Violin family instruments have their tops and backs glued onto the rib structure using hyde glue which is a strong brittle glue. Sometimes if the weather changes a seam will need to be re-glued. It's always better to have one of your seams open up than to have a crack develop.
Violin Repair: Here are some general prices for gluing seams.
Violin Seam Gluing
Viola Seam Gluing
Cello Seam Gluing
Bass Seam Gluing