The trend demonstrates increased use of protective devices during 2007-2012 with stable to slightly decreased incidence of facial fractures. These data do not necessarily reflect generalizable results and may be owing to sampling or reporting differences in each reporting year.
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Hyman DA, Saha S, Nayar HS, Doyle JF, Agarwal SK, Chaiet SR. Patterns of Facial Fractures and Protective Device Use in Motor Vehicle Collisions From 2007 to 2012. JAMA Facial Plast Surg. 2016;18(6):455–461. doi:10.1001/jamafacial.2016.0733
What is the current incidence of facial fractures after motor vehicle collisions in patients treated at US trauma centers and what is the influence of protective devices?
From 2007 to 2012, the incidence of at least 1 facial fracture was 10.9%; use of airbags, seat belts, and the combination of the 2 devices incrementally reduced the likelihood of a facial fracture.
Approximately 11% of patients who present to a US trauma center after a motor vehicle collision have at least 1 facial fracture; airbags and seat belts are significantly protective against such fractures.
Facial fractures after motor vehicle collisions are a significant source of facial trauma in patients seen at trauma centers. With recent changes in use of seat belts and advances in airbag technology, new patterns in the incidence of facial fractures after motor vehicle collisions have yet to be quantified.
To evaluate the incidence of facial fractures and assess the influence of protective device use in motor vehicle collisions in patients treated at trauma centers in the United States.
Design, Setting, and Participants
Using a data set from the National Trauma Data Bank, we retrospectively assessed facial fractures in motor vehicle collisions occurring from 2007 through 2012, reported by level I, II, III, and IV trauma centers. Data analysis was performed from March 13 to September 22, 2015.
Main Outcomes and Measures
We characterized the data set by subsite of facial injury using International Classification of Diseases, Ninth Revision codes including mandible, midface, and nasal fractures. We assessed the influence of variables such as age, sex, race/ethnicity, crash occupant (driver or passenger), use of protective device, and presence or suspicion of alcohol use.
A total of 518 106 patients required assessment at a trauma center after a motor vehicle collision, with 56 422 (10.9%) experiencing at least 1 facial fracture. Nasal fracture was the most common facial fracture (5.6%), followed by midface (3.8%), other (3.2%), orbital (2.6%), mandible (2.2%), and panfacial fractures (0.8%). Of the subset sustaining at least 1 facial fracture, 5.8% had airbag protection only, 26.9% used a seat belt only, and 9.3% used both protective devices, while 57.6% used no protective device. Compared with no protective device, the use of an airbag alone significantly reduced the likelihood of facial fracture after a motor vehicle collision (odds ratio, 0.82; 95% CI, 0.79-0.86); use of a seat belt alone had a greater effect (odds ratio, 0.57; 95% CI, 0.56-0.58) and use of both devices provided the greatest odds reduction (odds ratio, 0.47; 95% CI, 0.45-0.48). Younger age, male sex, and alcohol use significantly increased the likelihood of facial fracture.
Conclusions and Relevance
For patients who presented to US trauma centers after motor vehicle collisions between 2007 and 2012, airbags, seat belts, and the combination of the 2 devices incrementally reduced the likelihood of facial fractures.
Level of Evidence
Motor vehicle collisions (MVCs) are a significant cause of morbidity and mortality in the US population. According to the National Highway Traffic Safety Administration, 2.31 million people were injured and 32 719 people killed in MVCs in 2013.1 Motor vehicle collisions represent a significant source of facial fractures treated at US trauma centers.2,3
Airbags and seat belts are designed to decrease morbidity and mortality in MVCs. In the United States, seat belts have been required in vehicles for almost 50 years. Owing to more stringent seat belt laws during the past decade, rates of seat belt use in the United States increased from 71% in 2000 to 87% in 2013.4 Although General Motors implemented airbags in the 1970s, driver-side airbags were not required in passenger cars until 1989; dual front airbags became a requirement for cars and small trucks in 1998.5 Since its widespread introduction, airbag technology has continued to improve, and US law required certified advanced airbags by the production of 2007 model-year vehicles.6 These airbags measure crash severity and identify occupant seat belt status, weight, and proximity to the airbag. Over time, older vehicles without airbags or with outdated airbag technology are replaced on the road with newer vehicles with dual front airbags, certified advanced airbags, and side airbags.
With regard to facial fractures in MVCs, the effect of seat belts and airbags continues to be an area where researchers’ understanding is evolving. Studies from the 1980s through 2005 demonstrated that seat belts alone and the combination of airbags and seat belts significantly reduce the likelihood of facial fractures in MVCs, although there is little evidence supporting that airbags alone provide significant protection when no seat belt is worn.5,7-11 Stacey et al12 used the National Trauma Database (now National Trauma Data Bank [NTDB]), to show the incidence of facial fractures and lacerations in MVCs from 2000 to 2004 and the protective effects of safety device use. They found that the lack of a safety device was associated with an increased incidence of facial fracture in MVCs (odds ratio [OR], 2.26; 95% CI, 2.18-2.35). Since that study, the NTDB underwent a major update in 2006 to improve data quality, which provided standard definitions and criteria for the submission of trauma data.13
Owing to the changing national pattern of seat belt use and continued advancement of airbag technology in newer vehicles, as well as the replacement of older vehicles on the road, we expect a decreasing trend of facial fractures in MVCs and improved protective role of protective devices. The objectives of this study were to use the NTDB to evaluate the incidence of facial fractures in MVCs from 2007 to 2012 and assess the influence of seat belt and airbags in patients treated at trauma centers in the United States.
A retrospective analysis was performed using data from the NTDB from 2007 to 2012. The NTDB is a trauma registry containing detailed trauma data submitted from more than 800 registered level I, II, III, or IV US trauma centers.14 The NTDB is a not a population-based data set but rather is dependent on voluntary data submissions from US trauma hospitals. Patients not admitted to the hospital, including those with minor injuries or who died before arrival, are not included in the data set. However, patients who present to the emergency department and are subsequently discharged are included in the data set. The University of Wisconsin School of Medicine and Public Health did not require institutional review board approval or written patient consent for analysis of this deidentified database.
The database was queried for individuals 18 years or older involved in an MVC. Next, these individuals were screened for facial fractures according to the International Classification of Diseases, Ninth Revision (ICD-9) codes representing fractures of the mandible (codes 802.20-802.39), maxilla or malar (codes 802.4-802.5), orbital floor (codes 802.6-802.7), nasal bones (codes 802.0-802.1), or fracture of other facial bone (codes 802.8-802.9). Patients with multiple ICD-9 codes representing multiple fractures were included in each category for analysis. We defined a panfacial fracture as any patient with both a mandible fracture and midface fracture, where a midface fracture includes a malar or maxillary fracture, orbital floor fracture, or both. Owing to the limitations of the ICD-9 system, fractures of the upper one-third of the facial skeleton as well as the skull base could not be categorized separately, and may be included with fracture of other facial bone (codes 802.8-802.9) or with other nonspecific trauma codes. Facial laceration ICD-9 codes were not included.
Patient demographics and characteristics analyzed were age, sex, race/ethnicity, crash occupant (driver or passenger), use of protective device, and presence or suspicion of alcohol use. Protective device use was categorized as no device, airbag alone, seat belt alone, and both devices. Race/ethnicity was categorized as white, Native American, Hispanic, black, Asian, or other.
Finally, all patients with facial fracture after MVC were stratified by overall injury severity. We used the Injury Severity Score (ISS), a standardized system for trauma patients with multiple injuries with scores assigned for 6 body regions (head, face, chest, abdomen, extremities [including pelvis], and external), to analyze if the effects of protective devices were significant in both minor and major traumatic injuries.15
Data analysis was performed from March 13 to September 22, 2015. We examined differences in characteristics between patients who did or did not sustain a facial fracture after an MVC using t tests and χ2 tests. The overall incidence of different types of facial fractures and use of protective devices across the study period were tabulated.
To evaluate the effects of the different variables on the 3 events (any facial fracture, panfacial fracture, and nasal fracture), we used a multivariable logistic regression analysis using PROC LOGISTIC in SAS, version 9.3 (SAS Institute). The ORs and corresponding 95% CIs were calculated. P < .05 was considered significant. Patients were stratified for ISS less than 9, between 9 and less than 16, between 16 and less than 25, and 25 or more, and ORs for any facial fracture were recalculated within each ISS subset.
In the NTDB data set from 2007 to 2012, a total of 518 106 individuals were involved in an MVC and required assessment at a level I-IV trauma center. Of those individuals, 56 422 sustained a facial fracture (10.9%). Nasal fracture was the most common facial fracture (5.6%), followed by midface (3.8%), other (3.2%), orbital (2.6%), mandible (2.2%), and panfacial fractures (0.8%).
Of the patients who presented after MVCs, 5.1% had airbag deployment only, 36.3% used a seat belt without airbag deployment, and 15.5% used both, while 42.6% used no device and it was not known what device 0.5% used. Of the subset sustaining a facial fracture, 5.8% had airbag deployment only, 26.9% used a seat belt only, and 9.3% used both, while 57.6% used no device and it was not known what device 0.4% used. For those with panfacial trauma, 4.8% had airbag deployment only, 22.9% used a seat belt only, and 6.8% used both, while 64.9% used no device and it was not known what device 0.6% used. The frequency of no protective device use was higher in both the panfacial fracture cohort and the any facial fracture cohort compared with the entire cohort of individuals involved in MVCs.
Demographics of the cohorts with and without facial fracture showed statistical differences in regards to age, sex, race/ethnicity, use of protective devices, and use of alcohol (Table 1). Those with facial fracture were younger than those without facial fracture (mean [SD] age, 37.5 [27.0] vs 41.2 [18.8] years; P < .001) and more likely to be male (68.3% vs 57.2%; P < .001) and use alcohol (31.8% vs 20.4%; P < .001). Those with facial fracture and those without were drivers of the collisions in nearly equal amounts (75.9% vs 75.8%, respectively; P = .49). Individuals with facial fracture were more likely to have not used a protective device (57.6% vs 40.7%; P < .001), and the combination of seat belts with airbags was significantly less frequent among those with facial fracture (9.3% vs 16.3%; P < .001).
The influence of demographics (age, sex, race/ethnicity), use of alcohol, crash occupant (driver vs passenger), and use of protective devices was analyzed with multivariable logistic regression to determine the likelihood of facial fractures in individuals experiencing MVCs. Individuals for whom the type of protective device used was unknown were excluded from further analysis. For any facial fracture, when adjusted for other variables, male sex (OR, 1.39; 95% CI, 1.36-1.42; P < .05) and alcohol use (OR, 1.46; 95% CI, 1.43-1.49; P < .05) were associated with increased likelihood of facial fracture (Table 2). Use of airbag alone significantly reduced the likelihood of facial fracture compared with no protective device (OR, 0.82; 95% CI, 0.79-0.86; P < .05). Use of a seat belt alone had an even greater effect (OR, 0.57; 95% CI, 0.56-0.58; P < .05) and use of both protective devices provided the greatest odds reduction in facial fracture (OR, 0.47; 95% CI, 0.45-0.48; P < .05). Older age (10-year difference) and nonwhite race/ethnicity also conferred small yet statistically significant decreases in likelihood of facial fracture. Seat occupancy (driver vs passenger) did not show a significant effect on the risk of facial fracture. In patients with panfacial fractures, similar statistically significant findings were observed, but with a greater magnitude of odds reduction, by airbags alone (OR, 0.62; 95% CI, 0.54-0.72; P < .05), seat belts alone (OR, 0.48; 95% CI, 0.44-0.51; P < .05), and the combination (OR, 0.34; 95% CI, 0.30-0.39; P < .05).
The same trends were observed in patients with nasal fractures (Table 2). The odds reduction seen with airbags alone (OR, 0.93; 95% CI, 0.88-0.98; P < .05) was smaller than that observed for patients with any facial fracture or with panfacial fracture, but showed a similar pattern of reduced likelihood with seat belt alone (OR, 0.62; 95% CI, 0.61-0.64; P < .05) or both devices (OR, 0.54; 95% CI, 0.52-0.57; P < .05). Passenger seat occupancy significantly decreased the likelihood of nasal fractures, although the magnitude of this effect was small (OR, 0.93; 95% CI, 0.91-0.96; P < .05).
Patients with facial fracture after an MVC were stratified in the NTDB from minor to major injuries by ISS. The mean (SD) ISS for patients with facial fracture after an MVC was 28.8 (18.2), where 0 is no injury and 75 is a fatal injury. A total of 14.9% of patients had an ISS less than 9, 20.3% had an ISS between 9 and less than 16, 14.1% had an ISS between 16 and less than 25, and 50.7% had an ISS of 25 or more. Within each ISS subgroup of patients with facial fracture, multivariable analysis was performed independently for each severity level of total body injury, confirming the trends identified in facial fractures after MVCs. Male sex and alcohol use were associated with increased likelihood of facial fracture, while older age and use of protective devices reduced the likelihood of facial fracture across all ISS subgroups (Table 3). The effects of airbag alone, seat belt alone, or both devices still significantly reduced the odds of facial fracture, although less so at higher ISS (for patients with ISS of 25 or higher, OR, 0.91; 95% CI, 0.86-0.96; OR, 0.66; 95% CI, 0.64-0.68; and OR, 0.53; 95% CI, 0.51-0.56, respectively; P < .05).
We used NTDB data from 2007 to 2012 to evaluate the incidence of facial fractures and the effect of the use of protective devices on facial fractures in individuals presenting to US trauma centers after MVCs. We hypothesized that with recent changes in seat belt legislation and airbag design, the incidence of use of airbags alone, use of seat belts alone, and use of the 2 devices together has changed.
In this study cohort, the patients with facial fracture were significantly more likely to be younger, male, not using protective devices, and under the influence of alcohol. The findings reflect MVCs with injuries significant enough to warrant evaluation at a level I to IV trauma center, in the most recent era.
The incidence of facial fracture after MVCs from 2007 to 2012 is 10.9%, which reflects the proportion of facial fractures that may be encountered in patients involved in an MVC who then present to a US level I to IV trauma center. Although this incidence of facial fractures is substantially higher than the 5.6% reported by Stacey et al12 using NTDB data from 2000 to 2004, their analysis excluded nasal fractures. If we exclude nasal fractures in our study, the incidence of nonnasal facial fractures is 5.3%, which closely approximates that found by Stacey et al.
Use of protective devices was less common among patients with facial fracture. Compared with all individuals in MVCs who presented to trauma centers and with the cohort without facial fractures, those with any facial fracture had a higher incidence of no use protective devices (42.6%, 40.7%, and 57.6%, respectively). Although use of airbag alone was similar among the 3 cohorts (5.1%, 5.0%, and 5.8%, respectively), patients with any facial fracture showed less use of seat belts (36.3%, 37.4%, and 26.9%, respectively) and less frequent combined use of both devices (15.5%, 16.3%, and 9.3%, respectively). This trend was more pronounced among patients with panfacial fractures. This pattern in use of protective devices is comparable with that in the study by Stacey et al,12 in which the facial fracture cohort had a higher incidence of no restraint use compared with all individuals in MVCs (59% vs 45%), a lower incidence of use of a seat belt only (31% vs 41%), seat belt plus airbag (6% vs 10%), and an equal incidence of use of airbag only (4% vs 4%).
The use of airbag alone significantly reduced the likelihood of sustaining any facial fracture by 18% compared with using no protective device, use of a seat belt alone decreased the likelihood by 43%, and the combination of seat belt and airbag decreased the likelihood by 53% (P < .05). Although the protective benefit of seat belt alone and the combination of seat belt and airbag have been well described in the literature, to our knowledge, the protective benefit of airbags alone in preventing facial fractures has been found to be statistically significant only once in a study by Cormier and Duma,16 who used National Automotive Sampling System Crashworthiness Data System data from 1993 to 2007 to demonstrate that airbags alone were significantly protective.
Improvements in airbag technology may explain the protective benefit of airbags alone. Other studies have examined the use of airbags between 1991 and 2005. First-generation front airbags were designed for an impact of any speed up to 30 miles per hour into a fixed rigid barrier perpendicular to the line of travel of the vehicle with adult men in the 50th percentile for size who were both using a seat belt and not using a seat belt. It was not until the mid-1990s to late 1990s, owing to concern about airbag-related deaths from inflation force, that legislation was relaxed with the introduction of depowered airbags in 1998.17 Finally, owing to a legislative push in 2000 for more sophisticated front airbags by 2007, new certified advanced airbags began to appear and became a requirement by 2007. Certified advanced airbags carefully tailor deployment according to sensors that account for severity of impact, use of seat belt, and size of the occupant of the seat.6 As our data set examined trends in facial fractures from 2007 to 2012, it is possible that the implementation of certified advanced airbags, as well as the scrapping of cars with older airbag systems accounts for the protective effect of airbags alone and when used in combination with seat belts.
The most common fracture after an MVC was the nasal bone, followed by midface fractures. Nasal bone fractures are consistently the most common facial fracture seen after MVCs in the literature.9,18 Restraint devices and, to a greater extent, airbags were far less protective regarding the diagnosis of nasal bone fracture after MVC compared with general facial fracture. An airbag alone decreased the likelihood of nasal fractures by only 7%. The nasal bone is the most projected portion of the face and it has been demonstrated that far less force is required to fracture the nasal bones compared with the surrounding facial bones.19 In frontal collisions, without the decrease in forward velocity provided by seat belts, the impact with the airbag may still produce enough force to cause a nasal fracture. However, airbags alone were still significantly protective against nasal fractures compared with no safety device. Passenger seat occupancy was protective against nasal fractures compared with driver seat occupancy, a pattern found only with nasal fractures. The steering wheel is a recognized source of facial fractures, even when accounting for use of protective devices, compared with the A-pillar (which holds either side of the windshield in place) or dashboard.18 It is likely that driver impact with the steering wheel and the lower force needed to cause a nasal fracture accounts for this pattern. However, there was still an odds reduction with all protective devices, even in the driver seat.
After accounting for use of protective devices, younger age, male sex, and alcohol use independently increased the likelihood of facial fracture. These factors also increase the overall incidence of MVCs. The National Highway Traffic Safety Administration found recognition error from inattention and distraction, decision error such as driving too fast for conditions, and performance error such as overcompensation or poor directional control as factors that influence the likelihood of an MVC.20 Such errors have been shown more likely to be made by younger, inexperienced, inebriated, and male drivers.21 The NTDB data do not indicate speed or type of collision, factors that may increase the incidence of MVCs in younger, male, or inebriated drivers.
Analysis of ISS was performed to serve as a proxy measure of accident severity. Higher ISS representing major injuries likely represent more severe collisions. Injury severity scores were widely distributed across the facial fracture cohort, suggesting a range of accident severity. Across the range of accident severities, all combinations of protective devices significantly decreased the likelihood of facial fractures. This finding suggests that airbags, seat belts, and the combination of the 2 devices decrease the likelihood of facial fracture for both minor accidents and major collisions.
A strength of this study is the representative sample size. The NTDB is the largest trauma database and includes data from level I to IV trauma centers across the United States. Thus, compared with regional or state trauma databases that may be influenced by local prehospital care systems, state seat belt laws, and variation of age of vehicles, the NTDB results are more generalizable across the United States. Although the NTDB data does not provide crash details seen in other smaller databases, it does provide the largest sample size.
There are limitations to the NTDB, such as yearly changes in participating institutions. The number of reporting institutions varies by year, making year-to-year comparisons imprecise and methodologically challenged. Despite the possibility of sampling error, there was an increased incidence in seat belt use (alone or combined), airbag use (alone or combined), and both in individuals who presented after MVC during the study years (Figure). This finding is striking because the frequency of facial fracture in the cohort shows a slight decrease from 10.7% to 10.5% during the same years. These data do not necessarily reflect generalizable results and may be owing to sampling or reporting differences in each reporting year. Further investigation is necessary to determine the significance of increasing seat belt use and airbag use within the NTDB data while facial fracture incidence remained stable or decreased slightly during the same period.
Another limitation is the constrained crash variables included in the NTDB. Factors such as speed or type of collision, consistent reporting of side airbag deployment, and vehicle type are not included in the registry. Despite these limitations, the incidence of facial fractures in MVCs and trends identified can be considered strongly applicable to a patient who presents to any US trauma center after experiencing an MVC.
The incidence of facial fracture from MVCs in individuals who present to trauma centers in the United States was 10.9%, with nasal fractures being the most common fracture type, followed by midface fractures. Airbags, seat belts, and the combination of the 2 devices incrementally reduce the likelihood of facial fracture compared with no protective device. This trend may be owing to recent advances in airbag technology during the last 10 to 15 years. Younger age, male sex, and the use of alcohol also increase the likelihood of facial fracture in MVCs. Not only has airbag deployment increased in patients who present to trauma centers after MVCs but airbags also appear to provide significant protection against facial fractures when deployed without seat belts.
Accepted for Publication: May 4, 2016.
Corresponding Author: David A. Hyman, MD, University of Wisconsin Division of Otolaryngology–Head and Neck Surgery, Department of Surgery, 600 Highland Ave, Madison, WI 53792 (firstname.lastname@example.org).
Published Online: July 21, 2016. doi:10.1001/jamafacial.2016.0733
Author Contributions: Dr Chaiet had full access to all the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Hyman, Nayar, Agarwal, Chaiet.
Acquisition, analysis or interpretation of data: Hyman, Saha, Doyle, Chaiet.
Drafting of the manuscript: Hyman, Saha, Nayar.
Critical revision of the manuscript for important intellectual content: Hyman, Doyle, Agarwal, Chaiet.
Statistical analysis: Saha, Nayar, Chaiet.
Administrative, technical, or material support: Hyman, Nayar, Agarwal.
Study supervision: Nayar, Doyle, Agarwal.
Conflict of Interest Disclosures: None reported.
Previous Presentation: This study was presented at the Combined Otolaryngology Spring Meeting, American Academy of Facial Plastic and Reconstructive Surgery Section; April 23, 2015; Boston, Massachusetts.
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