Braces can contribute to deeper smile lines, but the effect is small and depends heavily on your treatment plan. The strongest factor is whether teeth are extracted as part of treatment. In cases involving extractions, the nasolabial folds (the creases running from your nose to the corners of your mouth) deepened by an average of 0.72 mm. Without extractions, the change was much smaller, around 0.22 mm. For most people, these shifts are subtle enough that they don’t dramatically alter facial appearance.
How Braces Affect the Tissue Around Your Smile
Your front teeth act like scaffolding for your lips and the surrounding skin. When orthodontic treatment moves those teeth backward, the soft tissue loses some of its underlying support. This is why the area around the nasolabial folds can flatten slightly inward, making existing creases a bit more noticeable.
A 3D imaging study of adult women found that both extraction and non-extraction orthodontic patients experienced some degree of negative change (inward movement) in the nasolabial fold area after treatment. In the extraction group, the upper lip retracted by about 0.93 mm and the lower lip by 1.46 mm. The non-extraction group actually saw the upper lip move slightly forward by about 0.55 mm, which can help maintain or even improve fullness in that region.
The key mechanism is the angle of your front teeth. When incisors are tilted back during treatment, the lips have less to rest against. That said, research using cone-beam imaging found that incisor angle changes of 5 degrees or less had minimal impact on lip thickness, length, or position. Many orthodontic cases fall within that range, which is why most patients don’t notice a significant change in their smile lines.
Extraction Plans Create Bigger Changes
The clearest link between braces and deeper smile lines involves premolar extractions. Removing teeth creates extra space that the orthodontist uses to pull the front teeth backward, which reduces lip support more than non-extraction treatment does.
A study of 160 patients who had four first premolars removed found the nasolabial angle increased by an average of 5.2 degrees, and the upper and lower lips moved back 3.4 and 3.6 mm respectively. That sounds significant, but 80 to 90 percent of those patients ended up with a profile that was either improved or remained satisfactory. Only about 10 to 15 percent of cases resulted in a profile that could be considered excessively flat. Between 5 and 25 percent of the sample, depending on which measurement was used, actually had more prominent lips after treatment, not less.
So while extractions do shift the soft tissue, the outcome depends on where you started. Someone with naturally protruding teeth and lips may actually look better with slight retraction, while someone with a flatter profile to begin with is more likely to notice unwanted deepening of their smile lines.
The Brackets Themselves Play a Temporary Role
While you’re wearing braces, the brackets and wires physically push your lips outward. This can actually mask changes happening underneath, or even temporarily smooth out the nasolabial area by adding volume behind the lips. A study measuring lip position before and after bracket removal found that the lower lip and corners of the mouth moved inward by about 0.4 to 0.56 mm once the hardware came off. The upper lip showed no significant change after debonding.
This means some patients notice their smile lines more after getting braces off, not because the lines suddenly appeared, but because the extra bulk of the brackets was stretching the skin slightly outward during treatment. The change is minor, less than a millimeter, but it can be enough to catch your attention when you’re scrutinizing your face in the mirror post-treatment.
Aging During Treatment vs. the Braces Themselves
Adult patients sometimes wonder whether the smile lines they notice after braces are really from the orthodontic work or simply from getting two years older. It’s a fair question, since collagen loss and skin thinning deepen nasolabial folds naturally over time. Research on this specific overlap found that bone changes over a decade of aging are very limited, and during a typical two- to three-year orthodontic treatment, changes in facial shape are primarily driven by soft tissue movement rather than skeletal aging.
One study noted that certain facial changes observed between the start and end of treatment couldn’t be explained by aging alone, because they appeared in areas directly affected by tooth movement. Still, if you’re in your 30s or 40s, some subtle deepening of smile lines during a two-year treatment window would have happened regardless of braces. Separating the two effects precisely is difficult, but the orthodontic contribution appears to be the dominant factor in the nasolabial region specifically.
Who Is Most Likely to Notice a Difference
Several factors increase the chance that braces will visibly affect your smile lines. Treatment plans involving premolar extractions and significant retraction of the front teeth carry the highest risk. Adults are more susceptible than teenagers because their skin has less elasticity to adapt to changes in underlying support. People with thinner lips or less facial fat have less cushion to absorb the retraction, making even small millimetric shifts more visible.
If you’re concerned, non-extraction treatment plans generally preserve or slightly increase lip fullness. Discussing your profile goals with your orthodontist before treatment starts is the most practical step, since they can evaluate how much retraction your plan involves and what effect that’s likely to have on the surrounding soft tissue. For patients whose front teeth are already well-positioned and don’t need significant backward movement, the risk of noticeable smile line changes is low.