How long does it take for your tooth to grow after you get a surgery for compound odontoma?

Depends: I assume you are asking about a tooth that hasn't erupted because it was being obstructed by a compound odontoma that was removed. It depends on several factors including the age of the patient, the stage of development of the unerupted tooth and the position of the unerupted tooth.

Within months: Once the odontoma is removed the permanent tooth can now resume its normal eruption process.

Need evaluation: Often when odontoma present the associated tooth is congenitally missing. If tooth is present, in good position, well angulated, and the end of the root has not apex infield (matured), there is a small chance that tooth will erupt spontaneously. See an orthodontist about what needs to be done to bring impacted tooth into place.