In most cases, I don’t think that it is prudent to use high-profile or moderate-profile implants (saline or silicone) to correct sagging breasts, as this is not the solution. If you truly have breast ptosis or sagging breasts, you should do a breast lift with or without implants. Obviously, if patients want a lift and more upper fullness they should do a lift with (moderate-profile) implants in most cases.
The problem with high-profile implants is that they have not been adequately studied and may have much higher incidence of breast tissue and glandular thinning and subsequent long-term rippling effects, whether they are silicone or saline, although this has not been studied extensively.