I was diagnosed with HPV16+ OSCC in March 2023. I had TORS robotic surgery April 2023. I had a right neck dissection with all lymph nodes removed and TORS surgery to remove primary tumor of 3cm at base of tongue. . All margins clear. I completed 30 rounds of Proton Radiation. The biggest issue I had was dysphagia and Not being about to swallow (eat or drink) for about two weeks after surgery. I understand He is doing mouth, tongue and swallowing exercises? If you have a Speech therapist they can help you with this? I think the chin into my chest and HARD swallow helped me initially get a few things down and then It got easier to swallow. I had alot of mucous/saliva where you feel like you are almost drowning and It was hard to eat and drink for a month or so. Then Started with soft foods and Boost drinks. Soup, eggs, bananas, etc. You actually "forget" how to swallow once you go awhile without doing it. He will need to force himself and work hard at it . Good luck!