UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934

                              (Amendment No. ___*)


                      Orthodontic Centers of America, Inc.
         --------------------------------------------------------------
                                (Name of Issuer)


                          Common Stock, $.01 par value
         --------------------------------------------------------------
                         (Title of Class of Securities)


                                   68750P 10 3
                     ---------------------------------------
                                 (CUSIP Number)




*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).





CUSIP NO.: 68750P 10 3       13G                 Page 2 of 5 Pages


1  NAME OF REPORTING PERSON
   S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

   Denver Investment Advisors LLC
   I.R.S. Identification Number: 84-1284659
- -----------------------------------------------------------------

2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
   (a) [ ]
   (b) [ ]
- -----------------------------------------------------------------

3  SEC USE ONLY
- -----------------------------------------------------------------

4  CITIZENSHIP OR PLACE OF ORGANIZATION

   Colorado
- -----------------------------------------------------------------
               5  SOLE VOTING POWER:           1,506,000
               --------------------------------------------------
   NUMBER OF
    SHARES     6  SHARED VOTING POWER:         None
 BENEFICIALLY  --------------------------------------------------
   OWNED BY
   REPORTING   7  SOLE DISPOSITIVE POWER:      2,295,500
    PERSON     --------------------------------------------------
     WITH
               8  SHARED DISPOSITIVE POWER:    None
- -----------------------------------------------------------------

 9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
    PERSON

    2,295,500
- ------------------------------------------------------------------

10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES
    CERTAIN SHARES
- ------------------------------------------------------------------

11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

    5.1%
- -----------------------------------------------------------------

12  TYPE OF REPORTING PERSON

    IA
- -----------------------------------------------------------------




CUSIP NO.: 68750P 10 3       13G                 Page 3 of 5 Pages

ITEM 1.
  (a)  NAME OF ISSUER:

       Orthodontic Centers of America, Inc.

  (b)  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:

       5000 Sawgrass Village, Suite 25
       Ponte Vedra Beach, FL 32082

ITEM 2.
  (a)  NAME OF PERSON FILING:

       Denver Investment Advisors LLC

  (b)  ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

       1225 17th Street, 26th Floor
       Denver, Colorado 80202

  (c)  Citizenship:

       Colorado

  (d)  Title of Class of Securities:

       Common Stock, $.01 par value

  (e)  CUSIP Number:

       68750P 10 3

ITEM 3. IF THIS STATEMENT IS FILED PURSUANT TO RULE 13D-1(B), OR 13D-2(B), CHECK
        WHETHER THE PERSON FILING IS A:

  (a) [ ] Broker or Dealer registered under Section 15 of the
          Act

  (b) [ ] Bank as defined in section 3(a)(6) of the Act

  (c) [ ] Insurance Company as defined in section 3(a)(19) of the Act

  (d) [ ] Investment  Company  registered  under section 8 of the Investment
          Company Act

  (e) [X] Investment  Adviser registered under section 203 of the Investment
          Advisers Act of 1940




CUSIP NO.: 68750P 10 3       13G                 Page 4 of 5 Pages

  (f) [ ] Employee  Benefit  Plan,  Pension  Fund  which  is  subject  to the
          provisions of the Employee Retirement  Income  Security Act of 1974 or
          Endowment Fund; see Section 240.13d-1(b)(1)(ii)(F)

  (g) [ ] Parent Holding Company, in accordance with Section
          240.13d-1(b)(ii)(G) (Note: See Item 7)

  (h) [ ] Group, in accordance with Section 240.13d-1(b)(1)(ii)(H)

ITEM 4.  OWNERSHIP

         For Denver  Investment  Advisors LLC ("DIA"),  the following sets forth
the  amount of shares  beneficially  owned,  the  percent  of class  owned as of
December 31, 1997,  the number of shares to which DIA has the sole power and the
shared  power to vote or to direct  the vote of the  shares,  and the  number of
shares to which DIA has the sole  power and the  shared  power to  dispose or to
direct the disposition of the shares:

  (a)  Amount Beneficially Owned: 2,295,500

  (b)  Percent of Class: 5.1%

  (c)  Number of shares as to which DIA has:

         (i)  sole power to vote or to direct the vote:

              1,506,000

        (ii) shared power to vote or to direct the vote:

              None

       (iii)  sole power to dispose or to direct the disposition of:

              2,295,000

        (iv)  shared power to dispose or to direct the disposition of:

              None

ITEM 5.  OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

         This item is not applicable.




CUSIP NO.: 68750P 10 3       13G                 Page 5 of 5 Pages

ITEM 6.  OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF
         ANOTHER PERSON.

        Various persons other than DIA have the right to receive or the power to
direct the receipt of  dividends  from,  or the  proceeds  from the sale of, the
common stock of the Issuer.

ITEM 7.  IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY
         WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE
         PARENT HOLDING COMPANY.

         This item is not applicable.

ITEM 8.  IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE
         GROUP.

         This item is not applicable

ITEM 9.  NOTICE OF DISSOLUTION OF GROUP.

         This item is not applicable.

ITEM 10.  CERTIFICATION.

          By signing below the  undersigned  certifies  that, to the best of its
knowledge  and belief,  the  securities  referred to above were  acquired in the
ordinary  course of business and were not acquired for the purpose of and do not
have the effect of  changing  or  influencing  the control of the issuer of such
securities  and were not acquired in connection  with or as a participant in any
transaction having such purposes or effect.

                                    SIGNATURE

         After reasonable inquiry and to the best of the undersigned's knowledge
and belief,  the  undersigned  certifies that the  information set forth in this
statement is true, complete and correct.

Dated:  February 11, 1998     DENVER INVESTMENT ADVISORS LLC

                                  /s/ Kenneth V. Penland
                              By:_____________________________
                                  Kenneth V. Penland
                                   Chairman