The VAST majority of patients won't even noticed that you are not an MD ... as long as you are "doctor" to them. Ask any practicing DO or any DO students on clerkship how many times the patients have asked about their "degree".
Also keep in mind the laws and regulations of each state.
In Pennsylvania
§ 25.212. Professional advertising.
(b) Advertising, letterhead, publications or transmissions shall designate or indicate the licensees school of medical practice by the term D.O., doctor of osteopathy, osteopathic physician or osteopathic physician and surgeon.
Authority
The provisions of this § 25.212 issued under section 16 of the Osteopathic Medical Practice Act (63 P.S. § 271.16); and section 902(b) of the Health Care Services Malpractice Act (40 P. S. § 1301.902(b)).
http://www.pacode.com/secure/data/049/chapter25/subchapDtoc.html