Implication of differences in the incidence of orbital emphysema in ethmoidal and maxillary sinus fractures

This study investigated the incidence of orbital emphysema in patients with fractures of the ethmoidal cells or maxillary sinus. We noted that mucosal destruction is essential for orbital emphysema to occur. Computed tomographic examination and intraoperative studies of 58 patients with orbital bone fracture were performed with the patients divided into 2 groups according to the location of the fracture lines. The incidences of orbital emphysema and of intrasinus hematoma were significantly higher in the group with medial orbital bone fracture of ethmoidal cells than in the group with maxillary sinus fracture, which indicates mucosal tear was significantly higher in the former group. Fractured lamina papyracea and intrasinus hematoma were observed in all cases with ethmoidal sinus fracture. On the other hand, intrasinus hematoma was not found in some cases with maxillary sinus fracture, blowout fracture of the orbital floor, or zygomatic bone fracture, while all cases with orbital emphysema were included in the cases with intrasinus hematoma. This suggests that the incidence of orbital emphysema depends on the occurrence of tearing of the mucosa of the paranasal sinus.