Tongue pressure production and orofacial muscle activities during swallowing are related to palatal morphology in individuals with normal occlusion

Abstract

ABSTRACT Purpose The relationships between motor function, including the orofacial muscles coordinated with the tongue during swallowing, and palatal morphology are still unclear. This study aimed to identify the relationships between tongue pressure production and orofacial muscle activities during swallowing and palatal morphology. Materials and methods The participants were 20 healthy volunteers with individual normal occlusion (8 men, 12 women; mean age: 25.0 ± 2.9 years). Tongue pressure and masseter, orbicularis oris, mentalis and supra-infrahyoid muscle activities during 4 ml gel swallowing were recorded simultaneously by a sensor sheet system, with five measuring points and surface electromyography, respectively. Onset, offset and duration of each parameter and the maximum magnitude of tongue pressure were analysed. Palatal width and depth were measured using three-dimensional digital images of maxillary dental models and examined for correlations with tongue pressure and orofacial muscle activities. Results The temporal coordination between tongue pressure production and orofacial muscle activities during swallowing was observed. The maximum magnitude of tongue pressure was significantly positively correlated with the palatal width. Palatal depth showed significant correlations with the time sequences of tongue pressure and orbicularis oris and mentalis muscle activities. Conclusion These results suggest that tongue pressure production and orofacial muscle activities during swallowing are related to palatal width and depth.