Tympanic membrane perforation: size, site and hearing evaluation.
OBJECTIVE
To assess different clinical scales of TM perforation size; to evaluate the effect of the size and the site of a perforation on the hearing level and frequencies.


METHODS
Prospective study. Observers had subjectively estimated the size in millimeter and in percentage of a particular perforation; objectively computerized measures of TM perforations area were analyzed. Agreement between different measures was studied. Cases with postoperative intact TM and an air-bone gap (ABG) of 10 dB or less were studied.


RESULTS
Global mean preoperative ABG was 21.8 ± 17 dB. Preoperative ABG was different between small-large and small-total perforations (p=0.001). Difference of the preoperative ABG was statistically significant between perforations filling up the four quadrants and perforation limited to one quadrant in the postero-inferior, antero-superior and antero-inferior site. No statistically difference between perforation sites was identified for each affected frequency. Difference is statistically significant (p=0.001) between the 250 Hz and the other frequencies for the medium, large and total perforations. After myringoplasty bone conduction improvement was statistically significant for the frequencies 500 (p=0.04), 1000 (p=0.04) and 2000 Hz (p=0.011). Agreement was large enough when TM perforation size was expressed in percentage and absent when expressed in millimeter.


CONCLUSIONS
TM perforation can be clinically estimated quite precisely as a percentage of the TM area. Conductive hearing loss is frequency dependent; with the greatest loss occurring at the lowest sound frequencies. Hearing loss does not depend on the perforation's location.
Sainte-Justine University Hospital Center (CHU SJ), 3175, Côte Sainte-Catherine, Department of Otorhinolaryngology, Montreal, QC, H3T 1C5, Canada. issam.saliba@umontreal.ca
Issam
I
Saliba
Anthony
A
Abela
Pierre
P
Arcand
D001301:Audiometry, Pure-Tone / Q000379:methods*; D001309:Auditory Threshold / Q000502:physiology; D001844:Bone Conduction / Q000502:physiology*; D016009:Chi-Square Distribution; D015331:Cohort Studies; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006314:Hearing Loss, Conductive / Q000175:diagnosis; D006320:Hearing Tests / Q000379:methods; D006801:Humans; D008297:Male; D009225:Myringoplasty / Q000379:methods*; D015588:Observer Variation; D011182:Postoperative Care / Q000379:methods; D011446:Prospective Studies; D012720:Severity of Illness Index; D012984:Software; D016896:Treatment Outcome; D018058:Tympanic Membrane Perforation / Q000175:diagnosis* / Q000601:surgery