If you dream that your mouth is stopped by a gag, it denotes that you will soon thereafter be kissed by a pretty girl. To a young girl such a dream predicts that she will soon see some gentleman who cakes her fancy, and perhaps will fall in love with him.
Dream dictionary: pins in mouth dream meanings
When you dream about the jasper, then such dream denotes to pleasant experience in your waking life, because it will bring long and healthy life. If you see the jasper that is in your mouth, then such dream represents some important message that you will find out.