Incidence of different causes of benign obstruction of the salivary glands: retrospective analysis of 493 cases using fluoroscopy and digital subtraction sialography.

To identify the incidence of different causes of benign obstruction of the salivary glands, we retrospectively analysed 788 anonymised sialography reports of 719 patients referred to the department of dental and maxillofacial radiology between 2006 and 2012. Reports that showed evidence of benign obstruction were included (n=493). Salivary stones were identified in 151 (31%), ductal strictures in 115 (23%), and mucus plugs in 295 (60%). In 67 cases (14%) there was evidence of 2 or 3 causes of obstruction. As previously reported, mucous plugs were the most common finding, possibly because of the use of fluoroscopy or digital subtraction sialography, or both. These methods enable images to be captured during the initial filling of the main duct and are likely to prevent mucus plugs from being obscured by the contrast medium, which is the case in conventional sialography when a single image is produced after the contrast has been injected.