Relationship between craniomandibular dysfunction and oral parafunctions in Caucasian children with and without unpleasant life events.

An epidemiological study was conducted to investigate the relationship between craniomandibular dysfunction and oral parafunctions in 386 children aged 6-10 years with and without unpleasant life events. The results showed statistically significant correlations between grinding, clenching, lip/cheek biting and muscle tenderness or pain, and clicking in subjects without unpleasant life events. Also, significant correlations were found in the same group between these parafunctions and difficulties in opening wide and pain on movements. When the definitional symptoms of craniomandibular dysfunction were aggregated, the chi-square test revealed significant correlations between them and the same oral parafunctions. The correlations in subjects with unpleasant life events between grinding, clenching, lip/cheek biting and each sign and symptom of craniomandibular dysfunction were close to the significance level. No significant correlations were detected between the definitional symptoms and these parafunctions in this group. The present study suggests that in patients without unpleasant life events grinding, clenching, and lip/cheek biting cannot be considered 'necessary' but can be 'sufficient' cause for the development of craniomandibular dysfunction. In subjects with unpleasant life events the origin of signs/symptoms of the dysfunction can be attributed to muscle tension or to another unknown aetiological factor.