"It appears that Britney said, 'Hit Me Baby One More Time' to her plastic surgeon!" Dr. Youn — a top plastic surgeon who has never treated Spears — told Radar.
"Her cheeks look quite plump, possibly due to injections of a filler like Voluma."
But Dr. Youn also suggests weight gain or an allergic reaction may be to blame.
"Another possible cause could be an allergic reaction to a medication or food, or major weight gain," he said.
"If she's had actual filler injections, hopefully she had them recently and is still swollen. Britney usually looks really good, and as a board-certified plastic surgeon I would recommend clean living to her over any actual fillers, given as young as she is."
And Dr. Norman Rowe agrees, suggesting the singer may have used Botox.
"It appears they Britney has had fillers placed in her cheeks to provide a lift and her forehead looks like Botox has been at work to smooth out any wrinkles," Dr. Rowe, who has never treated Spears, told Radar.
In 2013 Spears, 32, admitted to visiting Beverly Hills plastic surgeon Dr. Raj Kanodia saying he "does fun stuff to me sometimes — I've had lip injections before."
What do you think of Britney's new look — a filler flub, or top-notch needle work? Sound off in the comments below…