Facial trauma and the compulsory seat belt law de Barros et al. Figure 1 - Absolute number of deaths in motorvehicle accidents according to the World Health Organization. 6,558,463 vehicles in the capital and 19,499,430 vehicles in the state in June 2009.11 Traumas According to WHO data, traumas are among the main causes of death and morbidity in the world. Every day, 16,000 people die as a result of some trauma.14 Among the various types of trauma, facial trauma is notable due to its emotional and functional consequences and the possibility of permanent deformities.15 The increased exposure and little protection increases the likelihood of serious injuries to this part of the body in car accidents. Head and face injuries represent about 50% of all traumatic deaths.16 Recognizing which etiologies are most prevalent and which population is most affected by face traumas is a fundamental part of structuring services. With the popula- tion growth, increasing traffic of motor vehicles, and socio- economic discrepancies, the number of traumatic facial fractures has increased,17 although fractures from sports activities are less frequent.18 In general, facial traumas are associated with other factors, such as assaults or falls.13,18 Results of a study of 450 individuals with facial fracture in the city of Sa˜o Paulo in the 1980s showed that the main cause of facial fracture was motorvehicle accidents.19 A study carried out more recently in a hospital in the south zone of Sa˜o Paulo20 found that the most frequent etiology of facial trauma was motorvehicle accidents (25% of cases) and motorcycle accidents (25%), whereas less frequent etiologies were physical assaults (15%) and work accidents (1%). Results of a retrospective study of 323 individuals with facial fractures due to motorvehicle accidents at the Sa˜o Paulo Clinics Hospital between February 2001 and July 2006 showed that the average age of the patients was 30.9 years and the proportion of men to women was 3.3 to 1 (see Table 1).21 The findings are consistent with the results of a Minas Gerais study, which found that 23% of facial injuries CLINICS 2010;65(10):1043-1047 were due to accidents involving bicycles and motorcycles, whereas 21% were due to interpersonal violence. In addi- tion, trauma to the face from motorvehicle accidents was found to be more common among men (80%) than women (20%).13 In Recife, motorvehicle accidents account for 31.8%, followed by physical assault (22.2%) and assaults with firearms (18.7%).22 On the other hand, in Porto Alegre, approximately 36% of facial fractures occur as a result of of urban violence.23 Traffic accidents (19%) were reported to be the second most common cause, together with sports accidents (19%). Seat belts In Sa˜o Paulo, a municipal law was passed that mandated the use of seat belts on November 4, 1994.3 Reactions for and against the law were immediate because of the difficulties and adjustments required for its implementation. However, all of this loses importance when it comes to lives and traumas.1 According to the Traffic Engineering Company (TEC),24 after two years of the Municipal Act’s requiring the use of seat belts, the measure was found to be beneficial to the physical safety of both drivers and front seat passengers of vehicles, as well as the entire population. The TEC conducted a survey of victims from the vehicles who received treatment at the emergency room at Santa Casa de Misericordia in Sa˜o Paulo (see Table 2). As shown in Table 2, there was a reduction in head injuries following the application of the law. Soriano et al.25 also reported a decrease of 4.9% in the frequency of ocular perforations caused by motorvehicle accidents after the implementation of the law. In 1997, the new National Traffic Code (NTC) was approved.4 Beginning in April 1998, individuals were punished for failing to use their seat belt. Individuals caught driving without wearing a seat belt or allowing a passenger to ride in their vehicle without wearing one received a fine of R$127.69 and five points on their driver’s license, constituting a serious violation. In Brazil, the mortality rate from motorvehicle accidents has declined from 29.8% in 1996 to 25.3% in 1999.26 This decline can be attributed to several factors, including lower speed limits, more surveillance, greater use of seat belts, the implementation of electronic speed bumps, and an increase in the car fleet.26 Between 1996 and 1998, there was a 30% reduction in the number of traffic deaths in Sa˜o Paulo because of the introduction of the new Brazilian Traffic Code and the installation of electronic radar cameras for speed surveillance in the city.27 According to results of a survey conducted in the region of Pelotas (RS), 26% of oral and maxillofacial fractures occur as a result of motorvehicle accidents.28 A similar rate of 29% was found in a study of jaw fractures in a hospital in Table 1 - Features of facial fractures occurrences in motorvehicle accidents according to data from a large Sa˜ o Paulo hospital (2007).21 Table 2 - Location of injuries in vehicle occupants injured before and after the municipal law mandating the use of seat belts was instituted in Sa˜ o Paulo.24 Number of patients With seat belt Without seat belt Total Location of injuries Before the seat belt law After the seat belt law Driver Front seat passenger Rear seat passenger Total 60 44 0 104 58 67 94 219 118 111 94 323 Head Body Upper members Lower members 44.2% 11.6% 15.8% 28.4% 30.6% 25.6% 19.1% 24.7% 1044