How did Lord Ganesha lose his tooth?

According to Bramhanda purana Ganesha blocked his way. Parshuram, furious at being stopped by a small boy, dared him to a fight. Ganesha accepted the challenge. Parshuram attacked with his axe. Ganeshastopped the axe with one of his teeth. The power of Parshuram's axe broke ganesha’s tooth. read more

It says Lord Ganesha broke his own tusk for YOGADANDA. Chapter 10 "Shiva Swallowing Poison" of Skanda Purana says He (Ganesha) pulled out his own huge tooth for sake of "Yogadanda" (the mystic wand of Yogic practice) and held it in his hand. read more

Parashuram was an incarnation of Lord Vishnu who had defeated the evil king Kartavirya Arjuna. He had done this with the blessings of Lord Shiva. The legendary axe known as ‘Parashu’ was used by Parashuram to slay his enemy, and avenge the killing of his father Jamadagni. read more