Septal Cartilage Defined In Chinese:Measurements On Cadaver Samples,Intraoperatively Harvested Grafts And 3D CT Reconstructive Images

Objective 1.To determine the dorsal length and caudal length of septal cartilage and thickness at specific site by direct measurement.To measure the area of total septal cartilage and harvestable cartilage preserving a 10 mm L-shape strut using a software.To measure the angle between septal cartilage and upper lateral cartilage and analyze the thickness of sepatl cartilage using CT scanning data and 3D reconstructive images.2.To develop an optimal 3D reconstruction and measurement method based on head CT scanning data which can be used for patients with septum deviation.3.To evaluate the effectiveness of CT 3D reconstruction and measurement method by comparing the results between directly intraoperative measurements and CT 3D reconstruction and measurements.4.To compare the size of septal cartilage between Chinese and other ethnic populations which were reported inliteratures.Methods 1.Directly measure the dimensions of septum and upper lateratl cartilage using samples harvested in cadaver anatomy,then analysis the thickness of the cartilage using CT scanning data.2.Get the CT scanning data of patient' s head.Then combine the 3D reconstructed image of bony septum with selected saggital plane.Define the optimal reconstruction meothd by comparing the total septal cartilage area calculated from different methods.3.Measure the dimensions of septal cartilage harvested in extracorporeal septoplasty.Calculate the area of septal cartilage using CT 3D reconstruction and measurement.Then evaluate the reliability of CT reconstruction and measurement method.4.Compare the area of septal cartilage between Chinese population which is calculated intraoperatively and other ethnic populations which can be extracted from literatures.Results 1.The total septal cartilage area measured on cadaver samples is 612.4±130.9mm2 and the harvestable septal cartilage area is 253.5±75.06mm2.The thickness analysis shows that the septal cartilage is thicker in the the central area and thinner on the anterior septal angle.The thickness of L-shape struct is uneven but generally thinner than the central area.The area of septal cartilage reconstructed on sagittal image crossing the nasal tip is larger than that crossing the anterior nasal spine.The difference is statistically significant(p<0.05).3.The total septal cartilage harvested in the operation is 613.8 ± 114.8mm2.The harvestabel septal cartilage preserving a 10mm L-shape strut is 282.7±76.86mm2.The difference of total septal cartilage calculated between the two methods is statistically significant(p<0.05).4.The areas of total septal cartilage and harvestable cartilage vary a lot in literature.The total septal cartilage area measured in this study is equivalent to that reported by Jun Sik Kim(p=0.81),and is significantly different from the areas reported in other literatures(p<0.05).The harvestable septal cartilage measured in this study is significantly different from those reported in the literature(p<0.05).Conclusion 1.The harvestable septal cartilage area preserving a 10mm L-shape strut is 253.5mm2,the dorsal length and caudal length are both about 15mm.Cartilage of this size is not capable of being used as coloumellar strut.The thickness of septal cartilage is thicker in the central area and thinner on anterior sepatal angle.The L-shape strut is relatively thin.So the width of L-shape strut should be properly preserved.2.The reconstructive image combined by bony septum image and sagittal image crossing the nasal tip could be used to determine the border of septal cartilage.This method could be used to evaluate patients with septal deviation.The preoperative evaluation and estimation of setal cartliage area can be more accurate.The sagittal image crossing nasaltip combined with bony septum yields largest septal area.3.The shape of septal cartilage on 3D CT reconstructive image matches that of the septal cartilage harvested in the operation.The harvestable septal cargilage area calculated on 3D CT image can be well used to evaluate the size of intraoperative harvestable septal cartilage.4.The dimensions of septal cartilage vary greatly between ethnicities.The sepatl cartilage in Chinese is smaller than that in Caucasian and Indian and also smaller than most Korean measurements.More studies are needed to determine the more acurate anatomic characteristcis of septal cartilage.