DEVELOPMENTAL ANATOMY OF THE SUPRATUBAL RECESS IN TEMPORAL BONES FROMFETUSES AND CHILDREN

The supratubal recess (STR), located superior to the bony eustachian t ube and anterior to the attic and often the site of disease, is clearl y separated from the attic by the presence of a bony partition. Its an atomic development in childhood, however, remains unclear. We reviewed serial horizontal sections of fetal and children's temporal bones fro m the collection of the Otopathology Laboratory, University of Minneso ta. Apparently, upward expansion of the bony eustachian tube begins at a late fetal stage and continues throughout childhood thus forming th e STR. Our finding that the STR had already developed in temporal bone s without pneumatization of petrous bone suggests that its formation i s independent of the air-cell system. Absorption of mesenchymal tissue in the STR tends to be slower than elsewhere in the temporal bone. Su rrounded solely by petrous bone, the STR seems, both developmentally a nd anatomically, a distinctive compartment of the middle ear.