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                                                                     EXHIBIT 5.1


               [LETTERHEAD OF WALLER LANSDEN DORTCH & DAVIS, PLLC]




                                 August 6, 2001


Board of Directors
Orthodontic Centers of America, Inc.
3850 N. Causeway Boulevard, Suite 1040
Metairie, Louisiana 70002

                  Re:      Registration Statement on Form S-4

Ladies and Gentlemen:

         We are acting as counsel to Orthodontic Centers of America, Inc., a
Delaware corporation (the "Company"), in connection with the registration under
the Securities Act of 1933, as amended, of 2,460,745 shares of common stock,
$0.01 par value per share (the "Shares"), of the Company, pursuant to the
above-referenced registration statement (the "Registration Statement"). As such
counsel and in connection with this opinion, we have examined and relied upon
such records, documents and other instruments as in our judgment are necessary
or appropriate in order to express the opinions hereinafter set forth, and have
assumed the genuineness of all signatures, the authenticity of all documents
submitted to us as originals and the conformity to original documents of all
documents submitted to us as certified or photostatic copies.

         Based upon and subject to the foregoing and such other matters as we
have deemed relevant, we are of the opinion that the Shares, when issued and
delivered in the manner and on the terms described in or incorporated by
reference into the Registration Statement (after the same is effective), will be
duly authorized, validly issued, fully paid and non-assessable.

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and further consent to the reference to us under the
caption "Legal Matters" in the prospectus included in the Registration
Statement.

                                        Very truly yours,


                                        /s/ WALLER LANSDEN DORTCH & DAVIS, PLLC