Anatomical Location of Initial and Repeat Mandible Fractures: A 5-Year, Multi-Institution Retrospective Study

The purpose of the present study was to investigate new fracture patterns resulting from low velocity mechanisms in subjects who had previously fractured their mandible and had been treated with open reduction and internal fixation (ORIF) or closed reduction.

A multi-institutional retrospective cohort study was designed to analyze subjects presenting at 2 tertiary care centers with mandibular fractures with specific interest in subjects who had repeat mandible fractures. Variables recorded included demographic (age, sex, etc) data, fracture location of all fractures treated, and the location of previous fracture. Descriptive and bivariate analyses were completed of the data.

The sample included a total of 492 subjects and 875 total fractures from both institutions. Four hundred fourty-four (91.1%) were male. The average age of all subjects was 36.4 ± 14.9 years. Twenty-six (5.28%) subjects were previously treated for a mandible fracture. All subjects' subsequent fractures occurred outside of previous ORIF except for 1 subject. Original fracture location (P = .596) and previous ORIF type (P = .689) did not influence if the subsequent fracture was within a site of previous ORIF.

The present study demonstrates that repeat mandible fractures are relatively rare, likely to occur only 5% of the time at large tertiary care centers. The repeat fracture is not likely to occur in a site of previous ORIF, regardless of the ORIF modality. Furthermore, the fracture is likely to occur on the contralateral side. This is 1 of the largest data sets on repeat mandible fractures, which, given their rarity, are difficult to study.