What a compelling description of repellent dentistry. Twice Flay is described so, the second time being further likened to the prehistoric beauty of a turtle. In both cases, he is contemplating Swelter, the cook with whom he is locked into mutual, mortal enmity. 

‘As it was he bared his sand-coloured teeth, and fixed his eyes for a last moment on the cook with an expression of unbelievable menace.’ 

‘… and he jerks his dark, sour, osseous head forward out of his collar like a turtle and hisses from between his sand-coloured teeth.’  

Source: Mervyn Peake, Titus Groan, introduction by Anthony Burgess (London: Vintage Books, 1998), p. 29 and 342