Principles for the management of bruxism

The management of bruxism has been the subject of a large number of studies. A PubMed search, using relevant MeSH terms, yielded a total of 177 papers that were published over the past 40 years. Of these papers, 135 were used for the present review. Apparently, research into bruxism management is sensitive to fashion. Interest in studying the role of occlusal interventions and oral splints in the treatment of bruxism remained more or less constant over the years: between 1966 and 2007, approximately 40-60% of the papers dealt with this subject. The percentage of papers that dealt with behavioural approaches, on the other hand, declined from >60% in the first 2 decades (1966-1986) to only slightly >10% in the most recent decade (1997-2007). In the latter period, >40% of the papers studied the role of various medicines in the treatment of bruxism, while in the preceding decade (1987-1996), only approximately 5% of the studies dealt with the pharmacological management of bruxism. Unfortunately, a vast majority of the 135 papers have a too low level of evidence. Only 13% of the studies used a randomized clinical trial design, and even these trials do not yet provide clinicians with strong, evidence-based recommendations for the treatment of bruxism. Hence, there is a vast need for well-designed studies. Clinicians should be aware of this striking paucity of evidence regarding management of bruxism

Neurobiology of Sleep-Related Movements

Sleep-related movements comprise a broad spectrum of simple and usually stereotyped movements that are sometimes associated with sleep disturbance (insomnia, sleep fragmentation, and non-restorative sleep). They may represent a physiological variant or a sleep disorder, depending on their intensity, frequency, and associated sleep disruption degree. Sleep-related movements involve usually the lower limbs; they can be idiopathic or associated with other sleep disorders, neurological disease, and medical condition or occur as a consequence of drug use. Several pathophysiological hypotheses have been proposed, but for the majority of these disorders, the neurobiological mechanism is far from being completely understood. Further studies are needed to elucidate the pathophysiology of sleep-related movements in order to better appreciate their clinical significance. This chapter describes the neurobiology of sleep-related movements, namely, periodic limb movements, alternating leg muscle activation, hypnagogic foot tremor, high-frequency myoclonus, excessive fragmentary myoclonus, propriospinal myoclonus at sleep onset, neck myoclonus during sleep, sleep bruxism, sleep-related rhythmic movement disorder, sleep-related leg cramps, and sleep starts. We also present a mechanistic model of the potential role of the spinal central pattern generator for locomotion in generating the leg movements