Mastoid Obliteration. Histopathologucal Study of Three Temporal Bones

Three temporal bones were serially sectioned to study the postoperative fate of the meatally based postauricular musculoperiosteal flap. In all three ears, the flap sealed off the middle ear effectively from the mastoid cavity and in one, with resected canal wall, formed a new soft posterior wall with good meatus. All flaps contained viable muscle, fat, collagen, reticulin, and elastin, and were richly vascularized. In two flaps, small granulating foci of infection were noted. In two temporal bones, from a child with hypogammaglobulinemia, small cholesterol cysts formed behind the falp during the delayed healing of the mastoid wounds.