental or skeletal: A dental overbite comes from the position of the teeth, for example over-erupted front teeth. A skeletal overbite comes from the size or position of the jaws, such as a smaller or set-back lower jaw.
• Common contributing factors: Inherited jaw shape, crowding, missing back teeth that let the bite collapse, worn back teeth, and childhood habits such as prolonged thumb-sucking.
• Assessment: The orthodontist measures the overlap and overjet, checks the molar relationship and takes photos, scans and X-rays to see whether the problem is dental, skeletal or both.
• Treatment with braces or aligners: Braces or clear aligners can open a deep bite by moving the front teeth and changing the height of the back teeth. Aligners may use small bite ramps to help.
• Growth modification: In growing children, functional appliances can guide jaw growth.
• Surgery: For a significant skeletal discrepancy in adults, orthodontics may be combined with jaw surgery.
• Retention: A retainer is needed after treatment to stop the bite from deepening again.

FAQ

How much overbite is normal?

A small overlap of a few millimetres, where the upper front teeth cover a small part of the lower front teeth, is considered normal. An orthodontist judges whether an overbite is excessive by measuring it alongside the rest of the bite.

Can Invisalign or clear aligners fix an overbite?

Many dental overbites can be corrected with clear aligners, often with attachments and bite ramps. Severe or skeletal cases may need fixed braces, an appliance or a combination with surgery.

Can veneers fix an overbite?

Veneers change the shape and colour of the teeth, not the position of the jaws, so they cannot correct the bite itself. In some cases they can improve how the front teeth look; see veneers for crooked teeth for when this is and is not suitable.

Can an overbite be fixed in adults?

Yes. Teeth can be moved at any age. Adults no longer have jaw growth to work with, so skeletal problems are more likely to need surgery in addition to orthodontics.