What exactly are the teeth on the nails? First of all, most of the nail is composed of keratin, which is also a type of protein and is synthesized from various amino acids, just like other proteins in the body. The nail bed is rich in capillaries, hence the pinkish appearance of the nail. Immature nail cells look white. As the nail cells grow and push forward and outward, the nail cells become harder and clearer. A division is formed between the mature and immature nail cells, thus forming what is known as a crescent, or in more technical terms, a nail half-moon. The more the healthier? As long as there are nails, there will be crescents, only invisible crescents, no non-existent crescents. Whether or not you can see the crescent with the naked eye, and the size of the crescent, depends on the location of the mature finger. Nails that are used a lot are stimulated more and grow faster, and the crescent can be easily pushed out. This explains why most people have crescents on their thumbs, while the pinky finger is less used and less stimulated than the other four fingers, so the growth of the pinky nail is slower than the other four fingers, so crescents on the pinky finger are less common. If you play the piano a lot and use your pinky finger more frequently, the growth rate of your pinky finger nails will accelerate, so the crescent will also emerge, so there is no scientific basis for judging health by whether you can see the finger crescent or how many crescents, but you can judge the frequency of their finger use. Fullness means health? Due to the different speed of cell growth, the middle one grows faster, becomes transparent and hard but does not change depending on its location, so the shape of the crescent is usually half-moon. In general, the shape of the finger crescent is half-moon, but it is not that the crescent is not full is unhealthy, this is completely unfounded. It is believed that the general public only uses this statement as a kind of gossip, without much practical significance. Does the state of the crescent have anything to do with it? Whether there are 10 crescent teeth or only 1 or 2, and whether they are “full” or only “shyly” showing a little, as long as there is no significant change in size or number, it is normal and not something to worry about.