<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>ex-24.txt
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>
<PAGE>

                                POWER OF ATTORNEY

     KNOW ALL BY THESE PRESENTS, that the undersigned hereby constitutes and
appoints David Aviezer, Ph.D., MBA and Yossi Maimon the undersigned's true and
lawful attorney-in-fact to: (i) execute for and on behalf of the undersigned,
Forms 3, 4, and 5 in accordance with Section 16(a) of the Securities Exchange
Act of 1934, as amended and the rules thereunder in connection with the
undersigned's holdings of and transactions in securities issued by Orthodontix,
Inc., a Florida corporation (the "Company"); (ii) do and perform any and all
acts for and on behalf of the undersigned which may be necessary or desirable to
complete and execute any such Form 3, 4, or 5 and timely file such form with the
United States Securities and Exchange Commission and any required stock exchange
or similar authority, including the American Stock Exchange and (iii) take any
other action of any type whatsoever in connection with the foregoing which, in
the opinion of such attorney-in-fact, may be of benefit to, in the best interest
of, or legally required by, the undersigned, it being understood that the
documents executed by such attorney-in-fact on behalf of the undersigned
pursuant to this Power of Attorney shall be in such form and shall contain such
terms and conditions as such attorney-in-fact may approve in such
attorney-in-fact's discretion.

     The undersigned hereby grants to such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact's substitute or
substitutes, shall lawfully do or cause to be done by virtue of this power of
attorney and the rights and powers herein granted. The undersigned acknowledges
that the foregoing attorney-in-fact, in serving in such capacity at the request
of the undersigned, is not assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934, as amended.

     This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorney-in-fact.

     IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of March 11, 2007.

                                                  /s/ Iftah Katz
                                                  -----------------------------
                                                  Name: Iftah Katz

</TEXT>
</DOCUMENT>
