Hypothesis: The aim of this study was to find suitable methods for basic anatomic evaluation of the supratubal recess and the anterior surface of the tensor fold.
Background: The current method of superior microdissection via the middle fossa floor provides a good picture of the anatomy and pathology of the epitympanum, but the supratubal recess can be evaluated only after excision of the tensor fold. Postinflammation changes cannot be examined accurately because destruction of the tensor fold necessarily alters the anatomic details.
Methods: Eight temporal bones were studied via a lateral and 14 via an anterior approach, both complemented by the superior microdissection. Data on 51 earlier superior dissections were reevaluated as to the state of the supratubal recess. Histology was documented from eight biopsy specimens and of four serially sectioned temporal bones, two normal and two infected.
Results: The lateral route offered a good view to the tensor tendon and lower portion of the tensor fold, but the anterior malleal ligament obstructed the view to the fold's upper portion. The anterior route offered excellent visibility to the anterior pouch, mesotympanum, tensor fold, and the whole supratubal recess. The tensor fold was mostly fixed superiorly to the bony roof with a narrow or broad soft band of composite tissue, infrequently to the transverse crest directly. Inflammatory changes spread from the tympanic isthmus region to the supratubal space over the fold and, if extensive, formed broad inflammatory and scar tissue bands between the fold and the anterior bony wall.
Conclusions: The supratubal recess and the mesotympanum can best be evaluated via the anterior approach, which should be added to the temporal bone microdissection program. It serves well as the starting route, followed by the conventional superior dissection of the epitympanum. The knowledge gained is indispensable in surgery for chronic otitis media for creation of a large common middle ear air space and functioning aeration pathways.