David A. Smith, MD, of St. Louis County told his patients that the man performing their Botox injections last year was a physician's assistant. But the man, identified as "G.M.," was not licensed in any medical field and was unqualified to give the injections, according to a disciplinary settlement released this week by the Missouri Board of Registration for the Healing Arts. Smith passed the man off as a physician's assistant to patients, sales representatives and office staff, a violation of Missouri's medical codes. Smith also gave patients half-doses of flu vaccine under the skin instead of a full dose into the muscle, according to the settlement. The healing arts board placed Smith on probation for three years. He can continue to practice medicine but agreed to unannounced visits from board staff to check on his compliance. Smith works for the Visiting Physicians Association in Brentwood and Reflections medical spa at Mario Anthony's salon in Chesterfield.