Thank you for your very astute question! A "68-year-old woman with sun-damaged skin" will definitely not get the same results as a 48 year old woman without so much sun damage, but you should see results with either of the treatments you mention. ThermiTight is more surgical, technically, as it involves injecting the area to be treated with local anesthetic (numbing agent) and then making a puncture in the skin in order to slide the ThermiTight cannula under the skin to heat the tissue from the inside. There is swelling and some pain post-operatively, but most patients do not need to interrupt their usual schedules for recovery, but that also depends upon how much surface area you have treated. The larger the area, the more pain post-operatively. ThermiSmooth or Thermi250 are non-surgical treatments, which are very comfortable and involve no downtime. Usually, these are done as a series of 4 or more treatments spaced 2-4 weeks apart. Both result in better skin tightening than anything I have experienced so far. ThermiTight results are somewhat more dramatic than the non-surgical option, but both work and you should expect to see some definite results. Since you are really only asking about your face, I would recommend ThermiTight to the chin, neck and jowl area, maybe even the midface to cheeks, then Thermi250 for around the eyes. Couple that with toxin (Botox, Xeomin, Dysport), fillers, and microneedling with PRP and you will have the closest thing to a facelift you can get without all the surgery and downtime. See the video below for an idea of what to expect from a ThermiTight procedure.
Combination treatment best
There is no single treatment that is best for tightening the skin and reducing fine lines. Multiple treatments that complement each other give best results. With that said, fractional CO2 laser resurfacing would arguably be the best single treatment for both skin tightening and wrinkle reduction.
Wrinkles/Sun Damage- Fraxel, IPL, Microneedling/PRP
ThermiRF does well for skin tightening but it doesn't replace a face lift or the need for fillers, botox, skin care/lasers. Get a formal antiaging consultation. Best, Dr. Emer.