Amr bin Shu'ayb (may Allah have mercy on him) said that Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) gave a ruling concerning the eyebrow: when it is injured so that its hair goes and the bone is exposed by the wound, there are ten camels for it (as for two bone-exposing wounds).
Ibn Wahb (may Allah have mercy on him) said: Imam Malik (may Allah have mercy on him) said to me that there is ijtihad (independent judgement) in it.
The Shaykh said: This ruling applies when the wound is so deep that the bone becomes exposed; however, this hadith is munqati' (has a broken chain), and there is no proof in it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16329