Associated conditions and clinical significance of awake bruxism.
BACKGROUND
Awake bruxism is defined as an oral parafunctional activity that includes clenching and grinding of teeth during wakefulness. Confirming the possible related anatomy and the clinical significance of awake bruxism in geriatric hospitals is the aim of this study.


METHODS
We analyzed the medical records of 503 patients who were admitted to hospital from April to June 2008. After the recognition of bruxism, the clinical, brain imaging studies and statistical parametric mapping (SPM) of brain single photon emission computed tomography were performed.


RESULTS
In each disease group, five of 125 Alzheimer's disease (AD) patients (4.0%), three of 11 frontotemporal dementia (FTD) patients (27.3%), seven of 230 stroke patients (including two patients related to citalopram, 3.0%), one of 45 Parkinson's disease patients (2.2%) and four of 17 hydrocephalus patients (23.5%) had bruxism. Even though awake bruxism occurred early after stroke onset, it occurred late after AD and FTD onset. This occurred in a far advanced stage of AD, while it occurred in a moderately advanced stage of FTD. SPM analysis in AD and FTD patients with awake bruxism revealed significant hypoperfusion in frontotemporal and other subcortical structures. Surface electromyography recordings from the masseter muscle showed rhythmic regular motor activity at a rate of 1-2/s.


CONCLUSIONS
This study suggests that awake bruxism is encountered not infrequently in various diseases in geriatric hospitals. It is frequently observed in FTD and normal pressure hydrocephalus, which characteristically shows frontal lobe dysfunction. These facts and SPM analysis show that awake bruxism can be regarded as a frontal neurological sign of various neurological disorders.
Kwak
Yong Tae
YT
Department of Neurology, Hyoja Geriatric Hospital, Sanghari 33, Guseong-myeon, Yongin-si Gyeongi-do 449-914, Korea. ytkwak@drkwak.com
Han
Il-Woo
IW
Lee
Phil Hyu
PH
Yoon
Joon-Kee
JK
Suk
Seung-Han
SH
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000453:epidemiology; D002012:Bruxism / Q000150:complications* / Q000453:epidemiology; D003627:Data Interpretation, Statistical; D005260:Female; D057180:Frontotemporal Dementia / Q000150:complications* / Q000453:epidemiology; D006707:Homes for the Aged / Q000706:statistics & numerical data; D006761:Hospitals / Q000706:statistics & numerical data; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000150:complications* / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D020521:Stroke / Q000150:complications / Q000453:epidemiology; D015899:Tomography, Emission-Computed, Single-Photon