Overbite — causes, risks and treatment

An overbite describes a vertical or horizontal overlap between the upper and lower front teeth. A horizontal overlap — where the upper teeth project forwards — is also known as an overjet. A vertical gap that prevents the front teeth meeting is called an open bite and can occur alongside an overbite.

Typically the upper teeth overlap the lower teeth by around 2–4 mm. An overlap of 4–6 mm is often described as a deep bite, and anything more than that as a severe overbite, where the lower teeth may be hidden almost entirely.

• Genetics and inherited jaw shape
• An under- or over-developed jaw
• Childhood habits such as prolonged thumb sucking, dummy use or tongue thrusting
• Nail biting or chewing on hard objects (pens, pencils)
• Crowded or missing teeth

• Skeletal — caused by the jawbones not developing in proportion to one another.
• Dental — caused by the way the teeth have erupted or moved (crowding, pressure from habits, missing teeth).

A small overbite usually doesn’t need treatment. A deeper overbite, left uncorrected, can contribute to:

• Accelerated wear of the front teeth
• Jaw, face and headache discomfort
• Speech difficulties
• Temporomandibular joint (TMJ) issues over the longer term
• Reduced confidence in the appearance of the smile

Whether treatment is right for you depends on a clinical assessment — including how the bite functions, not just how it looks.

Clear aligners. Mild and moderate overbites can often be improved with clear aligners — including our ProAligners system. Aligners are removable, near-invisible trays that move the teeth in small, planned steps. Suitability is confirmed after a 3D scan and clinical exam.

Fixed braces. Metal or ceramic braces (combined with a retainer afterwards) remain a reliable option, particularly for more complex movements. Treatment time typically ranges from one to three years depending on the case.

Jaw (orthognathic) surgery.Severe skeletal overbites — where the cause is bone position rather than tooth position — may require surgery in addition to orthodontics. Jaw surgery is not performed at London Braces; if it’s clinically indicated we’d refer you to an appropriate hospital-based maxillofacial team and can co-ordinate the orthodontic work needed before and after.

Once an overbite is corrected, retainers are used to hold the teeth in their new position. Without retainers, teeth tend to drift back over time. Outcomes vary between patients, and your clinician will explain what is realistic in your specific case at consultation.