Synergistic effect of malocclusion and oral parafunctions on craniomandibular dysfunction in children with and without unpleasant life events

An epidemiological study was conducted on 386 children aged 6-10, with and without unpleasant life events, to investigate the synergistic effect of malocclusion and oral parafunctions on craniomandibular dysfunction. The results showed that the synergistic effect of certain occlusal factors and oral parafunctions was significantly correlated with clicking and symptoms of dysfunction in both groups and with TMJ and muscle tenderness in subjects without unpleasant life events. In children with unpleasant life events TMJ and muscle tenderness were not correlated with any combination of malocclusion and oral parafunction. The present study suggests that the synergistic effect of malocclusion and oral parafunctions is a 'sufficient' cause for development of clicking and symptoms of dysfunction in both groups and TMJ and muscle tenderness in subjects without unpleasant life events. Also, in children with unpleasant life events, other aetiologic factor(s) can be responsible for the development of TMJ and muscle tenderness.