CLINICAL SIGNIFICANCE CONCLUSIONS and FUTURE DIRECTIONS The Depths of Commonly Grafted Costal Cartilages for Use in Facial Reconstructive Surgery Hannah Lynch1, A Bender-Heine2, JS Holmes3, A Rickards3, H Wayne Lambert3, MJ Zdilla1,4 1Dept. of Natural Sciences & Mathematics, West Liberty University, West Liberty, WV 2Dept. of Otolaryngology, West Virginia University School of Medicine, Morgantown, WV  3Dept. of Neurobiology & Anatomy, West Virginia University School of Medicine, Morgantown, WV  4Dept. of Graduate Health Sciences, West Liberty University, West Liberty, WV METHODS ABSTRACT CLINICAL SIGNIFICANCE Cadaveric anatomical study was performed with the permission of the West Virginia Anatomical Board. Sixteen cadavers, ranging in age from 35- to 99- years old, were dissected with the intent of exposing the 5th, 6th, 7th, and 8th costal cartilages along with the sternum and the ribs (Figure 2). Eleven of the sixteen rib cages belonged to males while the other five were females. Measurements were taken of the costal cartilages with ImageJ software. Each costal cartilage was investigated with medial, intermediate, and lateral approaches (Figure 3). Use of costal cartilage for facial reconstructive surgery is widely utilized, but despite the popularity and success rates associated with the procedure, there has been no prior research performed indicating the most sufficient costal cartilage to target. Likewise, graft structures are diverse (Figure 5). This research provides measurements of the most commonly utilized costal cartilages, for the benefit of improved presurgical planning in order to improve clinical outcomes. Although there are variations in size among the population, the research indicates basic trends that would assist in the selection of optimal cartilage for harvesting. Reconstructive surgery commonly employs grafted costal cartilages, but the appropriate cartilage to select is often a question of the volume of material necessary to shape the graft. However, there is little information regarding the depth (superficial-to-deep) of commonly grafted costal cartilages. Therefore, this cadaveric study sought to determine the average depth of the 5th, 6th, 7th, and 8th costal cartilages since these are the most commonly grafted cartilages. The cartilages were analyzed from medial, lateral, and intermediate locations, revealing that the thickest cartilage is found at the medial portion of the 6th cartilage while the thinnest cartilage is found at the medial aspect of the 8th cartilage. Average depth did not differ between cartilages near each respective rib, but the average thickness differed greatly near the sternum. Results support the assumption that any location along the 6th costal cartilage has, on average, a greater depth than any part of the 5th, 7th, or 8th cartilages. BACKGROUND Recent information has noted that West Virginia has the highest death rate due to drug overdose nationwide with a rate of about 34 deaths per 100,000 residents. In the US cocaine is routinely cut with Levamisol, a livestock de-wormer, which has been proven to cause vasculitis, as well as necrotic lesions, especially on the face and limbs. Cocaine can lead to necrosis of the nasal tissues via decreased blood flow. Severe cases of necrosis may lead to the need of reconstructive surgery, as demonstrated in Figure 1 below. Costal cartilage, especially that of the 5th, 6th, 7th, and 8th cartilages, is commonly utilized and has been incredibly successful for use in facial reconstructive surgery and more specifically nasal reconstruction. Figure 2. The 5th, 6th, 7th, and 8th costal cartilages are numbered on a cadaveric ribcage used in this study. Figure 3. The medial, intermediate, and lateral aspects of the 6th costal cartilage are displayed on the diagram. RESULTS Figure 5. Costal cartilage has proven to be particularly useful in nasal and facial reconstruction. (d) displays costal cartilage components that have been harvested and carved to match the various regions of the nose. CONCLUSIONS and FUTURE DIRECTIONS The costal cartilage that proved to consistently provide the greatest depth for use in facial reconstructive surgery is found at the 6th position as shown in Figure 4. The medial aspect of the 5th, 6th, and 7th cartilages provides increased depth over the intermediate or lateral aspects. The lateral aspect of the 8th costal cartilage shows the greatest depth. The greatest depth measurement is found at the medial aspect of the 6th costal cartilage. These results are particularly helpful for West Virginians who are suffering from the physically deforming effects of drug use. More research is being conducted regarding cartilage shape and the deformation of harvested cartilage over time. Figure 1. Frontal and lateral views of a patient suffering from leukocytoclastic vasculitis with necrotic lesions on the nose and facial area. The wounds on this 44 year old woman’s face are the result of long term cocaine use, which includes Levamisol as an ingredient. Due to the extensiveness of the injuries, the tip of the nose has undergone self-amputation. Necrosis can be also be seen on the ears, face, and nose. Reconstruction of the nose would involve the columella, dorsum, tip, and parts of the alae and nostrils on both sides. ACKNOWLEDGEMENTS The authors would like to acknowledge the West Virginia Anatomical Board, the WVU Human Gift Registry, and most importantly those individuals who gifted their bodies for the advancement of science and education, without whom, this research would not have been possible. OBJECTIVES Figure 4. Mean depth measurements attained from lateral, middle, and medial of the 5th, 6th, 7th, and 8th costal cartilages is shown in the diagram above. On average, medial depth gives the largest measurement with the exception of the 8th costal cartilage which achieved maximum depth at the lateral aspect. This study sought to discover the most optimal costal cartilage to use in regards to depth for use in facial reconstructive surgery.