Natural breasts fall to the side when a patient lies down, so it's not unusual to see an augmented breast do the same. However, if the implants are sliding to the sides more than the native breast or it is causing a hollowing near the breast bone, then it may be that:1. Your implants may be too narrow for your chest wall and/or2. Your pocket may be too large toward the sides for the implants selected.Correction of these issues can include upsizing implants, changing implant styles, pocket revision/capsulorrhaphy, and other options, depending on the findings on physical exam during consultation. It also appears you have had a lift or reduction, which may mean that you have loose breast skin that is easily stretched and needs to be revised to tighten the envelope further.