This study aims to verify the efficacy of adjuvant adenoidectomy for children with chronic OME who become candidates for tympanostomy tube placement, and explore potential factors associated with the efficacy of adjuvant adenoidectomy.

Otitis media with effusion is a common condition in children, and tympanostomy tube placement is the first-line treatment for those who requires surgical interventions. Adenoidectomy proves to be helpful to children over 4 years old, but the risks of adjuvant surgery is believed to somehow offset its benefits. This study is meant to verify if concurrent adenoidectomy provides extra benefits in resolving MEE, reducing AOM, and improving hearing and patients' quality of life to children who become candidates for TT.

Inclusion Criteria:

• 1. Children 4-12 years of age.
• 2. Diagnosed with chronic OME. Diagnostic criteria: I. Middle ear effusion detected by otoscopy; II. Type B or C tympanograms; III. Symptoms/signs of OME persisted for >3 months;
• 3. Documented hearing loss ≥20dB (average threshold of 500Hz, 1000Hz and 2kHz in pure tone audiometry).
• 4. Adenoid hypertrophy (A/N ratio> 0.5 in lateral radiography of the nasopharynx).
• 5. Informed consent given by the patients and their guardians.

Exclusion Criteria:

1. Cleft palate or other systemic disorders.
2. Patients are diagnosed with other nose, sinuses or ear diseases that are eligible for surgical treatment.
3. Patients are diagnosed with OSAHS, tonsil hypertrophy ≥II° or scheduled for tonsillectomy.
4. History of tympanostomy tube placement.
5. Infection of the upper respiratory tract or acute rhinosinusitis over the past 7 days.
6. Sensorineural hearing loss.
7. Other situations that the investigators find unsuitable for the trial.