Reduction malarplasty for making an oval facial shape is a popular procedure in Asia. However, a range of complications after malarplasty have been reported, including hematoma, orbital complications, asymmetric face, and depression of the chin. Fixation can be incomplete and the osteotome can penetrate the sinus during surgery due to the narrow surgical field, which can result in sinusitis caused by bony fragments after malarplasty. However, there are no reports of sinusitis caused by bony fragments after malarplasty. The authors report 2 cases of chronic sinusitis caused by displaced bony fragments after reduction malarplasty.