In part III chapter 8-3, while talking to Gard, Bobbi's lips drew back from her teeth (earlier in the book we learn that all her teeth have fallen out), then a couple of pages (and about 10 minutes of story time) in 8-4 her lips spread in a toothless grin!
Sorry, but I think you got it wrong. In the beginning, she was dreaming that she was losing all her teeth, and when she woke up one of her teeth was missing, then shortly afterwards found in her bed. It was fore-shadowing, man.