What does underbite mean?
An underbite is a condition in which the lower jaw projects forward beyond the upper jaw. The term can refer either to the visible shape of the jaw or to the underlying dental relationship, making it useful in both medical and everyday descriptions. An underbite is quite different from a crossbite: the former describes the relative forward position of the jaws, whereas a crossbite describes upper and lower teeth meeting on the wrong sides. The word is most common in orthodontic discussion but also appears in descriptions of portraits, animal anatomy, and inherited facial features. Although some speakers may associate an underbite with a strong or unusual jaw, the term is generally neutral and should not be treated as inherently unflattering. For readers interested in anatomy or dentistry, it provides a precise term for a feature that is otherwise often described informally as the lower jaw coming forward.
nounA malocclusion or jaw structure in which the lower jaw projects forward beyond the upper jaw.
- A forward projection of the lower jaw beyond the upper jaw, or the dental condition characterized by such a projection.
"The portrait draws attention to the subject's pronounced underbite."
"Her slight underbite gives the portrait a distinctive expression."
"The orthodontist explained how the patient's underbite affected the way the teeth met."
The plural is used when referring to separate instances of the jaw condition or to multiple cases.
"Some patients have severe underbites that require orthodontic treatment."
In an underbite, the lower jaw gets there first.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does underbite come from?
Underbite is an English compound formed from under and bite. Both elements descend from Old English: under referred to a lower position or position beneath, while bite came from the Old English bītan, meaning to seize or pierce with the teeth. The dental sense developed by applying the directional idea of under to the relationship between the jaws.
How underbite is actually used
Underbite is primarily a descriptive noun. In dentistry and orthodontics it is a clinical term, while in general description it may sound observational or occasionally judgmental.
Easily confused with underbite
An underbite concerns the forward position of the lower jaw relative to the upper jaw, whereas a crossbite concerns upper and lower teeth meeting on the wrong sides of each other.