Objectives <p>This single-arm clinical trial investigated changes in condylar displacement, total of force (TOF), and force distribution during the initial phase of passive clear-aligner wear.</p> Materials and methods <p> The mandibular condylar displacement (MCD) instrument was employed to measure sagittal, vertical, and horizontal condylar displacement. Simultaneously, the T-Scan system was used to analyze the total of force (TOF), force distribution and occlusal balance. The study comprised twelve healthy adult participants (nine females and three males; mean age: 25.6 years). These individuals consecutively wore two pairs of passive clear aligners for a duration of ten days each. Assessments were conducted on baseline (Day 0), Day 10, and Day 20.</p> Results <p> TOF significantly decreased over time (P &lt; 0.05), whereas no notable alterations were observed in other evaluated parameters. In Group CHANGED, TOF markedly decreased on Day 10 and showed partial recovery on Day 20. Statistically significant differences in the anterior/posterior (A/P) bite force ratio between the groups were identified on day 10 and day 20 (P &lt; 0.05). Condylar displacement demonstrated significant increases in both vertical and sagittal dimensions (P &lt; 0.05), predominantly in the distal and downward directions.</p> Conclusions <p> Passive clear‑aligner wear transiently decreases TOF and occlusal balance during the initial 20 days. The anterior–posterior force ratio may act as a clinical marker for upcoming shifts in mandibular position. Although the average MCD remained stable, some participants exhibited distal‑downward condylar drift.</p> Clinical relevance <p> Clear aligners have the potential to alter mandibular position downward and distally while somewhat reducing bite forces.</p>