are chiropratic services and mouth guard under medical expenses?

Per IRS : 

Medical expenses are the costs of diagnosis, cure, mitigation, treatment, or prevention of disease, and for the purpose of affecting any part or function of the body. Chiropractic treatments fall under this category.

Also,  mouth guard can be considered a medical expense, when prescribed by a dentist for a medical condition.

You can't include medical expenses that were paid by insurance companies or other sources. 

If you itemize your deductions, you can deduct only the part of your medical and dental expenses that exceeds 7.5% of the amount of your adjusted gross income on Form 1040 or 1040-SR, line 11.