Although there are many reports searching for an ideal method for imaging and measurements of swallowing, there is little information about methods applicable to children. In addition, despite the key roles played during the oral phase of swallowing, little is known about the relationship between tongue movements and the structure of the hard palate. The purpose of this study was to design a standardized method of tongue surface imaging for children by applying a helmet-type transducer holder, and to clarify the influence on the hard palate structure to tongue surface movement.
Fifteen normal children (age 3 y 8 m to 6 y 5 m) with full deciduous dentition were studied using the ultrasound of a coronal scanning view of tongue surfaces while swallowing apple juice (2 cc) and yogurt (2 g). The results were as follows:
1. The tongue grooving depth when swallowing yogurt increased significantly compared to juice.
2. The grooving duration was significantly longer than groove disappearance duration.
3. Grooving speed when swallowing yogurt was significantly faster compared to juice. Groove disappearance speed was significantly faster than grooving speed in both foods.
4. There was a significant correlation between palate depth and grooving depth while swallowing yogurt. (r=0.51)
5. There was a significant correlation between palate volume and grooving duration while swallowing juice. (r=0.54)
Our new method using the helmet-type transducer holder made it easier to measure the grooving depth, width, time and speed of the tongue at a certain scanning plane. We conclude that tongue surface movements are mutually related to palate volume and palate depth. It is essential that we examine the palate structure and take it into consideration when examining children, especially those with cerebral palsy or cleft palate who have abnormal palates affecting swallowing skills.