# Conscious Inhalation Sedation with Nitrous Oxide and Oxygen in Children: A Retrospective Study
## 4 Discussion
No difference was found between females and males, whereas there was a statistically significant difference between the two age groups for the Venham score. Notably, younger children had a higher Venham score from the beginning and maintained these higher scores throughout the dental procedure, although they responded optimally to procedural sedation with N2O/O2. These positive results were also confirmed by the analysis of the Venham score, not only in terms of mean and standard deviation but also as a categorical variable. Indeed, this second analysis showed that the cooperativeness of the younger children increased at the end of the induction phase: The percentage of fully cooperative patients increased from 20.6% to 65.6% and stabilized at 57.3% during treatment. In contrast, the older group had a higher percentage of relaxed children before treatment, which increased and was maintained throughout the dental procedure. The initial difference between younger and older children can be explained as further evidence of the different approach to dental treatment in children of different ages. Although there is no relationship between dental anxiety and fear in the current literature, our study has shown that younger patients approach dental treatments with higher dental anxiety levels: the children appeared tense but not to the point of disrupting the continuity of treatment. A psychometric study conducted in 1997 by [PERSON] et al. on a sample of young American children showed that younger children are more likely to be anxious, especially when the anxiety is a reaction to unfamiliar situations such as those that may occur in a dental office [40]. Previous studies have reported that DFA is higher in younger children [9,10,41,42] and reduces with age [1,2], although the trend of decrease/increase in DFA appears not to be constant throughout childhood. According to [PERSON] and [PERSON], a decrease in DFA was observed in children aged 4-11 years, which increased again after 11 years [43,44], whereas some longitudinal studies showed a different increase in prevalence (from 8.8% at age 5 years to 14.6% at age 9 years or a slight increase of about 3% points from 6 to 8 years) but without a specific trend given that many participants who were anxious at baseline were no longer anxious after 2 years [45]. After the initial anxiety, N2O/O2 therapy showed a positive effect in all patients, especially in the younger ones, reducing the difference between older and younger children in the Venham score. At the end of the treatment, younger children showed some degree of apprehension, although a good level of cooperation was maintained. According to our results, the success rate, i.e., completion of dental treatment, was achieved in over 90% of patients, with a very low rate of side effects, which consisted mainly of nausea, vomiting, headache, and a single case of hyperexcitability. Nausea and vomiting occurred within a few minutes after interruption of dental treatment or after completion of dental treatment. In those cases where interruption of treatment was necessary because of the children's complete uncooperativeness, nausea and vomiting appear to be due mainly to symptoms of agitation that forced the denti to interrupt treatment rather than to a side effect of nitrous oxide. Although the standard procedure of inhalation of 100% O2 at the end of treatment was used in all children, nausea and vomiting would have occurred in children who required interruption for lack of adequate O2 inhalation. Headache and hyperexcitability occurred within the first 12 h of treatment, and hyperexcitability was more symptomatic because the adverse effect coincided with sleep time. Overall, the low side effect rate confirms the beneficial effect of N2O/O2 on children's relaxation during the dental procedure and the safe profile of this approach when the concentration does not exceed the recommended dose, which was also reduced to no more than 35% in our study. [PERSON] et al.