CLINICAL IMPORTANCE OF THE KORNERS SEPTUM

Objective: To evaluate the clinical importance of the petrosquamosal l amina (Korner's septum [KS]), which is not only a bony plate dividing the mastoid cells at the level of antrum, but is also a lamina startin g from the posterior aspect of the glenoid fossa that extends above th e middle ear cavity and courses in an inferior direction lateral to th e facial canal and proceeds to the mastoid apex. Study Design and Sett ing: A retrospective review of 688 mastoidectomies performed in Univer sity Hospital from 1987 to 1992, Patients: The study group consisted o f 389 males and 299 females (mean age 30.85 +/- 12.80, the youngest be ing 8 and the oldest being 67 years of age). Main Outcome Measures: Th e main outcome measures were the prevalence of KS encountered during m astoidectomies and comparison of prevalence of retraction pockets (RPs ) or retraction and/or adhesion of the whole tympanic membrane (R/A-TM ) between ears with KS and without KS, Results: The prevalence of KS w as 30.4% among the ears with RP or R/A-TM, 6.58% in normal ears, and 1 7.4% in ears with chronic otitis media without RP or R/A-TM. Conclusio ns: KS is an important anatomic handicap predisposing the individual t o chronic otitis media, particularly when it is characterized by attic retraction pockets and cholesteatoma, and adhesive otitis media, beca use KS contributes to attic blockage. This statement is in accordance with the original articles written by Cheatle (1910, 1923) and William s (1966), and recently published data related to supratubal recess and the cog (Tono et al., 1996).