Based on this experiment, we hypothesized that occlusal support loss due to tooth loss may cause cognitive dysfunction by promoting mtDNA overaccumulation in the hippocampal region of SAMP8 mice in the Alzheimer’s disease model, up-regulating the cGAS/STING pathway, stimulating downstream immune responses, and triggering microglial cell pyroptosis. This evidence concerns the gene CGAS and early-onset autosomal dominant Alzheimer disease.