Fig.8.

Schematic to show the cascade from tooth loss to the progression of Alzheimer’s disease via the trigeminal mesencephalic nucleus, locus coeruleus, and hippocampus. Aging leads to increase the intracellular Aβ accumulation in trigeminal mesencephalic nucleus (Vmes) neurons, and tooth loss leads to Vmes neuronal death. Release of Aβ by Vmes neuronal death causes neurodegeneration of adjacent locus coeruleus (LC) neurons, resulting in neuronal degeneration of hippocampal neurons that the LC neurons project. This neurodegenerative cascade of Vmes, LC and hippocampus accelerates the progression of Alzheimer’s disease.