Up until a few months ago I'd had terrible rhinitis for a couple of years. It only really affected me at night and meant that as soon as I lay down I couldn't breath through my nose. Sleeping with your mouth open to breath dries your mouth out an leaves you feeling like it's been coated in shellac by the morning, It can even be painful. I used to wake in the night with what felt like the world's worst tongue bite. And that was before I took up the pipe. I even had bleeding gums and blood in my sinuses.
If you're in any way susceptible to rhinitis, smoking, whether you inhale, retrohale of just puff, is highly likely to exacerbate it. And if you're sleeping with your mouth open you'll wake with a mouth like the bottom of a parrot's cage. I found the adhesive nasal strips helped. But the problem vanished altogether when I stopped eating processed food. Sounds odd, but it's true. Also, the chronic gum disease I'd had for years disappeared as well. Recently I gave up alcohol too and things have been better still since that.
This all suggests I'd been living with high cellular inflammation without knowing it. The main cause, I believe, was diet, made worse by alcohol. If I hadn't fixed this I doubt I'd have been able to tolerate pipe smoking. As it is, I smoke quite heavily, especially in the evenings, yet I don't get these problems any more. Smoking tobacco isn't good for your mouth health, but in my case it wasn't the cause of my problems because they ceased before taking up the pipe after making other lifestyle changes taking up pipe smoking since then hasn't brought them back.
A bit of mouth clag is to expected from smoking tobacco but with good oral hygiene it shouldn't be excessive. But I guess what I'm trying to say is, if it is excessive, it could be that taking up pipe smoking, rather than causeing these problems, could be revealing another underlying cause.