Coal forms from the accumulation of plant debris, usually in a swamp environment. When plant debris dies and falls into the swamp the standing water of the swamp protects it from decay. Swamp waters are usually deficient in oxygen, which would react with the plant debris and cause it to decay.
Porokeratosis is generally considered to be a benign condition though malignant transformation has been seen in all but the punctate variety, necessitating regular followup of patients with porokeratosis (Maubec et al., 2005; Sasson & Krain, 1996).
Torus palatinus is a benign, reactive hyperplasia of osseous tissue extending outward from the surface of the bone. Torus palatinus Osseointegration is defined as the apparent direct attachment or connection of osseous tissue to an inert, alloplastic material without intervening connective tissue [11-14].