The ponticulus: an anatomic study.

Department of Otolaryngology-Head & Neck Surgery, Marshfield Clinic, Marshfield, Wisconsin 54449, USA. holt.james@marshfieldclinic.org

HYPOTHESIS: The purpose of this study was to resolve anatomic ambiguities of the ponticulus so the surgeon will be better able to remove disease from the posterior tympanum. BACKGROUND: The first step in refining an operative approach is to acquire a thorough understanding of the anatomy. A detailed study of one structure of the posterior tympanum, the ponticulus, has not yet been reported. METHODS: Fifty temporal bone plugs harvested from human cadavers were studied. The presence or absence of the ponticulus, its configuration, and its proximity to other middle ear structures were recorded for each temporal bone. RESULTS: There was complete formation of the ponticulus in 33 of the 50 specimens. In 7, only a remnant of the ponticulus formed, and it was completely absent in 10 of the 50 specimens. In the 33 specimens in which the ponticulus was present, it measured less than 1 mm in thickness in 22, it was larger than 1 mm in 7, and in 4 specimens it extended down to the floor of the middle ear as a sheet of bone. In 8 specimens, the ponticulus lay just adjacent to the stapes. CONCLUSION: The ponticulus is present in the majority of ears. It is best defined as a bridge of bone from the pyramidal eminence to the promontory and most commonly occurs as a thin, bony structure. This definitive study of the ponticulus will allow the otologic surgeon to better remove disease from the posterior tympanum.

PMID: 16272927 [PubMed - indexed for MEDLINE]