The intricate biomechanical relationship between the craniomandibular complex and the axial skeleton constitutes a critical, yet clinically underappreciated, functional axis. This review synthesizes evidence defining this interdependence, demonstrating a bidirectional model of influence with significant diagnostic and therapeutic implications. Acute occlusal manipulations are shown to provoke immediate and predictable postural reorganization throughout the cervical, thoracic, and lumbar spine, confirming a direct descending neuromuscular pathway. Furthermore, chronic stomatognathic states—including malocclusion, mandibular midline deviation, and posterior edentulism—are significantly correlated with established global asymmetries, such as forward head posture and lateral trunk tilt. The craniocervical junction (occiput-C1-C2) is identified as the focal point of this nexus, where temporomandibular disorders (TMD) are strongly associated with rotational misalignments that can precipitate cervicogenic pain and vertigo. Conversely, ascending influences are demonstrated by the correlation between constitutional factors, like body mass index, and spinal curvatures. The consolidated evidence challenges compartmentalized clinical approaches, mandating the integration of postural assessment into dental and surgical planning. An interdisciplinary paradigm is essential for optimizing patient outcomes and developing novel therapeutic strategies for complex, comorbid dysfunctions of the jaw and spine.