Exploring objects with the mouth (orofacial exploration disorder) is seen in Alzheimer’s disease dementia. Alzheimer’s disease dementia used to be called progeria for those who developed it before the age of 65, and senile dementia for those who developed it after the age of 65. What are the causes of Alzheimer’s disease dementia? 1. Family history The vast majority of epidemiological studies have suggested that family history is a risk factor. Some patients have a higher risk of having family members with the same disease than the general population, and an increased risk of congenital stupidity has also been found. Further genetic studies have confirmed that the disease may be due to autosomal dominant genes. Some physical diseases such as thyroid disease, immune system disorders, epilepsy, migraine, etc. have been studied as risk factors for AD. The relative risk of AD is 2.3 for those with a history of hypothyroidism and 1.6 for those with a history of epileptic seizures before the onset of the disease. A history of migraine or severe headache was not associated. Many studies have found that a history of depression, especially in old age, is a risk factor. 3. Education level There are increasing reports that low education levels are associated with an increased prevalence of dementia. In Shanghai, the prevalence of dementia and Alzheimer’s disease was reported to be 6.9% for illiterates and 1.2% for those with more than 6 years of schooling. A recent Italian epidemiological survey had similar findings. A Japanese case-control study, however, did not find an association between education level and dementia and/or dementia subtypes. 4, Head trauma Head trauma refers to head trauma with impaired consciousness. Traumatic brain injury has been more frequently reported as a risk factor for Alzheimer’s disease dementia. 5. High or low maternal reproductive age (>40 years or <20 years) Since congenital dysmorphism may be a risk factor for Alzheimer's disease, the risk of DS increases with maternal reproductive age.