It's not a regular medical expense. Your dental insurance premiums will be a deduction on page 1 of the federal form 1040 as
Self-Employed Health Insurance. The amount you can deduct is limited to
your net profit in your business. If your business has a loss, you will
not be able to deduct the insurance premiums on the Form 1040. However, you can
claim them as an itemized expense on Schedule A, if you have enough other
medical expenses.
Here is where to enter your medical insurance premiums
if you are self-employed:
https://ttlc.intuit.com/replies/4230299
Also,
here is a link to a good article on Self-Employed Health Insurance
