INTRODUCTION Cranio-maxillofacial trauma management requires pertinent documentation. Using a large computerized database, injury surveillance and research data describe the whole spectrum of injuries. The goal of this study was to assess the effect of the five main causes of accidents resulting in facial injury on the severity of cranio-maxillofacial trauma. PATIENTS AND METHODS During a period of 10 years (1991-2000) 9,543 patients were admitted to the Department of Oral and Maxillofacial Surgery, University Hospital of Innsbruck with cranio-maxillofacial trauma. Data of patients were prospectively recorded including cause of injury, age and gender, type of injury, injury mechanisms, location and frequency of soft tissue injuries, dentoalveolar trauma, facial bone fractures and concomitant injuries. Statistical analyses performed included descriptive analysis, chi square test, Fisher's exact test, and Mann-Whitney's U test. This was followed by logistic regression analyses for the three injury types to determine the impact of the five main causes on the type of injury at different ages in facial trauma patients. RESULTS Five major categories/mechanisms of injury existed: in 3,613 (38%) cases it was activity of daily life, in 2991 (31%) sports, 1170 (12%) violence, in 1,116 (12%) traffic accidents, in 504 (5%) work accidents and in 149 (2%) other causes. A total of 3,578 patients (37.5%) had 7,061 facial bone fractures, 4,763 patients (49.9%) suffered from 6,237 dentoalveolar, and 5,968 patients (62.5%) from 7,769 soft tissue injuries. Gender distribution showed an overall male-to-female ratio of 2.1 to 1 and the mean age was 25.8+/-19.9 years; but both varied greatly depending on the injury mechanism (facial bone fractures: 35.4+/-19.5 years, higher risk for males; soft tissue injuries: 28.7+/-20.5, no gender preference; dentoalveolar trauma: 18+/-15.6, elevated risk for females). For patients sustaining facial trauma, logistic regression analyses revealed increased risks for facial bone fractures (225%), soft tissue lesions (58%) in patients involved in traffic accidents, and dental trauma (49%) during activities of daily life and play accidents. When compared with other causes, the probability of suffering soft tissue injuries and dental trauma, but not facial bone fractures, is higher in sports-related accidents, 12 and 16%, respectively. CONCLUSION This study differentiated between injury mechanisms in cranio-maxillofacial trauma. The specially trained surgeons treating cranio-maxillofacial trauma are the primary source of information for the public and legislators on implementing preventive measures for high-risk activities. In facial trauma, older persons are prone to bone fractures (increase of 4.4%/year of age) and soft tissue injuries (increase of 2%/year of age) while younger persons are more susceptible to dentoalveolar trauma (decrease of 4.5%/year of age).