Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-26T15:00:00.810Z Has data issue: false hasContentIssue false

Correlation between retractions of the pars flaccida and the pars tensa

Published online by Cambridge University Press:  29 June 2007

Michal Luntz*
Affiliation:
Hearing Research Laboratory, Sackler School of Medicine and the Biomedical Engineering Department, University of Tel-Aviv, Ramat Aviv, Tel-Aviv, Israel.
Camil Fuchs
Affiliation:
The Department of Statistics and Operation Research, Raymond and Beverly Sackler, Faculty of Exact Sciences, University of Tel-Aviv, Ramat Aviv, Tel-Aviv, Israel.
Jacob Sadé
Affiliation:
The Sara and Felix Diamond Professonal Department for Hearing Disorders, University of Tel-Aviv, Ramat Aviv, Tel-Aviv, Israel.
*
Address for correspondence: Michal Luntz, M.D., Hearing Research Laboratory, The Biomedical Engineering Department, POB 39040, Tel-Aviv University, Ramat-Aviv, Tel-Aviv, Israel, 69978.

Abstract

Retractions of the pars flaccida (PF) and the pars tensa (PT) were assessed in 250 atelectatic ears in an attempt to find out the way in which the differences in mechanical properties of the two parts of the tympanic membrane are reflected clinically. Retraction of PF was found in 217 ears (86.8 per cent) and retraction of PF in 150 (60 per cent). The concomitant presence of both types of retraction was observed in 117 ears (46.8 per cent) while 133 (53.2 per cent) had only one type, 100 of them (75.1 per cent) PF retraction and 33 (24.9 per cent) PT retraction. When only one type of retraction was present, the empirical probability of having a PF retraction was 75.1 per cent, while the probability of having a PT retraction was only 24.9 per cent. Clinically, the more frequent occurrence of PF retraction in the absence of PT retraction than vice versa reflects the greater collapsibility of the PF. When both types of retractions were present, we found a positive correlation between their severity.

Type
Main Articles
Copyright
Copyright © JLO (1984) Limited 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Buckingham, R.A., Ferrer, J. L. (1973) Middle ear pressure in a Eustachian tube malfunction, manometric studies. Laryngoscope 83: 15851593.CrossRefGoogle Scholar
Beer, F. B., Johnston, E. R. (1976) Mechanics for Engineers, Statics and Dynamics. 3rd Edition. McGraw-Hill, New York, pp 236237.Google Scholar
Bekesy, G. (1960) Experiments in Hearing. McGraw-Hill, New York, pp 101103.Google Scholar
Hellstorm, S., Stenfors, L. E. (1983) The pressure equilibrating function of pars flaccida in the middle ear mechanics. Acta Physiologica Scandinavia 118: 337341.CrossRefGoogle Scholar
Hentzer, E. (1989) Ultrastructure of the human tympanic membrane. Acta Otolaryngologica (Stockholm) 68: 376390.CrossRefGoogle Scholar
Lim, D. (1968a) Tympanic membrane, electron microscopic observation. I. Pars tensa. Acta Otolaryngologica (Stockholm) 66: 181198.CrossRefGoogle ScholarPubMed
Lim, D. (1968b) Tympanic membrane. II. Pars flaccida. Acta Otolaryngologica (Stockholm) 66: 515531.CrossRefGoogle ScholarPubMed
Sadé, J. (1993) Atelectatic tympanic membrane: histologic study. Annals of Otology, Rhinology and Laryngology 102: 712716.CrossRefGoogle ScholarPubMed
Sadé, J., Avraham, S., Brown, M. (1981) Atelectasis, retraction pockets and cholesteatoma. Acta Otolaryngologica 92: 501512.CrossRefGoogle ScholarPubMed
Sadé, J., Berco, E. (1976) Atelectasis and secretory otitis media. Annals of Otology, Rhinology and Laryngology 85 (suppl. 25): 6672.CrossRefGoogle ScholarPubMed
Sadé, J., Halevi, A., Hadas, E. (1976) Clearance of middle ear effusions and middle ear pressures. Annals of Otology, Rhinology and Laryngology 85: 5862.CrossRefGoogle ScholarPubMed
Shrapnell, H. J. (1832) On the form and structure of the membrana tympani. London Medical Gazette 10: 120124.Google Scholar
Stenfors, L. E., Salen, B., Winblad, B. (1979) The role of the pars flaccida in the mechanics of the middle ear. Acta Otolaryngologica 88: 395400.CrossRefGoogle ScholarPubMed
Widemar, L., Hellstrom, S., Stenfors, L. E. (1986) Different structural changes in membrana shrapnelli in serous and purulent otitis media. Acta Otolaryngologica (Stockholm) 102: 266273.CrossRefGoogle ScholarPubMed