Comparative evaluation of vertical dimension changes with clear aligners and fixed appliances: A prospective cephalometric cohort study

Background The control of vertical dimension remains a critical aspect of comprehensive orthodontic treatment. This study compared vertical dimensional changes produced by clear aligners (CAs) to those produced by fixed appliances (FAs) during comprehensive orthodontic treatment, assessing whether modern aligner therapy provides comparable vertical control with conventional mechanics. Methods A prospective cohort of 52 adults (CA group: 26 and FA group: 26) was evaluated. Baseline comparability was confirmed for age, sex, malocclusion type, and skeletal pattern. Standardized lateral cephalograms were obtained before (T 0 ) and after treatment (T 1 ). Cephalometric variables included the SN-GoGn (mandibular plane angle), FMA (Frankfort-mandibular plane angle), N–Me (total anterior facial height), S–Go (posterior facial height), and ANS–Me (lower anterior facial height). Intraobserver and interobserver reliability exceeded an intraclass correlation coefficient of 0.90. Paired and intergroup comparisons were performed (α = 0.05). Results Both groups exhibited small increases in vertical parameters within physiological limits. In the CA group, the SN-GoGn angle showed a statistically significant but clinically minor increase (