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Is self‐reported jaw pain on mouth opening associated with a reduced bruxism time index?
Author(s) -
VAN DER ZAAG J.,
LOBBEZOO F.,
WICKS D.J.,
HAMBURGER H.L.,
NAEIJE M.
Publication year - 2002
Publication title -
journal of oral rehabilitation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 93
eISSN - 1365-2842
pISSN - 0305-182X
DOI - 10.1046/j.1365-2842.2002.01026_4.x
Subject(s) - sleep bruxism , medicine , placebo , dentistry , visual analogue scale , physical therapy , orofacial pain , linear regression , physical medicine and rehabilitation , statistics , mathematics , electromyography , alternative medicine , pathology
Sleep‐related bruxism (SB) is a frequently encountered problem in the dental office, for which evidence‐based causal therapy possibilities are not yet available. We are currently performing a large‐scale double‐blind placebo‐controlled randomized clinical trial to evaluate several management strategies for SB. So far, we have measured 35 participants, all of them clinically diagnosed bruxers (11 men; 24 women; mean age=39·2 ± 11·4 years). A first (baseline) night in the sleep laboratory confirmed their clinical diagnosis, i.e. all had more than four bruxism episodes per hour of sleep; (> 4 EpiH). The baseline recordings were preliminarily analysed to establish a cut‐off criterion for a polysomnographical SB diagnosis that, in addition to the previously established criterion (i.e. > 4 EpiH), also respects the time spent bruxing. We therefore calculated an index that expresses this aspect as a percentage of the total sleep time: the bruxism time index (BTI). The BTI was highly correlated with the number of EpiH (Pearson's correlation coefficient=0·92; P =0·000). Linear regression analysis revealed that a BTI of > 0·4% corresponds with the > 4 EpiH criterion ( F ‐value for the significance of the overall model=146·2; P =0·000). Future analyses may yield an additional intensity (power) cut‐off criterion as well. As the relationship between SB and jaw pain is still unclear, we also determined, in 28 of the 35 participants, the influence of self‐reported (VAS) jaw pain during mouth opening before and after the first night on the BTI. BTIs in bruxers whose evening and/or morning VASs ≥ 10 mm ( n =10) tended to be lower than those in bruxers whose VASs were less than 10 mm ( n =18) (1·4 ± 1·0 and 2·7 ± 2·5%, respectively; Two sample t ‐test; T =1·98; P =0·059). This finding confirms previous suggestions in the literature that jaw pain might be associated with a reduced bruxism activity . This can be understood as a protective mechanism that prevents (further) overloading of the masticatory system. (Supported by the IOT.)