Polarized Light Microscopy
Micrographs of OGs were obtained on an Axio-Lab A.1 polarized light filter optical microscope (Zeiss, Jena, Germany) equipped with an Axio-Cam ERc 5S digital camera. The image set was processed with ZEN 2.3 lite software (Blue edition, Zeiss, Jena, Germany). From the obtained micrographs, a grayscale image analysis was performed by the FDim software of Martin Reuter (MIT-Cambridge, MA, USA) to obtain the fractal dimension (FD) values, where the best FD value was selected according to the obtained correlation coefficients.