I haven't heard of tongue biting being a symptom, but I do grind my teeth and was scared to sleep when I couldn't use my bite guard post op. Numb tongue + teeth grinding is scary. I would have him call his dentist.

Lisa

SCC Tongue T1N0M0\Dx 3-10-03
Hemiglossectomy, alloderm graft, modified neck dissectomy 4-14-03
3 Year Survivor!