I am both a plastic surgeon and an attorney who handles medical malpractice cases. If you believe a plastic surgeon has committed malpractice, you can file a complaint against him with your state medical board, and/or you can also consult with an attorney about the possibility of filing a medical malpractice suit. A lay person is not legally competent to determine whether there has been malpractice. A qualified expert is needed to determine whether there has been malpractice. Most of the times a patient thinks there has been malpractice, a review by an expert will determine that there has been no malpractice.
If you file a complaint with the state medical board, the board will discipline the doctor if it finds the doctor violated the regulations of the medical board. It is not up to the state medical board to determine whether there has been malpractice or to discipline the doctor just because he has committed malpractice. A doctor may have committed malpractice without violating the medical board's regulations. In that case, no action will be taken by the medical board. However, if a doctor committed malpractice while also violating a regulation of the medical board, the board will discipline the doctor for violating its regulations, but not for committing malpractice.
If you have serious concerns as to the conduct of a physician, every state has an office of professional misconduct, known by a variety of names. However, without knowing more about what transpired, it would be inappropriate to encourage you to do so as opposed to sharing your concerns with more specifics. Best to you.