This paper presents a review of injury dynamics of jaw fractures sustained by 1374 patients in the county of Stockholm during 1978-1980 = M1 (795 patients) and 1988-1990 = M2 (579 patients). The material comprised 1620 mandibular (M1 = 904, M2 = 716) and 439 maxillary (M1 = 249, M2 = 190) fractures. Forty-three per cent of the mandibular fractures and 40% of the maxillary fractures were single fractures in M1. The corresponding figures for M2 were 35% and 43%. During both periods the anatomical region most frequently fractured was the mandibular condyle (M1 = 35%, M2 = 29%). Violence was the cause in 39% of all fractures and 42% of the mandibular fractures (M2). This compared to M1 confirms other reports of altered trends in jaw fractures related to violence during the 1980's. The proportion of jaw fractures caused by traffic increased slightly between the periods.