Ganesha is also known as Ekdanta, or the one with one tooth, because one of his tusks is broken. There are many popular legends associated with his broken tusk.
According to Padma Purana, one day sage Parashurama came to visit Shiva. However, Ganesha would not allow Parashurama in, for his father's sleep would be disturbed. When Parashurama insisted he be permitted entry, a fight broke out. In the course of their struggle, Parashurama threw his axe at Ganesha. This axe had been given to Parashurama by Lord Shiva. Recognizing the axe and out of reverence for his father, Ganesha refused to intercept the weapon. He bowed and took its impact on one of his tusks, which broke.
Ganesha, the embodiment of wisdom, is also depicted as a scribe to whom sage Vyasa dictated the Mahabharata. He is accepted as the god of learning and the wisdom. Sage Vyasa, the author of Mahabharata, wanted to dictate the verses of Mahabharata to someone who was capable of writing extremely fast, and without mistakes. Lord Brahma decided that Lord Ganesh was the only person equal to this great task. Vyasa told Ganesha that he would dictate the poem very fast and that Ganesha must take down all the verses without mistakes. Ganesha threw a challenge in return that he would write as fast as Vyasa dictates and that too correctly, but when dictating, Vyasa should not stop till he complete the entire Mahabharata. The dictation began, but in the rush of writing Ganesha's feather pen broke. He broke off a tusk and used it as a pen so that the transcription could proceed without interruption, permitting him to keep his word.! ✨🐘🌀💛🍚🕉❤️📿🎨💜🙏
Om Shri Ekdantaya Namah