Drug-induced sleep endoscopy (DISE), performed in the operating room, improves airway obstruction phenotyping in obstructive sleep apnea syndrome (OSAS). It pharmacologically approximates human sleep and allows dynamic maneuvers, notably including mandibular advancement, the results of which are predictive of those with a mandibular advancement device (MAD): when obstruction is resolved by mandibular advancement under DISE, a MAD may be indicated. However, individual maximal mandibular advancement in the waking state has to be taken into account, and the MAD should not exceed 75% of this value (MA75), in order to respect temporomandibular joint tolerance. Thus, MA75 needs to be measured and reproduced exactly during DISE in order to assess the clinical indication for MAD in terms of both efficacy and tolerance. The present technical note describes a method for measuring MA75 and reproducing it during DISE with an adapted device so as to select candidates for MAD.