An air delivery device (ADD) for applying fluid pressure pulses (FPP) to the mouth cavity of a patient at a predetermined frequency according to a protocol The ADD, comprises: a) an air blower for blowing air into a pressure chamber via a first opening (inlet); b) airflow occluding means (AOM) provided in fluid communication with said pressure chamber; said AOM located between said first opening and a second opening (outlet) of said pressure chamber; c) a patient mouthpiece or Face Mask, in fluid communication with said second opening (outlet); and, d) means for controlling AOM, adapted to interrupt and release said airflow at a predetermined frequency and pressure, thereby applying said FPPs to the mouth cavity of a patient according to a predetermined protocol during operation.