(1) The most common form of ossicular chain lesion following head injury is separation of the incudostapedial joint while fractures of the malleus, incus or stapes are described as uncommon.(2) By changes in their development, the articular and the quadrate bones in mammals were modified into two bones, the malleus and incus , whose function was now to transmit sound from the tympanic membrane to the inner ear.(3) Mammals hear sounds after they are transmitted from the outside world to their inner ears by a chain of three bones, the malleus, incus , and stapes.(4) The other possibility is that the piston could have slipped from its position due to the loss of support to it following pressure necrosis of the anchoring bone, namely the incus .(5) The air pressure on either side of the eardrum is normally kept equal for proper functioning of the middle ear structures, namely the malleus, incus and stapes bones.
