Alison Sigal
This study examines the in vivo tongue resting configuration in relation to lingual mobility. While biomechanical models suggest the tongue may exhibit properties consistent with a muscular hydrostat, direct large-scale clinical observation of resting posture remains limited. The objective was to characterize tongue resting configuration before and after removal of lingual mechanical restriction (ankyloglossia), and to evaluate whether observed behavior aligns with hydrostatic principles. A retrospective cohort study was conducted at a single center pediatric specialty practice from September 2017 to November 2025. Patients were categorized by procedural setting, including an awake infant cohort (n = 3182) and a general anesthesia cohort (n = 355). Resting tongue position was assessed before and after the intervention using standardized observational techniques, with paired analyses performed. Full-length palatal contact increased from 0.0% pre-procedure to 99.5% postoperatively in the awake cohort (p < 0.001). In the general anesthesia cohort, 100% of patients demonstrated full-length palatal contact intraoperatively following restoration of unrestricted mobility (p < 0.001), regardless of age or palatal morphology. These findings demonstrate that, when unrestricted, the tongue consistently assumes a palatal resting configuration in vivo. This behavior is consistent with muscular hydrostat principles and supports consideration of the living tongue as a muscular hydrostat from a functional perspective.