Trends in mandibular fractures in the USA: A 20-year retrospective analysis

Abstract

Background/aim: The mandible is one of the most fractured bones in the maxillofacial region. This study analyzes trends in mandibular fracture patterns, demographics, and mechanisms since the early 2000s.

Material and methods: Mandibular fractures were reviewed from the 2007, 2011, and 2017 National Trauma Data Bank including 13,142, 17,057, and 20,391 patients by year, respectively. This database contains hundreds of thousands of patients annually and represents the largest trauma registry in the United States. Variables included number of fractures, sex, age, injury mechanism, and fracture location. Mechanism of injury included assault, motor vehicle crash, fall, motorcycle, bicycle, pedestrian, and firearm. Anatomic locations based on ICD-9/10 codes included symphysis, ramus, condyle, condylar process, body, angle, and coronoid process. Frequencies were compared using Chi-square tests of homogeneity with effect sizes estimated using Cramer's V.

Results: Mandibular fractures represent 2%-2.5% of all traumas reported in the database from 2001 to 2017. The proportion of patients sustaining a single reported mandibular fracture decreased from 82% in 2007 to 63% in 2017. Males consistently experienced 78%-80% of fractures. Eighteen to 54-year-olds experienced the largest percentages of fractures throughout the 21st century, while median age of fracture shifted from 28 to 32 between 2007 and 2017. The most common fracture mechanisms were assault (42% [2001-2005]-37% [2017]), motor vehicle crash (31%-22%) followed by falls (15%-20%). From 2001-2005 to 2017, a decrease was observed in assaults (-5%) and motor vehicle crash (-9%) and an increase in falls (+5%), particularly among elderly females. The mandibular body, condyle, angle, and symphysis represent approximately two-thirds of all fractures without a consistent temporal trend among them.

Conclusions: The temporal trends observed can be linked to shifting age demographics nationally that may aid clinicians in diagnosis and inform public safety policies aimed at reducing these injuries, particularly among the growing elderly population.

Keywords: age-related; epidemiology; mandible fractures; national trends.