Most patients complete underbite treatment in 18 to 30 months. Mild dental underbites can resolve in as little as 18 to 24 months. Moderate cases typically run 24 to 30 months. Complex skeletal cases in adults that require jaw surgery alongside braces take approximately two to three years in total.
Underbite correction takes longer than most orthodontic problems because it involves moving both arches simultaneously, not just straightening individual teeth. Severity, age, and how consistently elastics are worn all determine where on that range your case lands.
What follows covers what drives the timeline at each severity level, how treatment differs across age groups, and what to expect.
Dental vs Skeletal: Why the Distinction Matters
Before any timeline makes sense, it helps to understand what kind of underbite is being corrected.
A dental underbite happens when the teeth are angled incorrectly. Upper front teeth tip inward while lower front teeth tip outward, creating the appearance of an underbite even when the jaw bones sit in reasonable alignment. Dental underbites are more common and more straightforward to correct with braces alone.
A skeletal underbite involves the jaw bones themselves. The lower jaw has grown further forward relative to the upper jaw, creating a structural mismatch beyond tooth position. Mild skeletal underbites in growing patients can often be improved with braces combined with growth-modification appliances. Severe skeletal underbites in adults sometimes require corrective jaw surgery alongside orthodontics for full correction.
Most underbite cases have a combination of both components. The clinical evaluation, including X-rays and bite analysis, determines which factor is driving the problem.
Treatment Timelines by Severity
Severity is the single biggest driver of how long underbite correction takes.
Mild underbites with a primarily dental cause typically resolve in 18 to 24 months with braces and consistent elastic wear. The tooth movement required is more targeted and the jaw relationship needs only minor adjustment.
Moderate underbites involving both tooth position and a moderate skeletal component generally run 24 to 30 months. These cases require careful coordination between upper and lower arch movements and sustained elastic wear throughout treatment.
Severe underbites with a significant skeletal component in adults who are done growing represent the most complex cases. Braces alone can improve alignment and function, but when the jaw bones are substantially misaligned, surgical orthodontics combined with braces is often the only way to fully correct the bite. The typical sequence is 12 to 18 months of pre-surgical braces, the surgery itself, and 6 to 12 months of post-surgical finishing braces. Total treatment time in these cases runs approximately two to three years.
How Age Changes the Approach and the Timeline
Age shapes both the treatment options available and how quickly the case can move.
Children Ages 7 to 10
The upper jaw sutures remain open and responsive to force during this window, making it the ideal time for growth-modification treatment. An orthodontist may recommend a palatal expander combined with a reverse-pull headgear that applies forward traction to encourage upper jaw growth while restraining lower jaw growth. This type of early care falls under dentofacial orthopedics, which guides jaw development before all permanent teeth have erupted.
Phase One treatment typically runs 9 to 18 months, followed by a monitoring period while remaining permanent teeth erupt. Phase Two braces usually begin in the early teen years and last a further 12 to 24 months. Early intervention addresses the skeletal problem during growth, often simplifying what follows. The two-phase treatment page explains how both phases connect.
Teenagers Ages 11 to 16
Some jaw growth continues during the early to mid-teen years, which allows for a degree of growth guidance. Teenagers who did not receive Phase One treatment can still be treated effectively with braces and Class III elastics. Treatment typically runs 18 to 30 months depending on severity.
Elastic compliance is the most significant factor in keeping teenage treatment on schedule. Elastics need to be worn 20 to 22 hours per day. Removing them consistently extends treatment and reduces the correction achieved.
Adults
Once jaw growth is complete, growth modification is no longer possible. Adult underbite treatment with braces alone, for primarily dental or mildly skeletal cases, typically runs 18 to 36 months.
Adults with significant skeletal underbites who want full correction should expect a combined orthodontic and surgical plan. The typical sequence is 12 to 18 months of pre-surgical braces, the surgery, and 6 to 12 months of post-surgical finishing braces, totalling approximately two to three years.
The Role of Elastics in Underbite Correction
Class III elastics are the primary tool for correcting an underbite with braces once brackets are in place. These small rubber bands hook from the lower front teeth to the upper back teeth, gradually pulling the upper teeth forward and the lower teeth backward.
Elastics need to be worn 20 to 22 hours per day, removing them only for eating and brushing. The correction they produce is cumulative and depends entirely on consistent wear. Removing them frequently resets progress. Inconsistent elastic wear is one of the most common reasons underbite treatment runs longer than projected, particularly in teenage patients.
What the Process Looks Like From Start to Finish
The first appointment involves a full clinical assessment including X-rays, photographs, and bite measurements. The orthodontist determines whether the underbite is dental, skeletal, or a combination, assesses severity, and develops a treatment plan with a realistic projected timeline.
Braces are placed at the second appointment. Metal braces are often recommended for underbite correction because they handle the sustained and precise forces the treatment requires. Elastics are typically introduced once the initial alignment phase is underway and need to be worn 20 to 22 hours per day from that point.
Adjustment appointments happen every four to eight weeks. Wire changes, elastic instructions, and progress checks all take place at these visits. Attending consistently matters because each appointment advances the plan.
Patients with moderate underbites often notice visible change in their bite around the six to nine month mark. Full correction takes the complete duration of treatment.
Retainers are fitted once braces come off. Underbite cases carry a higher relapse risk than standard crowding corrections. Long-term retainer wear is standard for underbite patients.
Frequently Asked Questions
Can braces fix an underbite without surgery? For mild to moderate underbites that are primarily dental in nature, braces can correct the problem without surgery. In growing patients, braces combined with growth-modification appliances can also address moderate skeletal underbites. Severe skeletal underbites in adults typically require surgery for complete correction.
What is the best age to treat an underbite? Early evaluation by age 7 is recommended by the American Association of Orthodontists and the Canadian Association of Orthodontists. Treatment does not always begin at age 7, but early evaluation identifies whether growth-modification is possible and when the ideal window for intervention falls.
How long do elastics need to be worn for underbite correction? Class III elastics need to be worn 20 to 22 hours per day, removing them only for eating and brushing. Consistent wear is directly tied to how effectively the bite corrects and how long treatment runs.
Will the underbite come back after braces? Relapse is possible, which is why retainer wear is non-negotiable for underbite patients. The risk of shifting back is higher with underbite corrections than with standard crowding treatment. Long-term retainer wear protects the result.
Can teenagers get underbite correction with braces? Yes. Some jaw growth continues into the mid-teens, which still allows for a degree of growth guidance. Treatment typically runs 18 to 30 months depending on severity and elastic compliance.
Get a Treatment Timeline Built Around Your Underbite
General timelines give you a starting point, but the range for underbite treatment is wide enough that a general estimate only goes so far. The actual timeline depends on whether the underbite is dental or skeletal, how severe the jaw discrepancy is, your age, and what treatment approach fits your situation.
At Oasis Orthodontics in Markham, Dr. Khushee Sharma-Fung personally assesses every patient, reviews jaw structure and growth stage, and gives a clear, specific treatment recommendation. Book your consultation and get an honest picture of what treatment involves and how long it will take.