A sialogram is performed to diagnose blockage of the salivary flow due to stones or strictures. This examination is done by introducing a very thin tube into the opening of the duct and injecting a small amount of liquid. This probe procedure is done without any anesthesia since it is not too painful. It is a simple procedure usually completed in 30 minutes. Occasionally it can be difficult to the find the duct opening and in those cases the procedure with take longer.