• pupil size
• locus coeruleus
• HRV
• cognitive performance
• sleep

As a consequence of the worldwide aging populations, the amount of people with dementia is rapidly increasing. Besides aging, other risk factors, potentially modifiable, have been identified for cognitive impairment, including masticatory dysfunction and sleep disturbances. In order to find out preventive measures useful for delaying the onset - and possibly reverting – the cognitive impairment, two main different studies were conducted.
Regarding the masticatory dysfunction, recent evidence shows how unilateral molar loss condition, characterized by an unbalanced trigeminal input from the oral cavity to the brain, results in an asymmetric right-left activation of the Locus Coeruleus (LC), the main noradrenergic nucleus present in the brainstem, which may lead to cognitive impairment. Conversely, the rebalancing of the trigeminal afferents with appropriate oral implant-prosthesis decreases the asymmetry in LC activity and improves cognitive functions. In the attempt to shade light and further understand the link between trigeminal afferents and higher brain functions, the present studies investigated how trigeminal information may affect the neuromodulatory brain system and its related structures and the cerebral activity.
Moreover, regarding the sleep disturbances, studies were conducted to understand the possibility to predict sleep parameters on the basis of the Heart Rate Variability (HRV) metrics characteristic of the pre-sleep onset period.
Findings suggest the possibility a) to revert the cognitive impairment after masticatory unbalance correction and b) to predict the sleep parameters from HRV metrics.