Association between CMD signs and symptoms, oral parafunctions, race and sex, in 4-6-year-old African-American and Caucasian children.

The associations between oral parafunctions, signs and symptoms of craniomandibular disorders (CMD), race, and sex were analysed in recordings from 203 4-6-year-old African-American and Caucasian children. Significant correlations were found between bruxism, nail biting, thumb sucking and most of the CMD signs and symptoms. There were also significant associations between most of the signs and symptoms and race, while significant association with sex was found only regarding headache, TMJ sounds and chewing pain. Significant associations were found between most CMD signs and TMJ sounds supporting the view that joint sound recordings have diagnostic value. There were also significant associations between the pain variables recorded by questionnaire and those recorded by palpation, which indicates that reliable data can be obtained by interviewing children as young as five. The results of this study support the concept that oral parafunctions have a significant role in the aetiology of CMD. The results also show that race and sex need to be considered when analysing the possible aetiological role of oral parafunctions in CMD. Longitudinal studies, beginning with low age groups are needed to better determine the role of childhood oral parafunctions in CMD aetiology.