Results
lethargy, bradycardia, hypotension
ADVERSE EVENTS
In total, 107 dental patients aged 3 to 12 years were recruited from January 20, 2021 to February 20, 2021. Among them, 13 patients did not meet the inclusion criteria and were excluded, and four patients refused to participate. Accordingly, 90 patients were randomly divided into two groups. However, two participants in M group and three participants in DM group requested to withdraw during the study, and two participants in DM group were lost to follow-up. Therefore, 83 participants completed the final analyses, as illustrated in Fig. 
CONSORT 2010 Flow DiagramThe average age of the 83 participants (32 boys; 38.6%) was 6.1 years (standard deviation, 2.7 years). The characteristics of the participants in the baseline and clinical characteristics are presented in Table 
Comparison of demographic information and clinical characteristics of recruited participants for the two groupsvalues in number mean ± standard deviation (SD)The Mann–Whitney U test was used to examine potential differences between groups in the RSS, Frankl scale, and Houpt scale (Figs. 
Ramsay scores for two groups
Frankl scores for two groups
Houpt scores for two groupsAmong the 43 participants in M group, 21 (48.8%) were successfully sedated with scheduled dental treatment, but 22 (51.2%) were not. Among the 40 participants in DM group, 31 (77.5%) received successful sedation with the corresponding dental treatment, but nine (22.5%) were not successfully sedated. The odd ratio (95% CI) for successful sedation between oral midazolam plus intranasal dexmedetomidine and oral midazolam estimated to be 3.61 (1.39-9.36), During treatment, the blood oxygen saturation of the two groups fluctuated within the normal range, but no oxygen saturation decreased below 95%. In DM group, one participant had bradycardia (heart rate dropped to 60 beats per minute in the dental procedure), another participant occurred hypotension (systolic blood pressure dropped to 90 mmHg in procedure). However, no patient required the intervention of the anesthesiologist, both patients returned to normal within a minute. Five children (12.5%) in DM group, showed signs of lethargy, and none of this sign was seen in M group (
absolute and relative frequencies of adverse events related to sedative groups*Significant differences (P < 0.05)Upon questionnaires interviewed at 24 h after discharge, the parents reported that all adverse events had disappeared without any new adverse events. In M group, the parents of 23 participants (53.5%) were very satisfied with the sedation treatment, the parents of 20 participants (46.5%) were generally satisfied, and no parents were dissatisfied (Table 
Parents’ attitudes towards sedation treatment*Significant differences (P < 0.05)