ObjectiveMeasure the volume of air-containing space in children with cleft palate and assess age-related changes, recurrence rate of otitis media with effusion (OME) after tube removal, and temporal bone development trend based on time of tube placement.DesignInterventional prospective study.SettingCleft Lip and Palate Center at a Tertiary-level institution.Patients/ParticipantsOne hundred sixty-eight ears of 86 patients who visited our center from January 2018 to December 2019.InterventionsWe performed tympanometry (impedance audiometry) after tube placement.Main Outcome MeasuresRecurrence (at least one episode of OME after tympanic membrane closure), tympanic cavity volumes, and timing of tube placement.ResultsThe mean air-containing cavity volume was 1.62 mL, 2.99 mL, and 3.29 mL in patients aged 1, 2, and 3 years, respectively. A rapid increase in volume was observed around 2 years of age. Twenty-two (42.3%) of the 52 ears with pneumatic cavity volumes <
3 mL, and four (14.3%) of the 28 ears with pneumatic cavity volumes ≥3 mL had recurrence. Tubes were placed at ages <
1 year and ≥1 year in 28 and 62 ears, respectively. The pneumatic cavity volume tended to be greater in the ears with tube placement at age <
1 year.ConclusionThis study provided insights into using pneumatic cavity volume measurements to determine the appropriate timing for tube removal. Tubes should be placed as early as possible (before the age of 2 years) for prolonged OME associated with children with cleft palate.