Trends and characteristics of facial injuries in New Zealand: Insights from a cohort study

Background Facial injuries are associated with significant morbidity and healthcare costs, yet data across all severity levels remain limited. This study aimed to examine demographics, incidence, injury characteristics, and outcomes of patients admitted with facial trauma across all age groups and injury severity in a health region of one million residents in New Zealand (NZ). Methods A retrospective analysis of admissions with traumatic facial injuries across the Te Manawa Taki (TMT) region from 1 January 2014 to 31 December 2023, using data from the TMT Trauma Registry, was conducted. Injuries were classified using the Abbreviated Injury Scale (AIS), Injury Severity Score (ISS), and ICD-10-AM codes. Population-adjusted incidence rate ratios (aIRRs), corrected for age, gender, and ethnicity, were calculated. Results A total of 4,020 facial injury incidents were documented. Māori individuals (65.9/100,000; aIRR 2.1, p < 0.001) and males (57.8/100,000; aIRR 2.3, p < 0.001) exhibited significantly higher rates compared to non-Māori (32.2/100,000) and females (25.3/100,000), respectively. Most injuries were of low severity (ISS 1–8; 82.5%), with blunt trauma representing 96.1%. Falls (27.4%) and assaults (26.7%) were the primary causes of mild injuries, while road traffic crashes and assaults were more common in moderate and severe cases. Mandible fractures (15.6%) and soft tissue injuries were the most frequent. The average hospital stay was 3.2 days (SD 4.7), and the case fatality rate was 0.7% ( n = 27). Conclusion This study provides a comprehensive analysis of facial trauma in NZ, incorporating all ages and injury severities. Facial injuries impose a substantial burden in the TMT region, disproportionately affecting people of Māori ethnicity and males.