The phenomenon of “long” wisdom teeth at the age of 40 is usually caused by the complete ambulation of wisdom teeth. Wisdom teeth are the third molar of human beings. The embryo of wisdom teeth usually forms at the age of 4~5 years after birth, and normally grows at the age of 16~25 years. However, with the refinement of diet, the jawbone begins to deteriorate, which results in the amount of teeth being larger than the amount of bone, and the final eruption of the wisdom teeth does not have a gap, resulting in the partial eruption of wisdom teeth, or complete ambulatory obstruction of the wisdom teeth. Many people do not have any symptoms because their wisdom teeth are completely submerged and blocked, and they usually do not know that they have wisdom teeth if they do not take a picture of them. As they grow older, some of the teeth in their mouths will be missing and the jawbone will gradually appear to have gaps, which will provide conditions for the eruption of the wisdom teeth, and that is why there is the phenomenon of wisdom teeth at the age of 40 years old. If you have any problems with your wisdom teeth, you should seek medical attention in a timely manner.