I used to work in a dental environment (wasn't a dentist) for a few years. I would go back to the dentist and ask for a two week referral. When oral cancer is suspected, a 4-month wait is wholly unreasonable. The current waiting lists for oral surgeons etc are horrendous, and even that 4-month wait could easily be a 6 month wait. Yeah, there are guidelines for a reason, and if what you are saying is true, then they're not being followed. I reside in Scotland, so rules could be different, but i suspect when it comes to this, they aren't. He might have to wait around 3 weeks due to the hefty workloads they have, but 3 weeks ain't 4 months.

Thanks so much for your response  will reach out to GP 

Thanks so much for your response  will reach out to GP