AMERICAN DENTAL PARTNERS, INC. SECURITIES LITIGATION
KCC

IN RE AMERICAN DENTAL PARTNERS, INC. SECURITIES LITIGATION

CASE NO. 08-cv-10119-RGS

UNITED STATES DISTRICT COURT

DISTRICT OF MASSACHUSETTS

SPECIAL NOTICE TO SECURITIES BROKERS AND OTHER NOMINEES

If you purchased the securities of American Dental Partners, Inc. during the period from February 25, 2004 and December 13, 2007, inclusive (ADPI common stock traded during this period under NASDAQ ticker symbol: ADPI; CUSIP: 025353103), for the beneficial interest of a person or organization other than yourself, the Court has directed that, WITHIN SEVEN (7) DAYS OF YOUR RECEIPT OF THIS NOTICE, you either (a) provide to the Claims Administrator the name and last known address of each person or organization for whom or which you purchased ADPI common stock during such time period or (b) request additional copies of this Notice and the Claim Form, which will be provided to you free of charge, and within seven (7) days mail the Notice and the Claim Form directly to the beneficial owners of the ADPI common stock. If you choose to follow alternative procedure (b), the Court has directed that, upon such mailing, you send a statement to the Claims Administrator confirming that the mailing was made as directed. You are entitled to reimbursement from the Settlement Fund of your reasonable expenses actually incurred in connection with the foregoing, including reimbursement of postage expense and the cost of ascertaining the names and addresses of beneficial owners. Those expenses will be paid upon request and submission of appropriate supporting documentation. All communications concerning the foregoing should be addressed to the Claims Administrator:

American Dental Partners, Inc. Securities Litigation
c/o Administar Services Group LLC
P.O. Box 56380
Jacksonville, FL 32241-6380