The temporomandibular ligament as a tethered radius guiding articular eminence development during craniofacial growth

The articular eminence is shallow at birth and acquires its adult height and inclination during craniofacial growth. Eminence morphology correlates strongly with facial divergence, condylar position, and temporomandibular joint pathology, yet no accepted mechanism explains how these relationships arise. We propose that the temporomandibular ligament (TML) acts as a geometric and mechanical mediator between mandibular growth rotation and articular eminence morphogenesis through a tethered radius mechanism. As mandibular growth alters condylar position within a suspended system, the ligament develops sustained tension that is transmitted through a distributed enthesis along the posterior eminence slope, providing directionally biased cues for bone modeling via established mechanotransduction pathways and vascular regulation. Mandibular growth rotation modulates this system in three dimensions: forward rotation maintains oblique tensile engagement that favors steep eminence development, whereas backward rotation reduces directional tension and shifts the mechanical environment toward relatively greater compressive joint loading, producing flatter morphology. Ligament tension provides directional guidance, while condylar compression supplies stimulus magnitude, and both contribute to normal development. The model predicts correlations between ligament geometry and eminence inclination in sagittal and coronal planes and reframes associations between occlusal morphology and eminence form as coordinated outputs of a shared mechanical system rather than direct dental causation. This mechanistic framework is anatomically grounded and experimentally falsifiable, providing a unified framework for understanding articular eminence development.