Assessment of posterior tongue mobility using lingual‐palatal suction: Progress towards a functional definition of ankyloglossia

BACKGROUND: A functional definition of ankyloglossia has been based on assessment of tongue mobility using the tongue range of motion ratio (TRMR) with the tongue tip extended towards the incisive papilla (TIP). Whereas this measurement has been helpful in assessing for variations in the mobility of the anterior one‐third of the tongue (tongue tip and apex), it may be insufficient to adequately assess the mobility of the posterior two‐thirds body of the tongue. A commonly used modification is to assess TRMR while the tongue is held in suction against the roof of the mouth in lingual‐palatal suction (LPS). OBJECTIVE: This study aims to explore the utility and normative values of TRMR‐LPS as an adjunct to functional assessment of tongue mobility using TRMR‐TIP. STUDY DESIGN: Cross‐sectional cohort study of 611 subjects (ages: 3‐83 years) from the general population. METHODS: Measurements of tongue mobility using TRMR were performed with TIP and LPS functional movements. Objective TRMR measurements were compared with subjective self‐assessment of resting tongue position, ease or difficulty elevating the tongue tip to the palate, and ease or difficulty elevating the tongue body to the palate. RESULTS: There was a statistically significant association between the objective measures of TRMR‐TIP and TRMR‐LPS and subjective reports of tongue mobility. LPS measurements were much more highly correlated with differences in elevating the posterior body of the tongue as compared to TIP measurements (R(2) 0.31 vs 0.05, P < .0001). CONCLUSIONS: This study validates the TRMR‐LPS as a useful functional metric for assessment of posterior tongue mobility.