Personality traits in a group of subjects with long-standing bruxing behaviour.

The personality pattern of 29 subjects, 10 men and 19 women, with a mean age of 37.7 years (range 23-68) was studied by means of a personality inventory (KSP) and compared with the personality traits of a 'normal population'. The bruxers had significantly higher scores in the somatic anxiety and muscular tension scales and lower scores in the socialization scale; that is, the bruxers were more anxiety-prone, had higher vulnerability for psychosomatic disorders and were less socialized. The frequent clenchers (once to twice a week) comprised a special subgroup within the material with higher values in the somatic anxiety, psychic anxiety and muscular tension scales. A strong correlation was found between high values in the muscular tension scale and headache; aching neck, back, throat or shoulders; tooth clenching; number of muscles tender at palpation and the clinical dysfunction index (Di). The results of this study indicate a possible aetiological relationship between personality, tooth clenching and craniomandibular dysfunction (CMD). However, the material was small and some precaution must be taken prior to generalization of the results. Studies on larger material are needed and especially more studies in sleep laboratories.