This thermoplastic device is made to measure from impressions of your teeth. It helps relieve muscle tensions, soothe morning headaches and protect your teeth from long-term wear. Designed to be worn during sleep, the occlusal splint requires a short adjustment period and may cause some irritants such as increased salivation or mild discomfort in the teeth or muscles. Fortunately, these minor annoyances are temporary and disappear as soon as the occlusal splint is removed when you awaken.