Navel Area Tightening Procedure?

For minor skin laxity, you could try the Accent device, which is a RFA (Radio Frquency Ablation) laser. More severe laxity will likely require some open surgical contouring procedure.

I agree with Dr. Di Saia that there is not a great "non scar" option here.
Most involve trying to induce some level of skin tightening.
In my practice patients with these issues sometimes elect for skin excision. Usually these scars can be well camouflaged in the belly button.
Outside of those options ultrasonic or laser lipo with minimal fat removal may give you a more reliable and dramatic improvement compared to Thermage.
I hope this helps.
Steven Williams, MD
Tri Valley Plastic Surgery