抄録
Due to the physiological changes associated with aging and jawbone changes, including tooth loss in the maxillofacial region, differences in trauma are expected between elderly and nonelderly individuals. This study compared mandibular fractures due to falls between these groups.
We retrospectively evaluated 155 patients with mandibular fractures due to falls who visited our department, and categorized them into the elderly （above 65 years old） group and the nonelderly （below 65 years old） group.
There were 81 nonelderly and 74 elderly patients. The male : female ratio was 2.5：1 and 1.1：1 in the nonelderly and elderly groups, respectively, with a small gender difference in the latter. The risk factors identified for falls were pre-existing diseases （nonelderly, 36％; elderly, 88％）, alcohol consumption （nonelderly, 37％; elderly, 8％）, and loss of consciousness （nonelderly, 51％; elderly, 20％）. The most common fracture site was the condylar process in the nonelderly （58％） and elderly （71％）. Condylar process fractures were more common in the nonelderly patients because more than half of the injuries were caused by loss of consciousness or alcohol consumption, and in the elderly patients because of loss of buffering of external forces by the tooth due to tooth loss. Analysis using the Eichner index revealed that 1） the body of the bone in group A and the articular process in groups B and C were the common fracture sites; 2） common fracture site in the articular process was the basal part in group A and the superior neck in group C; and 3） the common fracture aspect of the articular process was fissure in group A and dislocation in group C. The Eichner index suggested an association between occlusal support and fracture pattern.
Mandibular fractures in elderly patients due to falls exhibited differences in fracture status due to the general and local physical changes unique to this population group. Evaluation using the Eichner index revealed an association between loss of occlusal support and mandibular fracture pattern.
