Your tongue remains the same size. It doesn't lose or gain mass. If anything my airway has expanded because I now have the ability to keep my tongue more towards the front of my mouth and away from my throat. I can also stick my tongue out farther, which again, opens up my airway. I'm obviously not going to stick my tongue out for the rest of my life, but its a nice reprieve from the perpetually smaller amount of space in my mouth while the pull back my bottom front teeth in preparation for sleep apnea orthognathic surgery. It did nothing for my forward head posture. I have forward head posture because my mandible is retruded. If I stand tall I essentially cut off my airway. This will be fixed when I have orthognathic surgery.