Table 1.

Definitions of dental sleep disorders as distinguished by Lobbezoo et al13

Condition	Definition
Oro‐facial pain (OFP)	Oro‐facial pain refers to pain associated with the hard and soft tissues of the head, face and neck. These tissues, whether skin, blood vessels, teeth, glands or muscles, send impulses through the trigeminal nerve to be interpreted as pain by the brain circuits that are primarily responsible for the processing that controls complex behaviour. The complaint of OFP encompasses a diagnostic range from neurogenic, musculoskeletal, and psychophysiological pathology to headaches, cancer, autoimmune phenomenon, and tissue trauma (de Leeuw & Klasser16)
Oral moistening disorders	Oral moistening disorders can be divided in having too little or too much saliva, respectively, yielding oral dryness and oral wetness Hyposalivation is an objective reduction of the salivary flow; salivary gland hypofunction has been defined as any objectively demonstrable reduction in whole and/or individual gland flow rates Xerostomia is defined as the subjective sensation of oral dryness; although it is most commonly associated with salivary gland dysfunction, it may also occur with normal gland activity. The terms hyposalivation and xerostomia are often incorrectly used interchangeably Hypersalivation (or sialorrhea or ptyalism) is the condition of increased salivary flow (Lobbezoo et al13; Wolff et al25; Löfgren et al27; Moore & Guggenheimer78; Hopcraft & Tan26; Boyce & Bakheet79)
Gastroesophageal reflux disease (GERD)	Gastroesophageal reflux disease is defined, in the so‐called Montreal definition and classification, as a condition that develops when the reflux of stomach contents causes troublesome symptoms and/or complications The disease was subclassified into esophageal and extra‐esophageal syndromes, and the recognition of laryngitis, cough, asthma, and chemical intrinsic tooth wear as possible GERD syndromes (Vakil et al80)
Sleep‐related breathing disorders	Sleep‐related breathing disorders include snoring and obstructive sleep apnoea syndrome (OSAS) Snoring is a familiar condition that is characterised by loud breathing sounds produced in the upper airway during sleep; loud snoring is considered as the most important alarm symptom for OSAS OSAS is the most common type of sleep apnoea and is caused by obstruction of the upper airway. It is characterised by repetitive pauses in breathing during sleep, despite the effort to breathe, and is usually associated with a reduction in blood oxygen saturation (Deary et al46; American Academy of Sleep Medicine Task Force, Sleep45)
Mandibular movement disorders	Mandibular movement disorders include oromandibular dystonias, oro‐facial dyskinesias, sleep bruxism, and awake bruxism Sleep bruxism is a masticatory muscle activity during sleep that is characterised as rhythmic (phasic) or non‐rhythmic (tonic) and is not a movement disorder or a sleep disorder in otherwise healthy individuals Awake bruxism is a masticatory muscle activity during wakefulness that is characterised by repetitive or sustained tooth contact and/or by bracing or thrusting of the mandible and is not a movement disorder in otherwise healthy individuals (Lobbezoo et al56)