Completing orthodontic treatment only to feel the overbite persists is a common frustration. This often stems from a misunderstanding of what successful bite correction involves, coupled with the complex biological and mechanical challenges of moving teeth. While braces are highly effective at aligning teeth, the final result is influenced by factors ranging from underlying jaw structure to patient participation and the body’s natural tendency for teeth to shift back. This article explores why an overbite may seem to linger or return after the active phase of orthodontic care is complete.
Understanding Normal Bite Alignment
A small degree of vertical overlap between the upper and lower front teeth is characteristic of a functional, stable bite, known as occlusion. This natural overlap allows the teeth to shear food properly and protects the soft tissues of the mouth. The ideal vertical overlap, or overbite, is between 2 and 4 millimeters, meaning the upper teeth cover approximately one-third of the lower teeth. The term “overbite” is often mistakenly used to describe two distinct issues: a deep bite (excessive vertical overlap, covering the lower teeth by more than 4 millimeters) and an excessive overjet (horizontal protrusion, often called “buck teeth”). Your perception of an uncorrected overbite may simply be the normal, stable vertical overlap achieved by the orthodontist.
Factors Limiting Tooth Movement
An incomplete correction may occur if the problem was too severe for tooth movement alone. If the skeletal relationship between the upper and lower jaws is misaligned (a Class II malocclusion), braces may only offer a compromise. This is called dentoalveolar compensation, where teeth are moved to mask a jaw discrepancy. Tooth movement is a biological process relying on jawbone remodeling, and biological limitations can impede full correction. For instance, dense bone structure requires longer time for bone resorption and apposition, slowing progress.
Patient compliance with auxiliary appliances like elastic bands is a significant factor in overbite correction. Elastics apply the necessary inter-arch force to bring the upper and lower jaws into the correct relationship. If they are not worn consistently, the mechanical forces required to fully correct the bite are not delivered. Furthermore, excessive movement can lead to root shortening, which may force the orthodontist to stop treatment prematurely. If treatment stops before the full biological potential for tooth movement is reached, the overbite may not be fully resolved.
The Role of Retention and Relapse
In many cases, the overbite was successfully corrected during treatment but the teeth shifted back toward their original position, known as relapse. This is a natural tendency because the teeth and surrounding structures, including the periodontal ligament and gingival fibers, possess a “memory.” These fibers take a long time to reorganize into their new position, often requiring 12 months or longer to fully remodel. The most common cause of relapse is inconsistent use of the retainer, which holds the new alignment stable during this reorganization period. Failure to wear the removable retainer allows soft tissue forces from the lips, cheeks, and tongue to push the teeth back to an unstable position.
Continued facial growth in adolescents and young adults can also contribute to the perceived return of an overbite. If the lower jaw grows slightly less than the upper jaw after braces are removed, the skeletal discrepancy that caused the original overbite can re-emerge. This subtle change in jaw size compromises the stability of the final bite, leading to a gradual increase in the vertical or horizontal overlap over time.
When Orthognathic Surgery is Necessary
For some individuals, a persistent overbite is fundamentally a skeletal problem, rooted in the size or position of the upper and lower jaws. This severe jaw discrepancy, often classified as a Class II malocclusion, cannot be fully corrected by simply moving the teeth within the bone. When orthodontic limitations are exceeded, a stable result requires addressing the underlying skeletal imbalance.
Orthognathic surgery, or corrective jaw surgery, is the definitive solution for these severe skeletal discrepancies. The procedure involves surgically repositioning one or both jaws to achieve proper alignment with the rest of the facial structure. This provides a stable foundation for the teeth and improves the functional bite. Treatment requires a combined approach: orthodontics is performed both before and after the jaw surgery to align the teeth precisely over their respective jawbones.