Various methods have been employed to determine skeletal maturity, based on height, weight, frontal sinus development, dental calcification sexual maturation and biomarkers. This study aimed to evaluate the validity and reliability of the Quantitative Cervical Vertebral Maturation Index (QCVMI) in assessing skeletal maturity and compare it with established radiographic maturity indicators, including Fishman's Skeletal Maturity Index, Hassal and Farman's CVMI, Modified MP3 Method, Baccetti's CVMI and correlation between QCVMI and mandibular growth increments.

A cross-sectional study was conducted on 120 patients. Lateral cephalograms and hand-wrist radiographs were analysed using Digimizer software. Agreement analysis was performed using Bland-Altman plots, while inter- and intra-rater reliability was assessed using Intraclass Correlation Coefficients (ICC). Lin's Concordance Correlation Coefficient (CCC) and the Bradley-Blackwood test were used for comparative assessment. ROC curve analysis determined diagnostic accuracy, and Pearson correlation coefficients and regression analysis assessed the relationship between QCVMI and mandibular growth increments.

QCVMI demonstrated excellent agreement with Fishman's SMI, very good agreement with the Modified MP3, and good agreement with Hassal and Farman's CVMI and Baccetti's CVMI. High intra- and inter-rater reliability confirmed its reproducibility. ROC analysis showed QCVMI had the highest diagnostic accuracy compared to Fishman's SMI. A strong correlation was observed between QCVMI and mandibular growth increments, indicating its predictive efficacy for growth spurts.

QCVMI is a valid and reliable skeletal maturity assessment tool, demonstrating strong agreement with established indicators while enhancing objectivity and reproducibility. It effectively predicts mandibular growth spurts, making it valuable for orthodontic treatment planning.