Musannaf Ibn Abi Shayba 18:257

Abu Bakr narrated to us, he said: Ibn Numayr narrated to us, from Yahya bin Sa’id, from Sa’id bin al-Musayyib, that ‘Umar bin al-Khattab decreed regarding what is at the front of the mouth [to be] five obligatory payments, and that is fifty dinars, the value of each obligatory payment being ten dinars. And regarding the molars, [the compensation is] a camel for each. Yahya mentioned that what is at the front of the mouth are the central incisors, the lateral incisors, and the canines. Sa’id said: Then when it was the time of Mu’awiyah, and his molars were injured, he said, "I am more knowledgeable about the molars than ‘Umar," so he decreed for them five obligatory payments. Sa’id said: If the entire mouth were injured according to the decree of ‘Umar, the blood money would decrease, and if it were injured according to the decree of Mu’awiyah, the blood money would increase. And if it were up to me, I would have placed two camels for each molar.