The reasons for missing teeth in the elderly group are as follows: 1. As people enter old age, various organs of the human body will experience functional degeneration, and teeth as organs of the human body are no exception. The teeth of elderly patients will generally have weakened tooth structure, and even heavy wear and loosening, which will lead to missing teeth without timely intervention and treatment; 2. Some elderly patients have poor oral maintenance and poor oral hygiene for various reasons, which will lead to periodontal disease, which will lead to further loosening and loss of teeth. Food residues are not thoroughly cleaned and attached around the teeth, which will produce caries and lead to tooth defect too deep and too big, which cannot be repaired and extracted; 3. Some elderly patients have huge biting force and weak tooth structure, so the teeth will split when chewing harder food, which will have to be extracted if they cannot be retained, etc. 4. Poorly designed and made dentures will deteriorate the health condition of the natural teeth of the abutment teeth, and the abutment teeth will be extracted when the dentures are removed 5. Trauma and congenital factors are also common causes of tooth loss.