To determine whether epithelial migration in the atelectatic tympanic membrane (secondary to any pathology) occurs in a similar fashion to that in the normal (non-pathological) tympanic membrane, by calculating and comparing the epithelial migration rate and pattern.

Prospective, non-randomised, case–control study. This study was a pilot study. We included patients with an atelectatic pars tensa region of the tympanic membrane and a healthy contralateral tympanic membrane (the latter used as the control).

Otorhinolaryngology out-patient clinic. The study was conducted from January 2006 to January 2008.

A total of 40 patients (80 ears) were included based on their otoscopic appearance and tympanography findings. All patients' ears were examined under an operating microscope. A dot of methylene blue dye was applied in the immediate vicinity of the umbo of the atelectatic tympanic membrane, and in the same position on the tympanic membrane of the control ear. Patients were then followed up weekly until the dye dot had migrated to reach the annulus.

Direction and rate of epithelial migration.

In the atelectatic tympanic membranes, epithelial migration proceeded from the centre of the retraction pocket toward the annulus in a lateral, radiating manner. Thirty-three (82.5 per cent) of the 40 patients showed a similar migratory pattern in both the study and control ears. Sixty per cent of the retracted tympanic membranes showed no migration in the first week after methylene blue staining. After the first week, the migration rate was nearly constant from the umbo towards the periphery, in both the study and control ears. The mean daily epithelial migration rate in the study and control ears was 62.6 and 64.7 µm/day, respectively; however, this difference was statistically insignificant (p = 0.202, independent samples t-test).

There is no difference in the epithelial migration rate or pattern, comparing atelectatic tympanic membranes and normal tympanic membranes. However, there may be a significant difference in the epithelial migration rate with increased grades of tympanic membrane atelectasis.