Bruxism Bruxism is a parafunctional activity which involves the clenching and grinding of teeth. This can occur consciously when awake (awake bruxism) or at night when asleep (sleep bruxism). Awake bruxing is more common in females, has been linked to anxiety and stress, and is thought to affect 20% of the population. The prevalence of sleep bruxism decreases with age, with it being reported in 14–18% of children, 8% of adults and only 3% of elderly. Sleep bruxism is frequently noisy and reported by partners, and individuals may wake up with stiffness and aching of the jaws. Complaints of headaches are also common. Occlusal interferences were once thought to provoke sleep bruxism, but it is now thought of as a sleep-related movement disorder. Most bruxism is mild and non-damaging to tooth tissue; as such, no treatment is required. However, for some, tooth wear and fracture may occur or the noise of grinding is unacceptable for partners and treatment is sought. For these patients a correctly adjusted hard acrylic splint can be supplied for night-time or daytime wear to protect the teeth. Such splints are referred to as stabilization splints and can be worn in the maxillary (Michigan splint, Figure 6.1) or mandibular arch. Figure 6.1. A Michigan splint being fitted and occlusion being checked to ensure all lower teeth occlude with the splint (A, B). Manufacture using casts mounted on an articulator reduce the amount of adjustment. The splint should have a canine rise in lateral excursions (C, D). An alternative splint is the localized occlusal interference splint (LOIS appliance, Figure 6.2). This consists of an acrylic plate retained by suitable clasps and two ball-ended wires which are placed between opposing teeth to interfere with the occlusion. Occlusal loading of the ball interferences leads to stimulation of periodontal mechanoreceptors, afferent feedback and reduction in occlusal loading. When used for bruxing habits, both splints act as a ‘habit breaker’ and patients can be gradually weaned off them. Figure 6.2. Localized occlusal interference splint (LOIS appliance). The ball-ended wires on the occlusal surface of the canine–premolar teeth interfere with the occlusion and are aimed at breaking a bruxism habit. (Courtesy of Dr John Radford) If tooth destruction has taken place as a result of bruxism and restorative management is required, damage to any restorations can occur and it is important that the patient is aware of this. Damage to new restorations can be reduced by correct choice of dental materials, namely metal occlusal surfaces where possible and protection of restorations with a stabilization splint which can be worn at night for sleep bruxism and during the day if necessary for awake bruxism.
