Gaps in the incisors in the forties and fifties may be due to physiological reasons or pathological reasons, such as periodontitis, caries and other causes. 1. Physiological reasons: when the number of teeth is less than the amount of bone, there will naturally be gaps between the teeth. Some people have larger jaws and are born with smaller teeth. It is normal for every tooth to have a gap. 2. Pathologic causes: (1) Periodontitis: patients will experience gum recession and resorption of the alveolar bone, causing gaps in the neck of the tooth or even root exposure. (2) Caries: the area adjacent to two teeth is the most difficult position to clean, causing bacteria to multiply and the dentition to be destroyed. This causes caries on the neighboring surfaces, resulting in gaps on the neighboring surfaces of the incisors. When the gap between incisors is large in the age of forty or fifty, accompanied by symptoms of discomfort. It is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, and targeted treatment or treatment.