The purpose of this study was to assess the effectiveness of sialendoscopy (SE) on the symptom severity of chronic obstructive sialadenitis (COS) and patient satisfaction by using the Chronic Obstructive Sialadenitis Symptoms (COSS) questionnaire and the Patient Satisfaction Scores (PSS).

COSS questionnaire was employed to 51 Turkish patients with COS before and three months after SE. Patients’ satisfaction with SE was evaluated by analyzing the PSS.

Gland preservation rate of the SE operation was 96.2%. The sialolith extraction rate was 74.2%. A significant decrease in the COSS scores of all of the patients in the study sub-groups was observed (p < 0.05). The effectiveness of SE was more pronounced for patients with sialolithiasis and submandibular gland (SG) involvement (p < 0.001, p = 0.03, respectively). Totally extracted stone and symptom duration were the only independent factors that significantly affected the COSS score gain values in patients with and without sialolithiasis, respectively (p < 0.001). There was a statistically significant correlation between COSS score gain values and PSS values. (r = 0.786)

The benefit of SE was more pronounced in patients with sialolithiasis and SG involvement. Successful stone extraction and symptom duration were two independent factors that influenced both clinical improvement and patient satisfaction for patients with and without sialolithiasis, respectively. COSS questionnaire results correlated with the PSS values; thus, this questionnaire can also be used to evaluate the patients’ satisfaction with SE.