Prognosis of Performing Split-Rib Bone Graft for Cranial Bone Defects

Background: Frontal sinus anterior wall defects occur because of various diseases, causing not only aesthetic problems, such as forehead bulging and upper eyelid ptosis, but also exerting physical pressure on the brain or optic nerve. Therefore, this study aimed to evaluate the prognosis of performing split-rib bone graft for frontal sinus anterior wall defects. Methods: This study included 30 patients who received a split-rib bone graft for a frontal sinus anterior wall defect. The sizes and volumes of the defects and grafts were measured using three-dimensional computed tomography before, after, and every 6 months for 2 years after the surgery. The Medical Imaging Interaction Toolkit was used for analysis. Results: The average size and volume of the grafts were 27.29 cm² and 5.88 cm³, whereas they were 23.76 cm² and 4.80 cm³ at 24 months after surgery, respectively. In a graft size and volume of less than 27 cm² and 6 cm³, respectively, the rate of graft take was greater than 80% during long-term observation. The younger the age, the higher the rate of graft take. No difference was found in the defect causes. Absorption occurred for up to 18 months. Conclusions: Frontal bone defect reconstruction revealed the stable results of the split-rib bone graft over a long period when the size and volume were less than 27 cm² and 6 cm³, respectively. Furthermore, bone resorption was seen in more than 20% to 30% of the patients, and the rate of resorption increased with age; thus, it is appropriate to consider overcorrection and other reconstruction methods.