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 December 12, 2006.

                                             /s/ Eli Hurvitz
                                             -----------------------------------
                                             Name: Eli Hurvitz