The internal suture technique alone for synmastia repair is difficult at best to prevent recurrence. Your photos show significant indentation of the skin and what appear to be oversized implants. However, internet evaluations do not supplant an in-person exam. I prefer a multi-step approach to synmastia repair:
Be sure the implants are within the anatomic dimensions of the breast (implant width < breast width), if not - decrease the implant dimensions!
If subglandular, switch to a submuscular pocket (new implant space)
If submuscular, create a neo-subpectoral pocket (new implant space)
Remove any capsule which overlies the sternum or create a capsular "flap" to wall off the sternal space.
Use Strattice or a similar dermal matrix if necessary to prevent migration of the implants over the sternum.
Use internal sutures as necessary without creating external puckering
An external "thong" bra to keep even pressure along the sternum.
As you can see, correction is not a simple "throw some stiches" solution. Even with all of these techniques, synmastia is difficult to correct. The best outcomes are for those patients with subglandular implants who desire smaller implants as switching to a submuscular pocket with appropriate sized implants allows for the easiest and most predictable correction.