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structure of the ECM, multiple-photon laser scanning microscopy has been used for other tissues such as articular cartilage. [190] This method is capable of revealing essential matrix components i.e. chondrocytes, collagen and elastin fibers, label-free, with sub-cellular resolution and deep penetration. [191] The reported stiffness of facial cartilage types varies considerably. Because different techniques are used to measure the cartilage it is difficult to give a general value. Besides tensile or indentation measurements having different limitations and advantages [192], it is also important to discern the different magnitudes or scale of mechanical testing. For the assessment of gross mechanical traits, important for maintaining of large shapes especially in surgical reconstruction, various techniques have been described. [26, 29, 147, 160] The same applies for atomic force microscopy (AFM), where extensive research has been conducted on surface micro mechanics of cartilage. [193-195] However, the mechanical conditions of the scaffold’s cellular environment, between AFM and gross mechanical testing have important influence on the behaviour of cells [196] and as such are fundamental to adequate regeneration of cartilage [158]. Therefore, insight in the local mechanical properties and structure on the ECM level is required to provide the right environment for cell differentiation. The device used in this study allows indentation on the micrometre scale at higher depth ranges providing essential mechanical information on the different cartilage subtypes. Understanding the fundamentals of tissue structures is essential for adequate tissue engineering. From practice, surgeons are familiarized with the gross mechanical traits of cartilage in reconstructive surgery. Mechanical behaviour however is essentially determined on the microscopic scale through an intricate symbiosis of cells and their surrounding structures. In this paper, we aim to provide fundamental information on the differences between the facial cartilage types on a structural and mechanical level with the use of novel technology to evaluate these parameters on the ECM level. Although without direct practical implications, it may also offer surgeons new insights and inspiration in optimizing their reconstructive efforts by providing better understanding on the nature of the tissues they work with. With the advancement of regenerative medicine, surgeons will come to a point where this knowledge will prove invaluable. 46 CHAPTER 3