[Epona]

Dan, if you have an infection or abscess under the tooth, there could also be a secondary ear infection. There is fluid in the inner ear which, thanks to gravity, helps us to tell which way up we are - and if your ear is infected this can get mucked up, resulting in dizziness.

Alternatively, do you know for sure you have a cavity? Ear infections can also cause toothache. But anyway, it sounds as if your ear may be somehow affected.