BACKGROUND : A new approach to treat obstructive sleep apnea (OSA) is upper airway stimulation therapy (UAS). Electrical pulses applied to the hypoglossal nerve induce tongue protrusion, increase airway patency and decrease the frequency of apneic and hypopneic events. Thus, the main objective of this study was to design a standardized evaluation of endobuccal adverse events induced by repeated tongue protrusion with both a dedicated questionnaire and an endobuccal examination. METHODS : This study has designed the Tongue Adverse Event and Satisfaction Questionnaire (TAESQ) and an endobuccal examinations divided into an endobuccal lesion examination (ELE) and an endobuccal risk factor examination (ERFE). Evaluations were conducted at month 6 post-implantation. RESULTS : The study population after implantation of UAS device consisted of ten Caucasian males with a mean age of 51.9 ± 11.8 years, and a mean BMI of 28.6 ± 3.3. The AHI of the ten participants ranged from 46.7 ± 12.2/h at baseline to 14.5 ± 8.9/h with the Inspire therapy at the 6-month follow-up. The TAESQ revealed pain (30%), followed by less tongue sensitivity (20%) and tongue weakness (10%). The ELE did not reveal any lesions. The ERFE revealed that some participants had tissue and dental risk factors but not associated to more adverse events. CONCLUSIONS : The TAESQ, ELE and ERFE have been designed and studied on a small number of participants. These evaluations could systematically be included in the care pathway of patients treated by UAS to better investigate tongue discomfort and tongue lesion for patients treated with this technology.