Phasic jaw motor episodes in healthy subjects with or without clinical signs and symptoms of sleep bruxism: a pilot study

• Published in: Sleep & breathing 2014-03, Vol.18 (1), p.187-193
• Main Authors: Yoshizawa, Shuichiro, Suganuma, Takeshi, Takaba, Masayuki, Ono, Yasuhiro, Sakai, Takuro, Yoshizawa, Ayako, Kawana, Fusae, Kato, Takafumi, Baba, Kazuyoshi
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Child clinical studies; Dentistry; Developmental disorders; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Electromyography; Female; Fundamental and applied biological sciences. Psychology; Humans; Hypertrophy; Infantile autism; Internal Medicine; Jaw - physiopathology; Male; Masseter Muscle - pathology; Masseter Muscle - physiopathology; Masticatory Muscles - physiopathology; Medical sciences; Medicine; Medicine & Public Health; Movement; Nervous system (semeiology, syndromes); Neurology; Original Article; Otorhinolaryngology; Pediatrics; Pneumology/Respiratory System; Polysomnography; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Sleep Bruxism - diagnosis; Sleep Bruxism - physiopathology; Sleep disorders; Sleep. Vigilance; Tooth Attrition - diagnosis; Tooth Attrition - physiopathology; Vertebrates: nervous system and sense organs
• ISSN: 1520-9512; 1522-1709
• DOI: 10.1007/s11325-013-0868-6

Background To investigate the association between each clinical diagnosis criterion for sleep bruxism (SB) and the frequency of jaw motor events during sleep. Methods Video-polysomnography was performed on 17 healthy adult subjects (mean age, 26.7 ± 2.8 years), with at least one of the following clinical signs and symptoms of SB: (1) a report of frequent tooth grinding, (2) tooth attrition with dentine exposure through at least three occlusal surfaces, (3) morning masticatory muscle symptoms, and (4) masseter muscle hypertrophy. Episodes of rhythmic masticatory muscle activity (RMMA) and isolated tonic activity were scored visually. These variables were compared with regards to the presence or absence of each clinical sign and symptom. Results In 17 subjects, 4.0 ± 2.5/h (0.1–10.2) RMMA and 1.0 ± 0.8/h (0–2.4) isolated tonic episodes were observed (total episodes: 5.0 ± 2.4/h (1.2–11.6)). Subjects with self-reported grinding sounds ( n  = 7) exhibited significantly higher numbers of RMMA episodes (5.7 ± 2.3/h) than those without ( n  = 10; 2.8 ± 1.8/h) ( p  = 0.011). Similarly, subjects with tooth attrition ( n  = 6) showed significantly higher number of RMMA episodes (5.6 ± 3.1/h) than those without ( n  = 11; 3.2 ± 1.6/h) ( p  = 0.049). The occurrence of RMMA did not differ between the presence and absence of morning masticatory muscle symptoms or muscle hypertrophy. Conclusions Clinical signs and symptoms frequently used for diagnosing SB can represent different clinical and physiological aspects of jaw motor activity during sleep.