title: Volume assessment of age-related conversion of the tympanic cavity by helical computerized tomography scanning.
abstract: OBJECTIVE
  To investigate the right-left asymmetry, and gender and age groups differences of the tympanic cavities (TC) using the Cavalieri principle for volume calculation on temporal bone computerized tomography (CT) scans.
  
  
  METHODS
  This study was carried out over a 4-year period from 2000 to 2004 at Firat University, School of Medicine, Elazig, Turkey. The areas of the cavities were measured using trace and area measurement functions of CT scanner, and by multiplying the area by slice thickness (0.2 cm) and the volume of each slice was calculated. By summing all volumes of every slice based on the Cavalieri principle for volume calculation, the total volumes were obtained and analyzed.
  
  
  RESULTS
  The mean (SD) volumes of right and left tympanic cavities in males were 0.52 (0.15) versus 0.55 (0.14) cm3 and in females were 0.45 (0.16) versus 0.49 (0.14) cm3, and there were statistically significant differences between males and females in both right and left sides (p=0.028 and p=0.043). There was a statistically significant difference in left TC volumes between age groups (p=0.019). However, no differences by age were noted for right TC volumes (p=0.065). A strong correlation was found between right and left volumes. However, there were no strong correlations between age and volumes of right and left cavities in both males and females, although the volumes increased by aging.
  
  
  CONCLUSIONS
  These results should help surgeons and radiologists to update their knowledge for evaluation of the middle ear region.
authors.affiliation: Department of Anatomy, School of Medicine, Firat University, Elazig, Turkey. kavaklia@hotmail.com
authors.forename: Ahmet
authors.initials: A
authors.lastname: Kavakli
authors.forename: Murat
authors.initials: M
authors.lastname: Ogeturk
authors.forename: Hanefi
authors.initials: H
authors.lastname: Yildirim
authors.forename: Sacide
authors.initials: S
authors.lastname: Karakas
authors.forename: Turgut
authors.initials: T
authors.lastname: Karlidag
authors.forename: Mustafa
authors.initials: M
authors.lastname: Sarsilmaz
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D015331:Cohort Studies; D004432:Ear, Middle / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012737:Sex Factors; D018709:Statistics, Nonparametric; D036542:Tomography, Spiral Computed / Q000379:methods*