Predictive Evaluation of Septal Cartilage-bone Complex for Rhinoplasty Using Cone Beam Computed Tomography

Background:Septal extension grafting (SEG) is commonly used for correcting Asian short noses. When septal cartilage is limited, septal bone can be included. This study evaluates the outcomes of SEG using a septal cartilage-septal bone complex (SCBC) and assesses preoperative cone beam computed tomography (CBCT) for predicting septal bone suitability.Methods:A retrospective review was conducted of Korean women planned for SEG with SCBC from July 2021 to June 2022. Preoperative CBCT scans measured Hounsfield Unit (HU) values for septal cartilage, perpendicular plate of the ethmoid (PPE), and vomer. Of 27 patients, 19 underwent SEG with SCBC, whereas 8 did not due to unsuitable septal bone. Clinical outcomes and satisfaction were assessed through surveys and photographs.Results:For the 19 patients using SCBC, the average HU for PPE was 286.5 +/- 126.6 (ratio 6.8 +/- 2.1), and for vomer, HU was 230.3 +/- 95.2 (ratio 5.7 +/- 1.8). SEG significantly improved nasal length and tip projection, although tip softness was less favorable. Among the 8 patients not using SCBC, 5 had bones that were too thick and stiff (PPE: 667.8 +/- 102.2, ratio 15.5 +/- 2.7; vomer: 342.8 +/- 55.1, ratio 8.1 +/- 2.3), and 3 had fragile bones (PPE: 148.7 +/- 45.4, ratio 3.1 +/- 0.7; vomer: 199.0 +/- 68.6, ratio 4.1 +/- 0.9).Conclusions:SEG using SCBC effectively corrects short noses in Asian patients. Preoperative HU ratios from CBCT can help predict septal bone quality and guide surgical planning. Further research with larger cohorts is needed to confirm these findings.