ST Robinson Humphrey lowered its investment rating on Mentor Corp. (MNT

) to hold from buy.

Analyst Ryan Rauch says that based on recent channel checks, Mentor's and Inamed's (IMDC

) breast implant sales growth has slightly decelerated in the second quarter. He lowers Mentor's $50 million second-quarter breast implant estimate to $48.8 million, and Inamed's to $47.4 million. Also, he continues to be concerned over Mentor's penile implant sales growth as competitive impotency drug treatments continue to gain traction and will likely weaken this very profitable business unit. Rauch notes Mentor has been a strong performer, but while he applauds its recent execution and financial performance, he believes the risk/reward scenario is now less favorable.