Overlay versus underlay tympanoplasty. Comparative study of 122 cases.
BACKGROUND
In tympanoplasty, the most common two techniques for positioning the graft relative to the remnant of both the tympanic membrane and of the annulus, are the "overlay" and the "underlay" techniques. Each technique has advantages and disadvantages.


METHODS
One hundred and twenty-two cases over the age of 8 years who had undergone a tympanoplasty for tympanic membrane perforation secondary to chronic otitis media were included. All patients had a minimum 3-month postoperative otoscopic and audiometric follow-up.


RESULTS
of 122 cases, 115 tympanoplasties (94%) were anatomically successful. At frequencies of 0.5, 1, 2, and 4 kHz, the mean air-bone gap improved significantly from 21.7 dB preoperatively to 8.4 dB postoperatively giving a mean gain of 13.3 dB.


CONCLUSIONS
In our series the underlay or overlay positioning of the graft does not significantly influence the rate of postoperative perforations or complications with the exception of epithelial pearls, which occur significantly more frequently following the overlay technique for perforations that require fibro-epidermal cleaving across a large area.
Gersdorff
M
M
Cliniques Universitaires Saint-Luc, service ORL, Avenue Hippocrate 10, 1200 Bruxelles, Belgique.
Gérard
J M
JM
Thill
M P
MP
D000293:Adolescent; D000328:Adult; D000368:Aged; D001844:Bone Conduction / Q000502:physiology; D002558:Cerebrospinal Fluid Otorrhea / Q000209:etiology; D002648:Child; D005260:Female; D006314:Hearing Loss, Conductive / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010034:Otitis Media with Effusion / Q000150:complications; D011182:Postoperative Care; D011300:Preoperative Care; D012086:Reoperation; D012720:Severity of Illness Index; D013703:Temporal Muscle / Q000637:transplantation; D019737:Transplants; D018058:Tympanic Membrane Perforation / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D014433:Tympanoplasty / Q000295:instrumentation* / Q000379:methods*