Investigating the relationship between psychophysiological parameters and behavioral patterns in children aged 7-10 years during dental treatment.

Manganese (Mn) is an essential trace element involved in amino acid, cholesterol, glucose, and carbohydrate metabolism; reactive oxygen species scavenging; bone formation; reproduction; and immune response []. Excessive exposure to Mn, either through occupational, environmental, or diet may result in neurotoxicity. Excess Mn accumulates in the basal ganglia, especially in the striatum, globus pallidus (GP) and substantia nigra (SN). Case reports describing Mn toxicity in humans date back to 1837, when a clinical syndrome of Mn neurotoxicity, currently known as “manganism”, was described for the first time in workers with excessive occupational exposure to air-borne Mn []. Mn exposure has been associated with reduced performance on neuropsychological testing, poor eye-hand coordination and hand steadiness, reduced reaction time, reduced cognitive flexibility, and poor postural stability []. Mn toxicity has been shown to occur in certain occupational settings through inhalation of manganese-containing dust []. High Mn occupational exposure has been linked with motor, behavioral and cognitive impairment []. Manganism is a syndrome similar to Parkinson’s Disease (PD), characterized by psychiatric and cognitive deficits and motor impairment []. Welders exposed to manganese-containing fumes have a significantly higher risk of developing parkinsonian symptoms compared to non-welders []. A pilot study of farmworkers in Costa Rica however did not find strong evidence that Mn concentrations were associated with working memory-related brain activity in this sample of farmworkers []. While significant research has focused on heavy metal neurotoxicity in occupational settings, including narrative reviews of manganese mining exposures and neurologic toxicity in occupational cohorts [], population-level epidemiological evidence on low-level environmental exposure and cognitive function remains limited. Contaminated air or water poses a risk of Mn intoxication to the general population. Mn exposure from environmental sources has been associated with a higher prevalence of Parkinsonian disturbances []. Environmental Mn exposure was found to be associated with lower performance on neuropsychological tests measuring a variety of cognitive functions, including significant associations between Mn exposure and cognitive function obtained in the domains of visuospatial memory and verbal skills []. The presence of excessive Mn levels in drinking water has been associated with poorer memory and attention and hyperactive behavior in school-aged children. Consumption of water containing elevated Mn levels had adverse effects on 10-year-old children’s cognitive function [].