The patient was a 70-year-old man. He was injured in a motorcycle accident and was brought to the hospital suffering from pulmonary contusions, multiple rib fractures, and a dislocation fracture of the left hip joint. Mechanical ventilation and tracheostomy were performed because of decreased oxygenation. As dysphagia and gait disturbance persisted even after his respiratory condition improved, the patient was transferred to our institution for rehabilitation 63 days after the injury. Rehabilitative intervention for the patient's physical impairments progressed smoothly, and the patient regained independence in activities of daily living. However, 1 week before his scheduled date of discharge, the patient suffered from sudden heart failure at 168 days after the initial injury. Traumatic aortic regurgitation was diagnosed based on the following findings : aortic regurgitation rapidly exacerbated after heart failure, no medical history of heart disease, and no other cause for aortic regurgitation. Surgical treatment with aortic valve replacement was performed. Postoperative recovery was favorable, and the patient was discharged to his home after regaining independence in activities of daily living. Traumatic aortic regurgitation is rare, and patients with this disease often suffer heart failure from a few days to several years after injury. This condition needs to be kept in mind during the rehabilitation process following chest trauma.

Purpose: Deproteinized bovine bone or synthetic hydroxyapatite are 2 prevalent bone grafting materials used in the clinical treatment of peri-implant bone defects. However, the differences in bone formation among these materials remain unclear. This study evaluated osteogenesis kinetics in peri-implant defects using 2 types of deproteinized bovine bone (Bio-Oss ® and Bio-Oss/Collagen ® ) and 2 types of synthetic hydroxyapatite (Apaceram-AX ® and Refit ® ). We considered factors including newly generated bone volume; bone, osteoid, and material occupancy; and bone-to-implant contact. Methods: A beagle model with a mandibular defect was created by extracting the bilateral mandibular third and fourth premolars. Simultaneously, an implant was inserted into the defect, and the space between the implant and the surrounding bone walls was filled with BioOss, Bio-Oss/Collagen, Apaceram-AX, Refit, or autologous bone. Micro-computed tomography and histological analyses were conducted at 3 and 6 months postoperatively (Refit and autologous bone were not included at the 6-month time point due to their rapid absorption). Results: All materials demonstrated excellent biocompatibility and osteoconductivity. At 3 months, Bio-Oss and Apaceram-AX exhibited significantly greater volumes of formation than the other materials, with Bio-Oss having a marginally higher amount. However, this outcome was reversed at 6 months, with no significant difference between the 2 materials at either time point. Apaceram-AX displayed notably slower bioresorption and the largest quantity of residual material at both time points. In contrast, Refit had significantly greater bioresorption, with complete resorption and rapid maturation involving cortical bone formation at the crest at 3 months, Refit demonstrated the highest mineralized tissue and osteoid occupancy after 3 months, albeit without statistical significance. Conclusions Overall, the materials demonstrated varying post-implantation behaviors in vivo. Thus, in a clinical setting, both the properties of these materials and the specific conditions of the defects needing reinforcement should be considered to identify the most suitable material.