Underlay Versus Onlay Myringoplasty and its Outcome : Experience at Tertiary Care Hospitals

INTRODUCTION: The problem of ear drum perforation is almost as old as the human history1, but its incidence in general population is still debatable. Tympanic membrane perforation is mainly caused by acute or chronic suppurative otitis media (ASOM or CSOM) and trauma, either accidental or iatrogenic. Around 70-80% of perforations healed naturally while rest of 20-30% needs surgical repair2. In a survey it was discovered that 4% of native American children had perforated tympanic membrane3. Perforation caused after placing gromets in children having otitis media with effusion is estimated around 3%4. An increased incidence is noted during childhood and in young adults mainly due to higher incidence of CSOM in this group of population5,6. A dry central perforation in a tympanic membrane (TM) chiefly has two effects. One is otorrhea and other is hearing impairment. In such perforations a Myringoplasty operation is usually performed. Two classical techniques have been described as underlay and onlay procedures. Underlay technique is very popular and is widely used as it is relatively simple to perform7. In this the graft is placed medial to the tympanic membrane remanant and malleus. Smaller central perforations are ideal for such technique avoiding the complications of anterior blunting and lateralization, although the reduction in middle ear space and adhesion formation are among its disadvantages. Poor vascular supply to the graft due to limited bed size is also a potential threat for failure2. On the other hand onlay myringoplasty is more challenging and mainly used for total perforations or anterior perforations. Although the rate of success is higher but it takes longer time to heal. However the rate of success by either technique is very much debatable as there are studies with variable results of both procedures in terms of achieving an intact ear drum. This study is carried out to compare the results of underlay and only techniques of myringoplasty in terms of achieving post operative closure of tympanic membrane perforation and improvement in hearing. SUBJECTS & METHOD: This study was conducted in the Departments of E.N.T – Head & Neck Surgery, Liaquat University Hospital Hyderabad and Dow