I thought you might be interested in a few good recent articles combining lip repositioning and crown lengthening surgeries. This can be useful for patients with anterior veneers or crowns:
Click here: Modified Lip Repositioning Combined with Crown Lengthening. 2017
Click here: Lip Repositioning to Eliminate the Gummy Smile. Inside Dentistry. Mahn. 2017
Click here: Eliminating Gummy Smile. Clinical Sciences. Simon. 2007
Feel free to comment with your own experiences with these types of procedures.