Injuries to the maxillofacial region are a common occurrence, mainly due to their prominence and vulnerability compared to other parts of the body. The aetiology of injuries to the face can vary greatly from one country to another and even within the same country depending on local laws and customs [1, 2].

The male-to-female ratio of the non-indigenous cohort mirrored that of other studies, with a very strong male preponderance due to association with risk factors such as IPV [3,4,5]. Males are also more likely to migrate, and this will in turn be reflected in the numbers involved in any injuries involving the maxillofacial region.

Over half of the patients in this study originated from Eastern Europe (52.4%), this compares to those from South East Asia (2.2%). This is likely to be due to the geographical proximity, in addition to the freedom of movement within Europe. Europeans tend to have a higher alcohol consumption rate when compared to Southeast Asian, African, and Middle Eastern populations [13]. This may also contribute to the over-representation of this cohort in the study.

This study shows that those living in Ireland between 2 and 10 years were more likely to sustain maxillofacial fractures. This compares to those who were new to the country and residing for more than 10 years. The reason for this large cohort may be due to assimilation into the local culture and environment, whereas individuals residing longer may be older in age.

Most of the facial fractures in the study were sustained in early adult life to middle age, with two peaks at 16–30 years and 31–50. Most studies have shown that facial injuries occur in a younger age group due to various activities associated with that stage of life, e.g., IPV and alcohol consumption.

In developed countries, the most common cause of maxillofacial injuries is interpersonal violence, whereas in developing regions, several studies have reported a strong association with road traffic accidents [3, 7, 14].

In our study, the most common mechanism of injury was interpersonal violence 60.5%, which in turn was followed by falls 21.1%. It is worth noting that while many of these patients are from low income countries, IPV remains the most common mechanism of fracture.

Fractures caused by RTA were only seen in 6.1% of patients; this may be a testament to the strict Irish road trafficking laws. A national survey conducted in 2017 showed 94% compliance with seatbelt usage nationwide [15]. A recent multicentre study from Israel showed that vehicle drivers also accounted for a small component of maxillofacial fractures nationally [16].

Whereas IPV was the most common mechanism of injury, the zygomatic-maxillary complex was the most common fracture sustained, followed by orbit and nasal bones. This suggests that trauma as a result of blunt force to the face as the most common cause of maxillofacial injury in this group.

Alcohol consumption was commonly associated with the cohort of patients who were involved in alleged assault (76.9%). Therefore, it is reasonable to suggest that IPV whilst intoxicated is the most prevalent mechanism of maxillofacial injury in the non-indigenous patient. To analyse this further, a comparison of patients native to Ireland presenting with maxillofacial injuries should be identified to highlight any potential differences or similarities to how patients present.

Overall, the consumption of alcohol was associated with 22.8% of patient presentations which echoes findings from a previous study by Ugboko et al. in a Nigerian population [17]. This confirms the known risk of alcohol consumption as an aetiological factor in maxillofacial injuries [18, 19]. It may be suggested that the rate of alcohol-related facial injuries is much higher than that we have recorded in this study, as it was not possible to accurately record the intoxication status of the assailant.

Most injuries in our study occurred on a Friday and Saturday, with (24.8%) and (23.2%) respectively. This is similar to many studies that show most injuries occurred at the weekends on both Friday [20, 21] and Sunday [18]. This trend is most likely to be observed due to increase in alcohol-related social interactions and activities, but also due to individuals undertaking sporting activities and car journeys, all of which have been seen as potential causes of maxillofacial fractures.

Monday saw the least amount of injuries occurring (8.8%), and a similar pattern was observed with patients from both urban and rural areas.

As 60.5% of the patients from this study sustained their injuries as a result of alleged assault, it would be reasonable to consider that motivation of assault may have racial implications. From this cohort, we found that police were involved in 125 cases where 100 patients sustained an injury as a result of assault. From these 100 patients, only 32% patients knew their assailant. This therefore highlights the thought that assault in the non-indigenous group may be motivated racially.

Fractures of the zygomatic complex were the most commonly affected bone in this study group at 31.04%, whereas mandibular fractures have been previously reported as the most common fracture pattern in other studies [1, 5]. The injury which occurred the least was fractures in a Le Fort pattern, with most Le-Fort fractures were caused by high-impact causes such as RTA, which as a mechanism of injury was low in our study.

When observing injuries sustained in urban or rural environments, patients had the same average age and injuries more commonly acquired as a result of interpersonal violence. A disparity existed between site of injury with nasal bone fractures occurring more common in urban settings and zygomatic fractures in more rural areas. These findings are similar to that of Batista et al., who found the same fracture presentation comparing urban and rural patient cohorts in a Brazilian population [19].

This study had several limitations; first being its retrospective nature which limited the scope of the data available from hospital records and patient charts. The size of the study population was also small with some nationalities underrepresented. There may also be some discrepancy where some patients identified as Irish but did not hold either an Irish passport or Irish citizenship.