Over years of use, combined with a gradual loss of the surrounding tissue that once balanced its pull, this muscle can end up dominating the resting expression, even when you’re not frowning at all. There’s also a degree of natural asymmetry in how strongly this muscle acts on each side, which is why one corner sometimes appears more affected than the other. Because the muscles that lift the corners of the mouth (particularly the zygomaticus muscles) don’t strengthen with age the way the DAO’s relative influence increases, the balance of the whole area gradually shifts downward over years, even without any single dramatic change.

The jawbone itself gradually remodels with age — the angle can change slightly, and bone density in the area supporting the lower face reduces somewhat. This provides a subtly different foundation than it did decades earlier, a real if understated contributor to the way the whole lower face, including the mouth corners, settles over time.

This is one of the more technically nuanced neuromodulator treatments, because the DAO sits close to other muscles responsible for genuine smiling and lip movement. Placement that’s too broad or too high risks softening the wrong muscle and affecting your smile rather than just your resting expression — this is why a detailed understanding of the muscle’s exact position, which varies somewhat between individuals, matters more here than in many other injectable treatments. Results generally last three to four months before the muscle’s activity gradually returns.

In some patients, filler placed at the corner of the mouth itself, or along the marionette lines running toward the chin, may help restore some of the lost structural support and soften the fold, without changing the overall shape or size of the mouth. This is often combined with the neuromodulator treatment above, since they address different contributing mechanisms — muscle pull versus volume loss.

However, there is a risk of the filler migrating over the years, creating a puffy appearance in the area.

Thread lifts are not part of my recommended approach for downturned mouth corners. Although they are often marketed as a quick, non‑surgical lift, their effect in this specific area is modest, short‑lived, and mechanically unreliable. The lower face is highly mobile, and threads placed here tend to lose tension early, create asymmetry, or produce visible irregularities as they settle. They also do not meaningfully counteract the true drivers of the problem — DAO muscle dominance, volume loss, and structural descent — which is why results often fade within months.

Beyond limited longevity, threads introduce unnecessary risks: internal tethering, contour distortions, prolonged tenderness, and difficulty performing future treatments in the same region. For these reasons, I do not use threads for mouth‑corner correction and prefer treatments with predictable biomechanics, stable longevity, and a cleaner safety profile.

For more advanced changes — where volume loss and skin laxity are significant, and non-surgical measures would only offer a partial improvement — a lower facelift addresses the jawline and cheek support more comprehensively. This often has a meaningful flow-on effect on the mouth corners as part of repositioning and supporting the broader lower face, rather than treating the mouth corners as an isolated area.

Treatments that improve overall skin quality and thickness around the mouth help the area look less deflated and hollow, and work well alongside whichever structural treatment (filler, thread lift, etc.) is chosen to correct the sagging itself.

Skin Boosters
Injectable hyaluronic acid formulated for hydration rather than volume (e.g., Profhilo, Restylane Skinboosters, Juvéderm Volite) is placed in fine droplets through the superficial dermis around the mouth. Rather than physically lifting tissue, it stimulates fibroblast activity and collagen/elastin production while drawing in water, gradually improving skin elasticity, hydration, and thickness. This helps soften the crepey, thin-looking skin that often accompanies downturned mouth corners, giving the area a plumper, more resilient quality over a course of 2–3 sessions.

RF Microneedling with Specialised Serums
Radiofrequency microneedling (e.g., Morpheus8, Profound) creates controlled micro-injury channels in the dermis while delivering heat energy, triggering collagen remodeling and skin tightening from within. Immediately after treatment, the micro-channels are used to infuse targeted serums — often peptides, growth factors, or additional hyaluronic acid — deeper into the skin than topical application alone would allow. This combination approach improves both skin thickness and firmness, which helps support the corners of the mouth and reduce the appearance of loose, sagging tissue.

Skincare
A consistent topical regimen supports and prolongs the results of in-clinic treatments. Key actives for this area include:

• Retinoids to stimulate collagen turnover and improve skin thickness over time
• Peptides to support structural repair and firmness
• Antioxidants (vitamin C, niacinamide) to protect against further collagen breakdown
• Hyaluronic acid-based moisturizers to maintain hydration and skin plumpness
• SPF as a non-negotiable, since UV exposure is a major driver of collagen loss and skin laxity around the mouth

Laser
Fractional laser resurfacing (non-ablative options like fractional Nd:YAG, or ablative options like fractional CO2/Erbium depending on downtime tolerance) stimulates deeper collagen remodeling and tightens the skin’s surface texture. This can meaningfully improve skin thickness and quality around the mouth, smoothing fine lines and improving elasticity, which complements the effect of structural correction by making the surrounding skin appear healthier and less deflated rather than just repositioned.