An epidemiologic study of mandibular dysfunction dependence on different variables.

Age and sex characteristics of different signs and symptoms of mandibular dysfunction were studied in 600 randomly selected urban persons. With regard to mandibular mobility marked differences were observed between the sexes, and a steady decrease parallel with ageing. Against this, the percentages of the objective dysfunction signs of impaired mobility and TMJ-sounds, as well as those of the pooled percentages of all the objective signs (Di-I + II + III), increased parallel with ageing. The percentages of headache occurrence peaked in different age groups for men and women. Statistically significant correlations were found between headache, parafunctions, stress, age, the existence of a preferred chewing side, as well as several dental-occlusal factors, and the prevalence of mandibular dysfunction; between Ai and Di according to Helkimo, and between excessive tooth wear and parafunctions.