Differences between Bilateral Costal Cartilage in Patients with Microtia: A Retrospective Study Using Three-Dimensional Imaging.

Costal cartilage is the ideal medium for auricular framework fabrication in auricular reconstruction surgery. Well-developed cartilage is closely associated with surgical outcomes; however, which costal cartilage is better developed and more suitable for framework fabrication is controversial. This study aimed to examine the laterality differences in costal cartilage development in pediatric patients who have undergone auricular reconstruction surgery for microtia. Preoperative thoracic computed tomography data of 101 microtia patients (age range, 6 to 10 years) were retrospectively analyzed. Computer software was used to create three-dimensional costal cartilage images. The length and volume of the costal cartilage of the sixth, seventh, and eighth ribs were measured from these images. Results indicate that the cartilage of the sixth rib on the left side was significantly longer and had a greater volume than that on the right side. Further, the cartilage of the seventh rib on the left side was significantly longer than that on the right side; however, there was no significant difference in volume. No significant differences were found between the cartilage of the eighth rib on the right and left sides. In general, the costal cartilage of ribs on the left side of the thorax was more developed than that on the right. These results may help clinicians in selecting appropriate donor sites before auricular reconstruction surgery in microtia patients.