WASHINGTON, July 10 (TNSFR) -- The U.S. Department of Justice Drug Enforcement Administration revoked an Oklahoma dentist's controlled substances registration after determining he no longer holds state authority to handle controlled substances in Oklahoma. The agency issued a final order revoking DEA Certificate of Registration No. AA1668803 held by Mark Allen, D.D.S., of Edmond, Oklahoma, after concluding he no longer possesses the state authorization required to prescribe, administer, dispens  more