You will need a mirror, a tape measure or ruler with metric markings, a pen, and some paper. This process will be easier with a fixed mirror rather than a handheld one. You can also ask a friend to help if you are comfortable doing so. Look into the mirror and identify the teeth that have gaps in between them. Make notes about the appearance of your gaps and why you would like to fix them. Also make notes on any other imperfections that you would like to fix along with your gaps (tooth size, color, straightness, chips, etc.). Using the tape measure or ruler, measure the space in between your teeth that have gaps. Write down the measurements in millimeters. These measurements and appearance notes will help you to determine what dental treatment will benefit you the most. The imperfections that you have identified will also help you dentist when deciding on your best treatment option.

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Write a summary of the previous text in Chinese:
准备工具。 检查牙齿。 测量牙缝。 保存自己的记录。