Plans are generally not necessary to get a permit to do mechanical work on a dwelling. You will be expected to briefly describe the work proposed. For example, describe the appliance you intend to install and whether you will be installing a new vent, new ductwork, etc.
It depends on what kind of stitches the dentist used in your mouth. There are two types: stitches that resorb on their own and you don't need to do anything, and the other are stitches for which you see the dentist in about two weeks and he/she removes them. Ask your dentist which type he/she placed in your mouth.
Depending on the suture, dissolving sutures may take anywhere from 5 days to 14 days to dissolve. Warm soaks and topical ointments may speed this process. To achieve the best scar appearance, non dissolving sutures should be run just under the skin from one end of the incision to the other.