Whether or not the innermost teeth of the upper jaw are easy to extract is related to the oral conditions and the growth of the teeth. It is generally more difficult to extract the teeth if the mouth opening is small and the teeth are in an obstructed state. The inner most teeth of the upper jaw are often the third permanent molars, also known as wisdom teeth, which have the greatest variation in morphology in the oral cavity, and may be low or proximal to the middle of the obstruction, and there is often resistance from bone and soft tissues when extracting the teeth, and the difficulty of extraction is exacerbated by the small opening of the mouth. If the wisdom tooth is congenitally missing, the innermost tooth in the upper jaw is usually the second permanent molar, which is moderately difficult to extract due to its usually orthodox growth position, but specific radiographic examination is required. Whether or not it is a good idea to extract the innermost tooth of the upper jaw can only be determined after an oral examination and X-ray at the hospital.