Before and after: Bristol Palin photographed in 2010 (left) and earlier this month, following her surgery (right). (Gregg DeGuire/Jimi Celeste/AP)

Bristol Palin insists she didn’t have plastic surgery, just work on her jaw to align her teeth properly.

So we turned to an expert: Robert Emery, a Washington oral and cosmetic facial surgeon who seems like a dispassionate observer. (“Is that one of Sarah Palin daughters?” he asked when we called. The dancing teenage mom, we explained.)

Emery studied closeup photos of Bristol taken last fall, before the December procedure, and two weeks ago. His verdict?

“It does not appear she had ‘corrective jaw surgery,’ ” he told us. “Her occlusion, ‘her bite,’ appears normal and well aligned in November of 2010 with no visible changes in April of 2011.” It’s clear to him that she’s undergone “some procedure on her chin, either a genioplasty or a chin implant. It also appears as if she has had liposuction under her jaw, a submental lipectomy.”

In layman’s terms: Sounds like cosmetic work.