Subcutaneous emphysema are rare complications in periodontology. In most cases, they resolve spontaneously. However, air might disperse into deeper facial spaces causing life-threatening complications such as compression of the tracheobronchial tree or the development of pneumomediastinum. Moreover, microorganisms might spread from the oral cavity into deeper spaces. Hence, rapid diagnosis of subcutaneous emphysema is important. Characteristic signs are both a shiftable swelling and a crepitation. In this case report, the case of a 69-year old man with a subcutaneous emphysema immediately after peri-implantitis therapy with the use of a glycine-based powder air-polishing device is described. Following therapy, air accumulated in the left side of the face. Seven days after non-surgical peri-implantitis therapy, the patient was asymptomatic with complete resolution of the emphysema.