(Cover) - EN Showbiz - Ali Lohan may have undergone cosmetic procedures to achieve her new look, a doctor has said.

Plastic surgeon Dr Gary Alter of Beverly Hills, California, believes that Ali's dramatic novel appearance is unnatural. Reviewing recent photos of the 17-year-old model, Gary is convinced that she has enhanced her features through cosmetic injections.

"It's obvious to me that her eyebrows are higher than they were before," Gary told RadarOnline. "There doesn't appear to be much moment on her forehead, and she looks like she has had Botox. Botox can actually raise eyebrows and get some of the wrinkles out."

There has been much speculation surrounding how Ali may have achieved her new look. Although there are differing opinions on whether her facial features have changed, she is noticeably thinner. Ali's father Michael Lohan is unsettled by his daughter's drastic change in appearance.

"It's scary to see my daughter looking like this," Michael said. "Ali was always on the thin side, but seeing how much weight she's lost there appears to be a drastic change that concerns me."

Ali recently signed a multi-year contract with agency NEXT Model Management. (C) Cover Media