Quantitative Analysis of Velopharyngeal Movement by Applying Principal Component Analysis to Range Images Produced by a Three-Dimensional Endoscope.

Asuka Nakano,Hirotsugu Umeda,Hiroyuki Nakano,Yoshiya Ueyama,Katsuaki Mishima,Mami Shiraishi

doi:10.3390/dj5020014

Abstract

Objectives: The purpose of this study was to develop a new technique for analyzing velopharyngeal movement and to investigate its utility. Materials and Methods: Velopharyngeal motion of 20 normal individuals was analyzed. A three-dimensional (3D) endoscope was inserted into the oral cavity, and the movement of the soft palate was measured using an exclusive fixation device. Range images of the soft palate were produced during phonation of the Japanese vowel /a/, and virtual grids were then overlaid on these images. Principal component analyses were applied to the 3D coordinates of the intersections of the virtual grids. The centers of gravity of the virtual grids were calculated, and the magnitude of the shift of the grid intersections during phonation was calculated. Results: The first and the second principal component scores were responsible for the upper posterior direction and the upper direction, respectively. The average magnitude of the shift of the center of gravity was 4.75 mm in males and 4.33 mm in females. Conclusions: Quantitative analysis of velopharyngeal movement was achieved by a method of applying principal component analysis (PCA) to the range images obtained from a 3D endoscope. There was no sex difference in velopharyngeal movement.

Highlights

For individuals with a cleft palate, it is important to acquire velopharyngeal function by surgical reconstruction and postoperative speech therapy in order to develop normal speech [1,2,3]
The first principal component scores (PCSs) showed a wider distribution in females than in males (Figure 6)
Discriminant analysis was able to correctly discriminate the velopharyngeal movement for males and females in 54.6% of the cases

Summary

Introduction

For individuals with a cleft palate, it is important to acquire velopharyngeal function by surgical reconstruction and postoperative speech therapy in order to develop normal speech [1,2,3]. The precise evaluation of velopharyngeal movement is necessary in speech therapy. Nasopharyngoscopy has been widely used to diagnose velopharyngeal closure, it can only provide a qualitative assessment [4,5]. To be able to evaluate velopharyngeal function in detail, it is necessary to measure velopharyngeal movement quantitatively. This means that, to measure velopharyngeal movement quantitatively and precisely, it is necessary for us to be able to use four-dimensional information in detail, adding the temporal axis element to the three-dimensional spatial information

Objectives

Methods

Results

Conclusion