Indian hedgehog（Ihh）, one of the members of hedgehog protein family, is essential for embryonic development and organ formation. The embryonic growth and pathological changes of temporomandibular joint involve complex processes and attract more and more studies. Recent studies have revealed that Ihh not only participates in the embryonic growth of mandibular condyle but also regulates those processes during post-natal life via the cell-surface receptors patched and smoothened and downstream signal of Gli.
