A multicentric, prospective study on oral and maxillofacial trauma in the female population around the world

Abstract Background/Aims Approximately 20% of patients with maxillofacial trauma are women, but few articles have analysed this. The aim of this multicentric, prospective, epidemiological study was to analyse the characteristics of maxillofacial fractures in the female population managed in 14 maxillofacial surgery departments on five continents over a 1‐year period. Methods The following data were collected: age (0–18, 19–64, or ≥65 years), cause and mechanism of the maxillofacial fracture, alcohol and/or drug abuse at the time of trauma, fracture site, Facial Injury Severity Scale score, associated injury, day of trauma, timing and type of treatment, and length of hospitalization. Results Between 30 September 2019 and 4 October 2020, 562 of 2387 patients hospitalized with maxillofacial trauma were females (24%; M: F ratio, 3.2:1) aged between 1 and 96 years (median age, 37 years). Most fractures occurred in patients aged 20–39 years. The main causes were falls (43% [median age, 60.5 years]), which were more common in Australian, European and American units (p < .001). They were followed by road traffic accidents (35% [median age, 29.5 years]). Assaults (15% [median age, 31.5 years]) were statistically associated with alcohol and/or drug abuse (p < .001). Of all patients, 39% underwent open reduction and internal fixation, 36% did not receive surgical treatment, and 25% underwent closed reduction. Conclusion Falls were the main cause of maxillofacial injury in the female population in countries with ageing populations, while road traffic accidents were the main cause in African and some Asian centres, especially in patients ≤65 years. Assaults remain a significant cause of trauma, primarily in patients aged 19–64 years, and they are related to alcohol use.


| INTRODUC TI ON
The epidemiology of maxillofacial trauma varies due to socioeconomic, demographic and environmental factors, and the subject is often a young male. [1][2][3] One of the main limitations of most previous epidemiological studies on maxillofacial trauma is their retrospective nature, regardless of being single-centre, multicentric 4,5 or based on a national database. [6][7][8] Although in the last 30 years women have acquired a greater socio-economic role and consequently they have a more active participation in activities outside home, becoming more susceptible to road accidents, urban violence or other causes of injury, there is still little interest in the literature regarding the epidemiology of maxillofacial trauma in the female population, with few articles dedicated to this topic, 3,5,9,10 and most have focused on trauma caused by violence. 1,2,[11][12][13][14][15] Building upon the previous experience of the European maxillofacial trauma (EURMAT) project, 9 the trauma team of the oral and maxillofacial surgery unit in Turin, Italy, together with other thirteen centres worldwide, launched the world oral and maxillofacial trauma (WORMAT) project. The aim of this study was to evaluate oro-maxillofacial trauma epidemiology in the female population around the world in an attempt to provide a global picture of this phenomenon. Knowledge of these epidemiological data is critical to tailor preventive measures and to assess their proficiency, to predict trauma patterns and to effectively allocate resources.

| RE SULTS
During the study period, 562 of 2387 patients hospitalized with oral and maxillofacial trauma were females (24%; M:F ratio, 3.2:1) aged between 1 and 96 years (median age, 37 years; IQR-interquartile range-38). As shown in Figure 1, most fractures occurred in patients aged 20-39 years. The male:female ratio was higher in African (3.9:1) and Asian (4.0:1) units than in European, American and  [48%] in the male population) and proved to be statistically more frequent in patients ≤65 years (p < .001). Furthermore, RTAs were significantly more common in African and Asian centres than in the other centres (p < .001). In Oceania, the frequency of RTAs was the lowest (n = 1; 2%). Of the 72 patients who had been injured in car accidents (7 drivers and 65 passengers), 53 were not wearing seat belts, while of the 58 involved in motorcycle accidents (21 drivers and 37 pillion passengers), 47 were not wearing helmets.
The remaining 66 patients were cyclists or pedestrians ( Table 2).
When RTAs were involved, middle third (52%) and lower third (44%) fractures of the face were common. in the male population), 80% of whom were punched or kicked).
Patients aged 19-64 years were significantly more involved in assaults (21%) than those in other age groups (7% of 0-18 years and 2% for ≥65 years; p < .001 for both comparisons; Table 2). The highest assault frequency was found in American units (26% of all causes), which was significantly higher than in the African and Australian units (both 8%; p < .001 for both comparisons), but not significantly different from the Asian and European centres (p = .101 and p = .05, respectively). When assault was the cause of trauma, middle third fractures of the face were the most frequent (60%), followed by fractures of the lower third of the face (38%).
The fourth most common cause of trauma was a sports injury ( (7), team ball/stick and racquet sports (5), and wheeled non-motor sports (5). The remaining 10 patients were injured while participating in other sports (  Table 3).
The 0-18 year age group included 96 patients (17%) with fractures mainly due to RTAs (n = 37) and falls (n = 36; Table 2). The lower third of the face was affected slightly more often than the middle third (69 and 67 fractures, respectively;  Table 4). Nine of the 125 patients were operated on within 24 h. In this age group, 85 patients did not undergo surgical treatment, 35 underwent ORIF, and 5 underwent closed reduction. The average hospital stay was 3.5 days.

| DISCUSS ION
The most recent epidemiological reviews of maxillofacial trauma worldwide have reported that about 20% of patients are female. [12][13][14] Shayyab et al. 12 found that the male:female ratio was higher in developing than in developed countries. Boffano et al. 13 reported lower male:female ratios in Europe, America and Australia, ranging from 1.8:1 to 6.6:1, and they were higher in Asia and Africa, ranging from 2:1 to 20:1. Both Chrcanovic 15 and Lee 16 observed a trend towards a reduced male bias over the last 30 years, attributed 'to a changing workforce and to the fact that increasing numbers of women are working outdoors in more high-risk occupations, thus becoming more exposed to RTAs and other causes of maxillofacial fractures'. 15 In this first multicentre prospective study on this subject, the proportion of female cases of maxillofacial trauma was 24%, which is consistent with the literature. 9,17,18 In addition, the male:female ratio was lower in European, American and Australian units compared with the African and Asian units.
In recent years, falls and assaults have become more frequent causes of maxillofacial trauma than RTAs in developed countries. 3,13,16 Falls in the female population disproportionally affect the elderly, and the proportion of elderly persons in the general population is increasing due to their longer lifespan. [12][13][14][15][16] It is therefore not surprising that, in four of the five European centres, and in others where the average patient age exceeded 40 years, falls (slipping, tripping or stumbling, usually followed by a ground impact) were the main cause of fractures (42%-82% of cases; Table 3). In patients aged ≥65 years, falls caused 87% of fractures and were significantly more frequent than in other age groups. Consistent with the literature, fractures of the middle third of the face (particularly the OMZc and nose) were the most common in seven of nine departments, where falls were the main cause of injury. [17][18][19] The use of seatbelts in cars, wearing helmets while driving motorcycles, the strict control of speed limits and compliance with the laws related to drunk driving, combined with better road con- were more common than those of the middle third, as reported in several previous studies. 1,10,12,15,23 Assault was the third most common cause of maxillofacial fractures in the present study, and the incidence was similar to that reported by Hashemi et al. 11 and Zhou et al. 2 (Table 5). Consistent with the literature, these incidents more commonly involved women aged between 19 and 64 years (p < .001). 1,3,11 As found in this study and reported in the literature, assault is a more common cause of trauma in men than in women, but nevertheless it remains a significant problem in the female population. 2,9 Intimate partner violence, in particular, frequently involves female victims and is associated with oral and maxillofacial injuries which are therefore an important marker to recognize in the emergency department setting. [24][25][26] Many authors have pointed out that female patients often fail to declare the actual cause of trauma out of fear, embarrassment or low self-esteem, so the incidence of these injuries is likely to be under-estimated. 3,23,25 In line with the literature, women were typically assaulted with fists or with a combination of fists and kicks. As also found by Gerber et al., 23 assault was the most common cause of alcohol and/or drug abuse-related injuries (44% of all causes in this group). Alcohol and/ or drug abuse was also significantly associated with assaults, confirming the results of other studies. 11,15,23 Fractures of the middle third of the face were the main injuries. The nose, being most prominent in the face, was typically involved. 3,11,25 The low incidence of maxillofacial fractures occurring during sports is also in keeping with the literature, perhaps reflecting little interest in sports among female patients, especially contact sports, and a less aggressive playing style. 27 Although the number of injuries was relatively low, equestrian sports nevertheless caused the most fractures in this study, as also reported by several previous studies. [28][29][30] Surprisingly, ORIF was performed in less than 40% of the female patients with maxillofacial fractures. These results may reflect a preference to treat nasal bone fractures and mandibular condylar fractures conservatively in adults and children, and the higher risk of surgical complications in the elderly.

| CON CLUS IONS
This first prospective, multicentre epidemiological study showed

CO N FLI C T O F I NTE R E S T
The authors declare that there are no conflicts of interest.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.