What is an overbite?

What is an overbite?

Healthline says orthodontists use the word overbite for the lower teeth overlapping the upper teeth, with severity ranging from normal to severe depending on how far the upper teeth extend past the lower ones. The everyday name is buck teeth. Cleveland Clinic describes an overbite as a deep vertical bite, where the upper teeth overlap the lower teeth more than they should. The two pages describe the overlap in opposite words but mean the upper front teeth covering the lower. Some overlap is normal; the question is how much.

What is an overjet?

Healthline says an overjet is similar but the upper teeth stick out at an angle instead of overlapping vertically. In everyday talk the two are often mixed up, so ask your orthodontist which you have, because the treatment plan can differ. See our guide on how to fix an overbite.

What is an underbite?

Cleveland Clinic says an underbite is when the lower front teeth extend past the upper front teeth. The AAO says it is a bite problem in which the lower teeth or jaw sit in front of the upper teeth, reversing the normal arrangement, and estimates it affects 5 to 10% of people worldwide. It says underbites can be dental, meaning tooth position, skeletal, meaning jaw structure, or both.

What causes an overbite or underbite?

Healthline lists genetics such as jaw shape, crowded teeth or missing lower teeth, and childhood habits during jaw growth, including thumb sucking, pacifier use, long-term bottle use, tongue thrusting, nail biting, chewing on objects and mouth breathing. Cleveland Clinic's general causes of malocclusion include genetics, crowded or oversized teeth, jaw misalignment, thumb sucking or pacifier use, teeth grinding, tooth loss, TMJ disorders and jaw or mouth tumors. The AAO lists inherited jaw shape, uneven jaw growth, and childhood habits for underbites. Cleveland Clinic does not give causes specific to overbite.

Can an overbite cause problems?

Cleveland Clinic says untreated malocclusion can lead to gum recession, gum injury, jaw pain, malnutrition from chewing difficulty, sleep apnea or other sleep disorders and tooth erosion, and can contribute to tooth decay and gum disease. These are general complications of a misaligned bite, not all of which apply to every overbite. Healthline does not list specific symptoms, but says a severe overbite may require surgery.

How is an overbite treated?

Healthline lists traditional braces as the standard for severe cases, usually worn one to three years followed by a retainer; clear aligners for minor to moderate cases if worn consistently; headgear in growing children and teens to guide jaw development; and jaw surgery for cases too severe for braces alone, with braces before and after. Cleveland Clinic adds restorative dentistry and extractions to create room, and says treatment for underbite typically takes about two years on average. Our guide on whether Invisalign fixes overbite goes into more detail.

Underbite treatment

The AAO says the best approach depends on age, remaining jaw growth and severity. Braces suit underbites caused mainly by tooth position, sometimes with elastics to guide the jaw; clear aligners suit mild, mostly dental cases; a palatal expander with reverse-pull headgear helps growing children; and jaw surgery is for severe skeletal cases in adults, usually after growth ends and combined with orthodontics. It says mild underbites caught early can often be treated without surgery and recommends an early evaluation by age 7.

Can you fix it at home?

Healthline says stopping habits like thumb sucking may help children, but warns against internet products claiming to fix overbites, and says incorrect at-home pressure on the teeth and jaw can cause serious injury. Only a dentist or orthodontist should treat a severe overbite.

Questions to ask your orthodontist

Take these to your first appointment.

• Do I have an overbite, an overjet, an underbite, or a mix?
• Is the cause in my teeth, my jaw, or both?
• Which treatment do you recommend, and how long will it take?
• Could surgery be needed, and when would you know?
• How long will I wear a retainer afterwards?

Frequently asked questions