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BACKGROUND The septal extension graft (SEG) has become the preferred augmentation rhinoplasty technique in Asia for its superiority in correcting tip projection and rotation. OBJECTIVES The author sought to build a rabbit model for SEG surgery and compared the postoperative stability of the tip support between the bilateral batten costal and conchal cartilage extension grafts at the nasal tip. METHODS Twenty rabbits underwent SEG surgery with either bilateral batten costal cartilage graft (Group A) or bilateral batten conchal cartilage graft (Group B). Serial photographs were obtained to evaluate the change of the nasal tip shape and graft shape. The observed indices include tip projection, tip angle, shape of extension graft, and histological features of the extension graft. RESULTS Twelve weeks after the operation, one costal extension graft in group A (1/10) and three conchal extension grafts in group B (3/10) were reabsorbed. The costal cartilage graft showed better exterior results than conchal cartilage graft in terms of tip projection and angle relapse rate (13.01% vs. 25.02% and 15.18% vs. 28.73%, p < 0.05). The costal cartilage graft maintains its structure more than the conchal cartilage graft. A greater degree of calcification and more fibrous capsules around the extension graft were found in Group A. CONCLUSIONS A rhinoplasty rabbit model was established to compare costal and conchal autologous cartilages for SEG. Additionally, this model may serve as a training tool for rhinoplasty surgeons. The costal cartilage extension graft is more reliable in terms of stability and may be paid more attention.