On Medicare but pay a monthly premium to supplemental insurance

I keep seeing the bold-lettered statements about how much you can deduct for insurance medical expenses that makes me think I'm missing something here...

We do have the Medicare Part B premiums deducted from my SS benefits, but I also pay a monthly premium for a supplemental plan from an insurance company for my spouse and I. We have a dental plan that we also pay premiums for.

Do the monthly payments to the supplemental insurance company count as a deduction?