Comparison of cochlear duct length between the Saudi and non-Saudi populations

BACKGROUND: There are no data on cochlear duct lengths (CDL) among Middle East populations. OBJECTIVES: The main aims of this study were to estimate the average CDL in the Saudi population and to compare it with the reported CDL in other regions/ethnic groups outside the Middle East. DESIGN: Retrospective study. SETTING: Tertiary otolaryngology head and neck surgery center. SUBJECTS AND METHODS: Temporal bone CT scans were reviewed to determine CDL. We excluded any CT scan of an ear with a congenital inner ear anomaly or acquired pathology. MAIN OUTCOME MEASURES: CDL. SAMPLE SIZE: 441 temporal bone CT scans. RESULTS: The overall CDL mean was 31.9 mm (range 20.3–37.7 mm). The cochleae of males was significantly longer than of females and cochleae from the left side were significantly longer than of the right side. No significant difference was found between children and adults. Inter-study comparison revealed a significant difference in CDL between the Saudi population in our study and European and Australian studies, but not between the present study and North American studies. CONCLUSIONS: The CDL differed significantly according to side of the cochlea and sex, but not by age. Geographically and ethnically, the mean CDL for Saudis was significantly different from the CDL of subjects of some ethnic backgrounds, but not others. Due to this diversity, we recommend that the CDL be measured before cochlear implant surgery. LIMITATIONS: All the measurements were done by one person, and the subjects’ physical measurements, such as height or head circumference, were not included.