Sleep bruxism as the main manifestation of sleep disordered breathing – Case report

Abstract

Sleep related motor activity is often interpreted as part of natural physiological response associated with the complex neurobiological process occurring during sleep. Nevertheless it can be either related with some pathological conditions which are classified in a specific group of sleep disorders – Sleep Related Movement Disorders (ICSD-II). Among the many kinds of motor manifestation during sleep, rhythmic masticatory muscle activity and bruxism may occur in association with sleep disordered breathing. Authors report a case of a female patient with sleep bruxism secondary to undiagnosed sleep disordered breathing in which motor related symptoms where the reason for consultation. None. A female patient, aged 67, obese, come to our clinical unit for a dental appointment, referring, as the main reason for consultation, a widespread symmetrical tooth and face ache, usually felt soon after awakening in the morning. There were no signs of acute, local or systemic disease, no history of smoking or alcohol consumption nor chronic medication except anti-hypertensive one. Sleep disordered breathing was suspected after the initial clinical interview and it was also suspected that motor events could be induced by respiratory events. Sleep related breathing disorder was confirmed by an ambulatory cardio-respiratory sleep study showing an AHI of 18/h and ODI of 18/h. It was also confirmed by masseter activity register the diagnosis of sleep bruxism (MI = 10.6/h). Furthermore it was observed a persistent and regular synchrony between the final part of respiratory events and masseter activity, which was absent after the PAP therapy implementation. As the AHI and ODI improved to normal levels (0.9/h and 0.9/h) confirmed by cardiorrespiratory sleep study, patient came to a follow-up visit showing significant clinical improvement. Neither respiratory nor motor events were observed in this later study. Sleep bruxism can be the first and the main manifestation of sleep disordered breathing. Sleep bruxism related symptoms should therefore be adequately evaluated in a global context that should include sleep history, daytime function and sleep study.