Assessing skeletal maturity is a critical factor in orthopedic treatment and orthognathic surgery. Quantitative methods have been suggested to decide the skeletal age. This study aims to assess the correlation between the middle phalanx of the third finger (MP3) method and cervical vertebral volume parameters (CVVP) in skeletal age determination. This cross-sectional study was conducted on 21 boys and 29 girls between the ages of 8 and 16 years, who were divided into five groups of skeletal maturation: 100 MP3 radiographs and cone beam computed tomography (CBCT) were obtained and analyzed. Middle phalanx of the third finger maturation stages were evaluated according to Perinetti method (stages F-FG-G-H-I). The CVVP was determined on CBCT using Mimics Medical software. Analysis of variance (ANOVA) and Bonferroni tests were utilized to investigate the differences in volumetric parameters between MP3 stages. Spearman correlation coefficient was employed to obtain the correlation between MP3 stages and the CVVP. The differences in CVVP concentrated between MP3-I stage and the previous stages, with the highest values those for the 4th vertebra. Spearman test revealed a significant highest correlation between MP3 stages and the CVVP in the 4th vertebra; the lowest was in the 2nd, which was higher in the girls group. Strong level of agreement between the two methods was significant in the 4th vertebra. Measurement of volumes of the 4th CVVP could be used as simple quantitative analysis in clinical practice to evaluate the maturity in orthodontic patients.