Yes, you can include premiums for supplemental, dental and long term care insurance as medical expenses if you paid them during the year.  (Do not include pre-tax amounts listed on your W2).

You asked 2 questions. 
1. Premiums for long term care.  A portion can be a medical expense deduction with the amount depending on your age. 
2. Insurance premiums for dental expenses is deductible as a medical expense as well. 

You can only deduct an amount of total medical expenses greater than 7.5 percent of your AGI and you must itemize rather than take the standard deduction.