Many people do not realize that dentures need to be replaced. Many people think that even if I am comfortable with them, do I need to replace them? I would say that you are “comfortable” with them, but the teeth may not fit you anymore. So what kind of teeth need to be replaced? The dentist has some criteria: 1, the vertical distance: that is, the straight line between the upper and lower teeth, in layman’s terms, the distance from the bottom of the nose to the chin, easy mouth closure distance. After several years of using dentures, especially full dentures, the resorption of alveolar bone, tooth surface wear, can cause a change in vertical distance, when this occurs, once accurately embedded intact dentures become loose and unstable. As this phenomenon occurs the loss of vertical dimension is a slow, gradual process and the patient may have gradually adapted to its changing conditions. However, the patient may notice signs of altered (increased) skin folds around the mouth. Also, it may appear that the temporomandibular joint is adversely affected and may become disrupted by the patient’s ability to move the mouth open. 2, Excessive wear of the denture teeth reduces the effective chewing ability. 3, Although the materials used in the production of modern dentures are very durable, but inevitably over time the shape or improperly used parts change and will eventually present dentures do not discomfort need to be replaced. Especially in the case of front teeth, the aging color loses its natural appearance, plus the cleaning adds texture and texture coloring, making the denture appear artificial. Denture plastics deteriorate and may also become overly microbially contaminated. In turn, this may contribute to the irritation of bad taste to the mouth, producing an odor that is socially unacceptable. For oral health, it is essential to maintain regular oral examinations, and regular denture replacement is essential to maintain optimal health of oral soft tissues and to extend jaw life and oral function.