Case Presentation
A 57-year-old man was referred to the Department of Oral and Maxillofacial, Kyoto Medical Center with the chief complaint of recurrent swelling of the right parotid region. Four years before the first visit, he developed bilateral parotid gland swelling and was prescribed antibiotics (cefditoren pivoxil) by his otolaryngologist, and the symptoms disappeared. Three years later, the patient experienced rapid swelling and pain in the right parotid region during sleep when he boarded an airplane and landed. He was prescribed antibiotics in the landed country. The symptoms disappeared gradually and spontaneously, but 3 weeks before the first visit to our department, severe symptoms recurred in the same region, and he visited an otolaryngologist. He took antibiotics (cefditoren pivoxil) for 2 weeks without improvement; he was advised to visit a dentist, following which the dentist introduced him to visit our department.
The right parotid gland of the patient was slightly swollen and tender. He had no fever, and no abnormalities, such as redness, were observed on the skin of the cheek. Blood tests showed no evidence of inflammation. Crepitus was generated by light compression of the right parotid gland, and frothy saliva with fine air bubbles was discharged from the papilla of the right parotid gland (Fig 1). The crepitus and swelling in the parotid region were prominent during waking up. Computed tomography showed air predominantly on the right side of both parotid glands and ducts, and no sialoliths (Fig 2). He was on oral medication because of hypertension. The history of mumps remains unclear. For 20 years from the age of 7 years, he played a traditional Japanese wind instrument, hichiriki (Fig 3). He did not snore. He has gained 4 kg in the last 5 years. His body mass index was 24.1. Since the patient complained of daytime sleepiness, sleep apnea syndrome was suspected. A sleep study was performed on three nights at his home using a pulse oximeter (Pulsox-300, Konica Minolta, Tokyo, Japan). The examination revealed a mean apnea-hypopnea index of 10.3 and a mean minimal oxygen saturation of 81.0%. The patient was diagnosed with mild sleep apnea syndrome. The minimal oxygen saturation was considerably reduced.
It was postulated that desaturation events could be related to a rapid increase in intraoral pressure. Therefore, an oral appliance to prevent obstruction of the upper airway and reduce intraoral pressure (Fig 4) was fabricated as described previously.29-31 The mandibular position was 6 mm, protruding from the intercuspal position. An anterior opening was made between the upper and lower incisors (Fig 4). After insertion of the oral appliance, the sleep variables improved considerably (mean apnea-hypopnea index, 2.9; mean minimal oxygen saturation, 90.8%). One month later, the symptoms of pneumoparotid disappeared completely. The patient was followed up with the appliance. After a few years, the patient discontinued the appliance as the symptoms disappeared. After 4 years, the patient had bilateral parotid gland swelling, and antibiotics were prescribed for 1 week by an otolaryngologist. After 9 years, the patient had tenderness and swelling of the left parotid gland. He revisited our department for re-examination. The left parotid gland was tender. No abnormalities were observed on the skin of the parotid region. Blood tests showed no evidence of inflammation. Crepitus was detected by compression of the left parotid gland, and frothy saliva with fine air bubbles was discharged from the papilla of the left parotid gland. Computed tomography showed the presence of air in both ductal systems, with more prominent findings in the left parotid gland (Fig 2B). A sleep study was conducted again. The test revealed a mean apnea-hypopnea index of 10.1 and mean minimal oxygen saturation of 79.8%. The results were remarkably similar to those 9 years ago. Oral appliance was inserted again, and sleep variables improved (mean apnea-hypopnea index: 3.1, mean minimal oxygen saturation: 90.3%). The symptoms related to sleep apnea syndrome and pneumoparotid disappeared completely. The patient was followed up for 10 years from the first visit. Relapse of the entities has not been observed until now.