What can be done about sudden smile lines and sagging side of mouth? (Photo)

there are many options for treatments in this are with fillers in the lips, folds and around the mouth/chin/jawline.  I suggest lasers to tighten the skin and improve fine lines and texture.  See a filler and laser expert.  Best, Dr. Emer.

I recommend Morpheus 8. Morpheus8 is a non-surgical treatment for full body skin resurfacing, skin tightening, and fat reduction of stubborn areas. It uses minimally invasive fractional radiofrequency energy (RF) to penetrate the skin deeper than other microneedling devices, triggering the skin’s natural healing response to promote skin tightening and lifting. Best of luck, Dr. Nima!

Thank you for your question. If your smile or bite is uneven, you could have malocclusion which could cause TMJ.  TMJ is inflammation of the jaw joint and is usually very painful.  If you have these, you should consult your dentist or oral surgeon.  Although dental issues could contribute to changes around the mouth area, most smile lines are due to aging, although you didn't state your age.   For these issues we have numerous fillers we can use sometimes in conjunction with Botox to treat them.  The common areas treated are nasolabial folds, marionette lines, lips, and chin.  Often we replace volume in the cheeks which is the actual cause of many deep nasolabial folds.  It's difficult to fully evaluate your issues from your partial photo and I recommend you have a live full face assessment.  But see your dentist first!

Thank you for posting a photograph with your questions. Judging from your photograph, you are young, but have the changes that are characteristic of the loss of facial volume, due to facial bone loss. Fortunately, you have a youthful neck and jawline. Your midface is often the first to show signs of facial aging. This loss of volume can be restored using facial volumizers such as Sculptra Aesthetic and Radiesse. The results look natural. The Sculptra Aesthetic lasts up to 2 years and takes approximetly 4-6 weeks to work. Radiesse, which has calcium in it, lasts 9-12 months and works immediately. I recommend that you have a consultation with a Board Certified Plastic surgeon, who has experience injecting these. Best wishes in achieving your goals, Dr. Richard Wellington Swift, MD

A combination of filler, skin tightening and RF Microneedling can help.  I like Fotona Piano mode long pulse ND:YAG skin tightening, filler like Perlane "LIFT" or Juvaderm UltraPlus and RF Microneedling with Intensif or Fractira.