McKinney P, Tresley G
Plast Reconstr Surg. 1983 Jul;72(1):27-31. doi: 10.1097/00006534-198307000-00006.
Following augmentation mammaplasty, 169 patients with saline and silicone-gel implants placed in the subglandular position were observed over a period of 10 years. It was found that the palpable capsule rate in patients with gel implants was 36 percent; in patients with inflatable implants it was 24 percent. Of the total number of patients in the study who received inflatable implants, deflation occurred in 15.5 percent.