أرسل هذا في رسالة قصيرة: Optical Microscopic Images of Ghost Aligner at different Tooth Positions: (a) First Molar on the Upper Right showing Crack Formation; (b) Second Molar on the Upper Right showing Wider Cracks; (c) Second Premolar on the Upper Right Showing Strain Hardened Regions and Cracks; (d) Second Premolar on the Upper Left Showing Strain Hardened Regions.