Wisdom teeth that do not erupt. If a wisdom tooth does not erupt, the remaining tooth germ may degenerate and form an oral tumor. The germ may absorb the roots of the second molars in front of the tooth when there is not enough space, which may reduce the strength and affect its function. Incomplete eruption of wisdom teeth. The gum on the posterior side of the wisdom tooth is not fully developed and covers part of its crown to form a pericoronal pocket, which accumulates food and bacteria and can cause frequent inflammation of the local soft tissues and pain, even leading to restricted opening and difficulty in eating. Some people are reluctant to remove them after the inflammation has subsided, no more pain, and they are able to eat, and as a result, they become inflamed again and the symptoms become more serious. Anteriorly inclined wisdom teeth. Most of the wisdom teeth are on the front normal molars at an angle of about 45 degrees, and the two crowns form an angle to embed food, which will cause the normal second molars to form caries and pulpitis and severe pain after a long time. Another consequence is that the anteriorly tilted wisdom teeth continue to exert force on the second molar, causing periodontitis and painful loosening, and finally the second molar has to be extracted, or the two teeth have to be extracted, and the chewing function is seriously damaged. Although the eruption direction of some wisdom teeth is more or less normal, the contact point with the second molar is not normal, and the gap is large, so that the food is often embedded, and it is not easy to brush the gap when brushing, and it is very easy to cause the second molar caries and shorten its service life. Wisdom tooth pericoronitis occurs. The surface of wisdom tooth is covered by gum flap, so that a gap is formed between it and the crown, which is called blind pocket in medical science. The food residues people eat are most easily hidden in it, plus the humidity and moisture of the mouth is suitable, which provides a good environment for bacteria to grow and reproduce. The food residue in the blind pocket is not easy to remove even if you brush and rinse your teeth. Under normal circumstances, the harm caused by bacteria is not obvious, but in the cold, fatigue, resistance to reduce, it will rise, take advantage of the situation, which formed the wisdom teeth pericoronitis. This disease should not be underestimated. It comes on fiercely, with painful swelling of the gums, and in severe cases, there will be tightening of the teeth, difficulty in eating and swallowing, and accompanied by systemic symptoms such as fever, headache, peripheral discomfort, constipation, and increased white blood cells. If treatment is not complete, it will become chronic inflammation. When pericoronitis recurs, the pus in the blind pocket enters the digestive tract from the oral cavity and can form a “lesion” in the body, which can be a long-term health hazard. Wisdom tooth pericoronitis can also cause facial soft tissue infection and spread to the head and face causing adverse consequences.