An overbite is a common dental misalignment where the upper front teeth significantly overlap the lower front teeth. While a slight overlap is typical for proper dental function, an excessive overbite, also known as a deep bite, can lead to various oral health concerns. Orthodontists classify an overbite as excessive if the upper teeth overlap the lower teeth by more than 2 to 4 millimeters. This condition involves a vertical misalignment, distinct from issues like overjet, where upper teeth protrude horizontally, or an underbite, where lower teeth extend beyond the upper teeth.
Understanding Overbite Variations
Overbites present in different forms, each with distinct characteristics. A vertical overbite, also known as a deep bite, occurs when the upper front teeth cover a substantial portion of the lower front teeth. This can range from a mild overlap to a severe deep overbite where the upper teeth completely conceal the lower teeth, sometimes causing the lower teeth to bite into the roof of the mouth. A horizontal overbite, often called an overjet, involves the upper front teeth protruding forward beyond the lower teeth, creating a noticeable gap. An overjet can often coexist with a vertical overbite.
Common Causes
Overbites often stem from a combination of factors, with genetics playing a substantial role. Inherited jaw size and shape can predispose individuals to misalignments.
Childhood habits also contribute to an overbite. Prolonged thumb-sucking or pacifier use, especially beyond age three or four, can exert pressure on developing teeth and jaws, leading to outward protrusion of the upper front teeth. Tongue thrusting, where the tongue pushes against the front teeth during swallowing, can similarly influence tooth positioning and jaw development. Disproportionate jaw development, such as a smaller lower jaw or an overly large upper jaw, can also result in an overbite.
Recognizing the Signs
An overbite can manifest through several indicators and oral health issues. The most apparent sign is when the upper front teeth significantly overlap the lower front teeth, sometimes obscuring the lower teeth. In severe cases, the lower teeth may even bite into the gum tissue behind the upper front teeth. Beyond aesthetics, an overbite can lead to functional concerns, including difficulty chewing certain foods due to improper bite alignment. Speech impediments, such as lisping, can also arise because misalignment affects tongue placement and airflow during speech.
An overbite can also cause discomfort and long-term dental problems. Individuals might experience jaw pain or discomfort, often linked to the temporomandibular joint (TMJ), due to strained jaw muscles and joints. Headaches and earaches can also be associated with this jaw strain. Excessive wear on tooth enamel is another concern, as improper contact can lead to accelerated erosion and sensitivity. An overbite can also make oral hygiene challenging, increasing the risk of plaque buildup, tooth decay, and gum disease.
Addressing an Overbite
Addressing an overbite begins with a thorough dental examination. Diagnosis often involves dental X-rays and digital scans to create models of the bite. An individualized treatment plan is then developed, often by an orthodontist.
Treatment options include various orthodontic appliances. Braces (metal or ceramic) gradually move teeth into correct positions. Clear aligners, like Invisalign, offer a discreet option for mild to moderate overbites.
Accessory appliances like elastic bands, palate expanders, or headgear may be used with braces to align jaws and guide tooth movement. For severe overbites, especially those from significant jawbone discrepancies, orthognathic (jaw) surgery may be necessary in addition to orthodontic treatment. After treatment, retainers maintain corrected tooth positions and prevent relapse.