Wisdom teeth often do not have enough room to erupt because modern human beings have a smaller jawbone. This causes wisdom teeth to grow slanted, horizontally, or even to be completely buried inside the jawbone.
– Tooth decay
Since it is difficult to clean the surfaces between the impacted tooth and the adjacent tooth in front, dental plaque will accumulate there and cause tooth decay on these tooth surfaces.
Photograph of an impacted wisdom tooth growing slanted towards its adjacent tooth. The adjacent surfaces of the teeth are decayed.