Frequently Asked Questions About Underbites

Orthodontists treat a variety of bite problems. One such problem is an underbite, also known in more scientific lingo as a Class III malocclusion or a prognathism. Underbites aren’t as common or well-known as their counterpart—overbites—but like any jaw and tooth alignment problem, they need to be taken seriously. Here’s some introductory information about underbites to help you gauge whether your child has one, and what can be done about it. If you know or suspect that your kid has an underbite, a consultation with an orthodontist is in order.

What Is an Underbite?

The defining characteristic of an underbite is when the lower front teeth fall in front of the upper front teeth when the mouth is closed. Typically, the upper front teeth should ever so slightly overlap the lower front teeth with proper jaw alignment. With underbites, the degree of lower tooth overlap can vary significantly from person to person

Is an Underbite Concerning?

Pronounced underbites are a cosmetic concern that can affect confidence and self-esteem, sometimes creating a somewhat bulldog-like appearance. But they’re not only a cosmetic issue. Underbites can also cause symptoms and lead to a number of complications. They may cause discomfort or pain, temporomandibular disorders, speech impediments or other challenges, difficulty biting and chewing food, difficulty properly brushing teeth, excessive wear on the teeth, gum damage, and even breathing trouble (especially during sleep).

What Causes an Underbite?

Often, the lower jaw is positioned too far forward in people with an underbite. But genetics is the most common underlying cause of this condition. People can inherit an underbite, and the size and positioning of their teeth are also determined by genetics. Genes can also cause imapactions, conditions like a cleft lip or palate, and other issues that may lead to various types of malocclusions. Childhood habits like thumb sucking, pushing against the teeth with the tongue, and prolonged pacifier or bottle use can also lead to an underbite, as can injuries to the jaw.

How Is an Underbite Treated?

Underbites almost always require treatment, and generally, the earlier the better. Braces, or sometimes even clear aligner alternatives, frequently suffice to correct underbites. Sometimes, devices that reposition or affect the growth of the jaws are used in children; these may include an upper jaw expander, a chin cap that restricts growth of the lower jaw, or a reverse-pull face mask that wraps around the head and pulls the upper jaw forward. Extreme cases and older children and adults may need surgical intervention, possibly including tooth extractions or a procedure to reposition the upper or lower jaw.