Tooth wear: a discriminator between young sleep bruxers and controls?

OBJECTIVE: Sleep bruxism, characterized by tooth grinding and clenching, may damage tooth and exacerbate headaches or temporomandibular disorders. Clinical recognition of sleep bruxism is frequently based on a history of tooth grinding and tooth wear. The aim of this study was to investigate whether tooth wear can help to discriminate young sleep bruxers from control individuals.

METHODS: The clinical examinations and sleep polygraphic data (2nd night) of 107 individuals (26.6 ±0.5 years) with clinical and sleep laboratory diagnostic of tooth grinding/sleep bruxism were compared with those of 23 control subjects (26.6 ±1.5 years). Based on the frequency of EMG events in subjects with a current history of tooth grinding, the sleep bruxer population was divided into 2 subgroups: low (< 4 events/hr) and moderate-high. Tooth wear for each tooth was scored using Johansson's criteria (index 0-4, J Oral Rehabilitation 1993). All scores were pooled and individualized for incisor, cuspid and molar tooth types. The relationships between the 2 bruxer subgroups and the control group were evaluated using Kruskal-Wallis and Mann-Whitney U tests. Sensitivity and specificity of tooth wear were estimated using ROC curve.

RESULTS: Both sleep bruxer groups showed significantly higher mean tooth wear score (low bruxer group: 0.8/4, moderate-high bruxer group: 0.7/4) than the control group (0.03/4) for pooled and individualized scores (p<0.001). No difference was observed between low and moderate-high bruxer groups. To discriminate bruxers from controls, pooled tooth wear sensitivity was estimated at 94% and specificity at 87%; cuspids had the highest sensitivity (87%) and molars had the highest specificity (91%).

CONCLUSION: Tooth wear discriminate bruxers from control subjects. However, in the absence of a current history of tooth grinding, tooth wear alone is an insufficient indicator. Moreover, tooth wear does not discriminate the severity of sleep bruxism.

(Supported by CIHR)