Orthodontists specialize in correcting malocclusions, or misalignments of the teeth and jaws. The overbite, sometimes called a deep bite, is one of the most common issues they treat. An overbite is a significant vertical overlap of the upper front teeth over the lower front teeth. While a slight overlap is normal for proper biting function, an excessive overlap can lead to problems like abnormal tooth wear, jaw pain, and difficulty chewing. The approach an orthodontist takes to fix this condition depends on the underlying cause and the patient’s age.
Defining and Classifying Overbites
An overbite is defined as the vertical overlap of the upper teeth over the lower teeth, with a measurement exceeding the healthy range of approximately two to four millimeters. This condition is categorized as a Class II malocclusion, meaning the upper arch is positioned too far forward relative to the lower arch. The two main classifications—dental and skeletal—determine the necessary treatment path.
A dental overbite results from issues with the positioning of the teeth themselves, such as overcrowding or the over-eruption of the lower front teeth, while the underlying jaw structure is normally aligned. This type is simpler to correct because it only requires repositioning the teeth. Conversely, a skeletal overbite is caused by a misalignment of the jawbones, where the upper jaw may be positioned too far forward or the lower jaw is underdeveloped. Correcting a skeletal discrepancy often requires more complex methods to modify the bone structure rather than just moving the teeth.
Non-Surgical Correction Methods
For overbites primarily caused by tooth position, orthodontists rely on non-surgical methods designed to move the teeth into the correct vertical relationship. Traditional fixed braces utilize brackets bonded to the teeth and connected by archwires. These wires are periodically adjusted to exert continuous, gentle pressure. This system facilitates the intrusion (pushing up) of the upper front teeth and the extrusion (pulling down) of the lower front teeth to reduce the vertical overlap.
Clear aligners, such as Invisalign, offer a removable and less visible alternative, using a series of custom-made plastic trays to guide tooth movement. For overbite correction, aligners often incorporate specialized features like “bite ramps.” These are small, raised platforms behind the upper front teeth that engage the lower teeth when the patient bites down. This action helps push the molars apart and slightly intrude the incisors.
Both braces and aligners frequently use orthodontic elastics (rubber bands) to apply targeted, inter-arch force between the upper and lower teeth. These elastics are stretched between specific points on the upper and lower arches to help correct the bite relationship. The consistent force from the elastics works to modify the alignment of the dental arches, reducing the excessive overbite. These non-surgical techniques are most effective for mild to moderate cases and for addressing the dental component of a more complex malocclusion.
Addressing Skeletal Issues
When an overbite stems from a significant jaw misalignment, treatment must focus on modifying the underlying bone structure, especially in growing patients. In adolescents, functional appliances are used during growth spurts to harness the body’s natural development and guide the lower jaw forward. Devices like the Herbst or Twin Block appliance encourage the mandible to grow into a more forward position, correcting the skeletal discrepancy.
The Herbst appliance is a fixed device attached to the molars that uses telescoping rods to posture the lower jaw in a more advanced position. This constant forward positioning promotes favorable growth changes in the jaw joints and surrounding musculature. These appliances can achieve significant skeletal correction in a shorter time frame compared to using only braces.
For adults whose jaw growth is complete, severe skeletal overbites that cannot be camouflaged by tooth movement often require orthognathic surgery, or corrective jaw surgery. This procedure involves surgically repositioning the upper jaw, lower jaw, or both, to establish a functional and balanced bite. Orthodontic treatment is always performed before and after the surgery to align the teeth properly for the new jaw position.
Maintaining the Results (Retention)
Following the active phase of treatment, the use of a retainer is necessary to prevent the corrected teeth from shifting back toward their original positions, a process known as relapse. The bone and ligaments surrounding the teeth require time to stabilize in their new location after the forces from braces or aligners are removed.
Orthodontists typically prescribe one of two types of retainers.
Removable Retainers
Removable retainers include the Hawley retainer, which uses a metal wire embedded in an acrylic plate, or clear plastic retainers, such as the Essix type, which resemble clear aligner trays.
Fixed Retainers
Fixed retainers consist of a thin wire permanently bonded to the backside of the front teeth, usually on the lower arch, providing continuous, passive support. The first few months typically require full-time wear of a removable retainer, gradually transitioning to nightly wear to ensure the stability of the corrected overbite.