How Can I Smile More Attractively?

The Golden Proportion Myth

One of the most repeated claims in cosmetic dentistry marketing is that the most attractive smiles follow the “golden proportion” — a mathematical ratio of 1.618 applied to relative tooth widths. A systematic review and meta-analysis screened more than 566 initial search results down to six studies that actually met inclusion criteria for testing this claim rigorously, and its conclusion was direct: evidence supporting the existence of the golden proportion in natural smiles is lacking, and the existence of the golden proportion in dentistry is, in the review’s own words, a myth and not a fact. The same review found tooth dimension proportions vary meaningfully by race, ethnicity, and sex, meaning a single universal numeric ratio isn’t empirically grounded in natural human dentition at all. This is a genuine case of a marketing claim not holding up against the best available evidence, despite how often it’s repeated as settled fact.

Gum Display: What the Data Actually Shows

How much gum tissue shows when you smile — sometimes called a “gummy smile” when there’s a lot of it — is a genuinely contested variable rather than one with a fixed ideal number. A 2023 study of 320 Saudi Arabian raters, split between 138 dental professionals and 182 laypeople, had participants rate digitally altered smiles with gingival display manipulated from 4mm of gum coverage to 4mm of gum exposure in 1mm increments. Dental professionals rated a 1mm low lip line, meaning minimal gum show, as most attractive for both female and male smiles. Laypeople largely agreed for male smiles but preferred slightly more gum show (2mm) for female smiles. Notably, professionals and laypeople actively disagreed on zero gum show at all: 59 percent of professionals rated a fully gum-free smile as attractive, while nearly half of laypeople rated the identical image as unattractive. A separate, more recent study of 40 evaluators similarly found that zero millimeters of gum display was rated most favorable by both dentists and laypeople, with 2 to 3mm of display rated as the least attractive amount by both groups. The honest synthesis across both studies: minimal gum display is consistently preferred over a pronounced “gummy” smile, but there’s no single universal millimeter number that qualifies as “the” ideal — it shifts by population sampled and by whether the rater is a trained professional or a layperson.

Buccal Corridor: The Smile-Width Factor

The “buccal corridor” refers to the dark negative space visible at the corners of the mouth between the teeth and the inner cheek when you smile. The same recent 40-evaluator study found both dentists and laypeople strongly preferred smiles with little to no visible buccal corridor, with progressively larger corridor space rated as progressively less attractive by both groups. This is broadly consistent with older orthodontic literature that has debated for well over a decade exactly how much this specific factor matters, with some research in that broader literature suggesting the buccal corridor’s effect size on perceived attractiveness may be smaller than that of the smile arc or gum display — a real but comparatively minor factor rather than the dominant one some marketing implies.

Smile Arc: The Factor With the Clearest Evidence

The smile arc describes the curve formed by the edges of the upper front teeth relative to the curve of the lower lip when smiling. Across the smile-esthetics literature, a “consonant” smile arc — one that curves in parallel with the lower lip — is consistently rated as more attractive than a flat or reverse (“nonconsonant”) arc. The same 40-evaluator study found consonant arcs rated meaningfully more attractive than nonconsonant ones by both dentists and laypeople, with dental professionals penalizing a flat or reverse arc even more heavily than laypeople did. Of all the individual factors examined in the smile-esthetics research, the smile arc shows some of the most consistent agreement across studies and rater groups.

Facial Symmetry, Reconsidered

Foundational research on facial attractiveness established a real correlation between facial symmetry and perceived attractiveness. But more recent work examining study methodology found this effect is highly sensitive to how researchers actually test it: studies using artificially mirrored, perfectly symmetric composite faces — which tend to look subtly unnatural — can produce lower attractiveness ratings than studies comparing real faces with their natural, mild degree of asymmetry. In other words, perfect, artificial symmetry isn’t what the evidence actually supports as most attractive. Natural near-symmetry, which is what essentially every real human face has, correlates modestly with attractiveness ratings, but a person’s normal, everyday facial asymmetry isn’t the aesthetic deficit that some marketing framing implies.

Why Genuine Smiles Read as More Attractive

A meta-analysis of research on smile authenticity found that genuine smiles — technically called Duchenne smiles, which engage the orbicularis oculi muscles around the eyes, producing the visible “eye crinkle” — are perceived as more authentic and positive than posed smiles that only involve the mouth. This is a mechanistic point worth taking seriously alongside all the dental and orthodontic factors above: a technically well-aligned smile that looks posed and doesn’t engage the eyes reads differently to observers than a less “perfect” smile that’s genuinely felt. The eyes are doing real perceptual work here, not just the teeth.

Do This, Not That

Steps for a More Attractive Smile, Evidence-First

1. Assess your smile arc

   Notice whether your upper front teeth curve with your lower lip (consonant) or appear flat/reversed — this is one of the more consistently supported factors.

2. Evaluate gum display honestly

   Minimal gum show is generally preferred, but there’s no single perfect number — don’t chase an extreme (zero) if it isn’t natural for your anatomy.

3. Consider buccal corridor only as a secondary factor

   It matters less consistently than arc or gum display in the research.

4. Practice genuine, eye-engaging smiles

   A Duchenne smile is rated as more attractive and authentic independent of any dental work.

5. Consult a professional for individualized advice

   If considering orthodontic or cosmetic work, ask specifically which factors they’re optimizing and why, given how much rater disagreement exists in the research.

The Self-Esteem Connection

A growing body of cross-sectional research links perceived smile and dental aesthetics to self-esteem scores in both adolescents and adults, supporting the idea that smile appearance carries a real measurable psychosocial impact. It’s worth being honest about the limits of this research, though: most of it is correlational rather than experimental, meaning it shows an association between smile aesthetics and self-esteem without proving that a cosmetic intervention causes an improvement in self-esteem — a notably weaker claim than what cosmetic dentistry and orthodontic marketing often implies.

When to See a Dentist or Orthodontist

A consultation is worth pursuing if you have a specific, identifiable concern — a flat or reversed smile arc, gum display that bothers you specifically, or alignment issues — rather than a vague sense that your smile should look different. It’s also worth raising the research on rater disagreement directly with your provider: ask what specific outcome they’re optimizing for, and whether that matches what you personally find attractive, since professional and lay preferences don’t always align, particularly around gum display and symmetry.

What This Article Can’t Tell You

Frequently Asked Questions