Overlay versus underlay tympanoplasty. Comparative study of 122 cases.

INTRODUCTION

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.

CONCLUSION

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.