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The Superior Petrosal Triangle as a Constant Anatomical Landmark for Subtemporal Middle Fossa Orientation
Author(s) -
Miller Robert Sean,
Pensak Myles L.
Publication year - 2003
Publication title -
the laryngoscope
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.181
H-Index - 148
eISSN - 1531-4995
pISSN - 0023-852X
DOI - 10.1097/00005537-200308000-00012
Subject(s) - anatomy , cadaveric spasm , malleus , middle cranial fossa , cadaver , medicine , temporal bone , middle ear , stapes
Objectives/Hypothesis Anatomical landmarks including the arcuate eminence and the superficial petrosal nerve serve as orienting landmarks for middle fossa dissection. However, because of considerable variation among patients, these landmarks are not always readily identifiable. We expand on a previously described method for identifying the head of the malleus as a constant anatomical landmark to optimize exposure when employing a middle fossa approach. Methods We completed an anatomical study using 10 preserved human cadaveric temporal bones to define the anatomical relationship among the root of the zygoma, the posterior–lateral lip of the foramen spinosum, and the bony tegmen over the head of the malleus. Subsequently, 5 fresh whole human cadaveric heads (10 temporal bones) were dissected using a surgically oriented anterior petrosectomy–middle fossa approach to evaluate the consistency of localizing the head of the malleus. Results We defined the superior petrosal triangle as a stable anatomical relationship. Our cadaveric data demonstrated that the distance from the root of the zygoma to the head of the malleus was 18.7 mm (SD = 1.7 mm) and the distance from the foramen spinosum to the head of the malleus was 19.2 mm (SD = 1.0 mm). The intersection of an arc transcribed 19 mm from the root of the zygoma and an arc transcribed 19 mm from the foramen spinosum localized the head of the malleus within 2.5 mm (SD = 2.4 mm). Conclusions The landmarks defined by the superior petrosal triangle represent a means to localize the bony tegmen over the head of the malleus. Identification of the head of the malleus as a landmark in middle fossa surgery when other landmarks are not recognizable optimizes patient safety and surgeon confidence during complex surgical procedures.