lower tooth

It is done so that the upper tooth grows healthy downwards, while the lower tooth upwards.

这样是为了让上牙向下长，下牙向上长。

Steel tooth bit can increase the bit's stability and lower the tooth impact load, and enhance its wear resistance.

钢齿牙轮钻头增强了工作的平稳性，降低了牙齿的冲击载荷，使牙轮钻头的耐磨性能得到提高；

The results show that in the case of the same cutting resistance, pick-shaped teeth enjoys advantages over knife-shaped teeth, as a result of it better combined performances, such as freedom of fragment, the lower tooth cost and wear-proof.

结果表明：在截割阻力相同的情况下，镐形齿具有不易被击碎、齿耗低、耐磨等优点，其综合性能优于刀形齿。

If either the number of sun or ring gear is not multiple of planet gear, system will run effectively, with lower impaction of tooth mesh in and out.

行星轮与内齿圈齿数不为行星轮个数的整数被时，轮齿的啮入、啮出对系统的冲击小，系统的效率高。

In Japan, children throw a lower baby tooth up onto the roof so the next tooth grows healthily upwards;

在日本，孩子会把下齿的乳牙放到房顶上，这样的话下颗牙将会长得结结实实；

Japan If it is a lower baby tooth, throw it up onto the roof; and if it is an upper tooth, throw it underneath the 'en-no-shita' ( the lower portion below the floor of a Japanese house).

在日本，如果掉的是下牙，就扔到房顶上去；如果是上牙，就放在外廊地板下面。

The upper and lower jaws possess straight tooth rows and the jaw arches are almost rectangular in shape.

上、下颌具有直的齿列，而颌弓几乎呈直角形。