Sleep apnea and obstructive sleep disorders represent a danger for the cardiovascular system and metabolism. They also give rise to somnolence, which can cause accidents at work or road accidents. Along with positive pressure ventilation, oral mandibular advancement devices are today regarded as reliable forms of treatment. Unfortunately, not all patients adhere fully to the treatment, particularly over time. Some even abandon it entirely. The reasons generally put forward to explain this poor compliance are discomfort, pain, occlusal problems and poor psychological disposition (Figure 1). Orthesis over three years showing the high levels during the first months of treatment.