When you put your tongue to the roof of your mouth at the alveolar ridge, you complete an energetic circuit called the "Micro-Cosmic Orbit"
As a T'ai Chi and Qigong Instructor for almost 25 years, I know that doing this enables you cultivate or pull in more Chi (universal life force energy). It occurred to me that maybe we should be doing this while running Reiki (meaning channeling it when doing Reiki sessions on others or on ourselves). We do it when attuning someone but I wondered what the benefit of doing it while running Reiki during a Reiki session would be. So I am going to experimenting with it and invite you to do the same!