We’re going to reach out to clinics for further clarification, but here is my understanding:
FYI for other readers – sutures are stitches, suturing is stitching.
The short answer: Buried sutures (tying or stitching together soft tissue under the skin) are used for the majority non-incisional double eyelid surgery today, but all the names you see like Seven Lock, Natural Adhesion, Consecutive non-incision, Single-knot non-incision, etc… are the many different techniques and subtle intricacies of how to perform those buried sutures. Some methods are argued to be more superior to others.
The long answer:
Non-incisional double eyelid surgery was first introduced back in 1896, so over the past 100+ years, there have been a lot of advances in the methods of suturing (the knots, quantity of sutures, which layers of soft tissue to tie, where and how to tie them, etc..).
The simple method involved one to two sutures, but the likelihood of the fold becoming undone was high, then clinics started offering different methods with 3 sutures, and then some offered more security through 5 sutures, and ID hospital offers 7 (i.e, Seven Lock). All methods are essentially considered non-incisional buried sutures, but with variations in technique and quantity of sutures, so they are labeled as different procedures.
Most modern day non-incisional double eyelid surgery involves buried sutures (stitching/tying and knotting that happens underneath the eyelid with minimal entry and exit piercing and knotting above the top layer of the skin).
Natural adhesion is a method that seems to add extra technical steps. That technical step according to Grand Plastic Surgery’s natural adhesion method is the following:
“The natural adhesion method starts by inducing adhesion between upper eyelid skin and the muscle that elevates the upper eyelid through small incision holes. After inducing the adhesion, the surgery will be completed by threading (suturing) outer upper eyelid and the membrane that lines the inner surface of the eyelids.”
Note: It’s best to confirm with a doctor, which method works best for you. Usually people with thin eyelid skin are the best candidates for non-incisional.