# Collecting file directories into a dictionary
oral_disease_file_names_dict = {}

for img_dir in img_dirs:
    disease_name = img_dir.split('/')[-1]
    oral_disease_file_names_dict[disease_name] = []
    for root, dirs, files in os.walk(img_dir):
        for file in files:
            if file.endswith(('.jpg', '.jpeg', '.png', '.bmp', '.gif')): 
                file_path = os.path.join(root, file)
                oral_disease_file_names_dict[disease_name].append(file_path)