Objectives: Our aim was to study whether the Modified Dental Anxiety Scale (MDAS) is reliable and valid for use in children aged 9 to 12 years. 

Methods: The study population was a convenient sample of Finnish comprehensive school pupils in the third and sixth grades (N = 57 and N = 69, respectively). Dental fear and anxiety (DFA) were measured with the Finnish validated adult version of MDAS, the modified Child Fear Survey Schedule-Dental Subscale (CFSS-DS-M), and a single question. Reliability was evaluated using Cronbach's alpha. The criterion validity of MDAS was assessed using Spearman rank correlation coefficients against CFSS-DS-M and the single question. Construct validity was assessed by examining the ability of MDAS to find differences according to gender and treatment procedures using the chi-square test for categorized and the Mann-Whitney and Jonckheere-Terpstra tests for continuous variables. 

Results: The Cronbach alphas were 0.841, 0.708, and 0.778 for MDAS total, anticipatory, and treatment-related DFA, respectively. Correlations between MDAS and CFSS-DS-M total and subscale scores were moderate to strong (ρ = 0.559-0.794), supporting criterion validity. Girls in third grade had lower mean MDAS anticipatory DFA (3.4, SD = 1.44) than boys (4.5, SD = 2.21, p = 0.051). In sixth graders, girls had higher mean MDAS treatment-related DFA (8.4, SD = 3.17) than boys (6.9, SD = 2.61, p = 0.067). Children reporting orthodontic treatment had lower anticipatory DFA (mean = 3.4, SD = 2.13) than children not reporting (mean = 4.0, SD = 1.83; p = 0.009), supporting construct validity. 

Conclusions: The Finnish version of the MDAS showed good reliability, good criterion validity, and acceptable construct validity, supporting its use in children aged 9-12 years.