Orbital floor fracture (OFF) are frequently associated with zygomatic fractures (ZF). The reduction of the ZF may modify the features of the associated OFF. Intraoperative cone beam CT (CBCT) has shown diagnostic performance of OFF. The aim of our study was to evaluate how intraoperative CBCT control made after the reduction of ZF may help to take a decision on the associated OFF.

Patients with a unilateral displaced ZF associated with an OFF were consecutively included during a 3-year period. Intraoperative CBCT, systematically performed after reduction of the ZF, allowed to decide if the OFF needed reconstruction. The preoperative estimation made on MDCT and the intraoperative decision regarding the OFF were compared.

Fifty-nine consecutive patients could be included in the study. Nineteen OFF were presumed to be surgical indications on the preoperative MDCT but only 16 indications were confirmed on the intraoperative CBCT, meaning that 3 OFF behaved favorably during the ZF reduction. Forty orbital floor fractures were presumed to be non-surgical on the preoperative MDCT but 6 of them worsened during ZF reduction and became surgical indications. Overall, the intraoperative CBCT control had an impact on 9 (15.3%) of the OFF.

Our study showed that OFF after ZF reduction may evolve favorably or, on the contrary, get worse in 15% of the cases. Surgical indication on an OFF can therefore be confirmed intraoperatively. This allows to avoid under-treatment in the patients where the OFF worsens after ZF reduction and over-treatment in the patient where the OFF reduces after ZF.