Texas officials are investigating whether Xerox Corp. allowed dentists to bill millions of dollars in Medicaid payments for work that shouldn't have been covered by Medicaid, the Wall Street Journal reports. 

The state contracts with Xerox to evaluate the necessity of medical procedures that dentists want covered by Medicaid. But the state's Health and Human Services Commission reportedly said that the company may have lacked enough trained staff to make those evaluations. According to a 2008 state audit, the company had just one dentist to evaluate thousands of Medicaid requests.

The probe is part of a broader state effort to examine improper billing by dentists and orthodontists, who state officials believe have charged the Medicaid program for unnecessary work like cosmetic braces and root canals for youth. Last year, the Medicaid program in Texas paid $1.4 billion to dentists and orthodontists -- about four times more than it paid in 2006 -- and in 2010, it spent more on braces than every other state Medicaid program combined, the Journal reports.

Xerox works with Medicaid programs in 36 states plus the District of Columbia, according to the paper.