TORONTO (UPI) -- Patients looked almost nine years younger than they actually were after facial cosmetic surgery, researchers in Toronto found.

Dr. Nitin Chauhan of the University of Toronto and colleagues attempted to quantify the change in perceived age, which may provide objective evidence of the success of surgical intervention and help in patient counseling.

The study involved 60 patients -- 54 of them women who ranged in age from 45 to 72 -- and divided them into three groups. The first group had face and neck lifts, the second had face and neck lifts along with upper and lower blepharoplasty -- eyelid work -- while the third group had face and neck lifts, eyelid work and forehead lifts, Chauhan said.

Volunteers from a class of medical students estimated patients' ages from photographs.

"Adjusted means demonstrated that, on average, raters estimated patient ages to be about 1.7 years younger than their chronological age before surgery but 8.9 years younger than their chronological age after surgery," the researchers said in a statement.

However, the change in perceived age varied based on the specific procedures performed.

The study published in the Online First by the Archives of Facial Plastic Surgery found for the first group of patients, the mean change in perceived age was 5.7 years; for the second group it was 7.5 years; and for the third group it was 8.4 years. Overall, the mean change in perceived age difference was 7.2 years.