The Effect of Maxillary Features and Occlusal Parameters on "sh" Production in Control and Glossectomy Subjects

Abstract

This study examines the process by which the tongue articulates speech in glossectomy and control subjects using high resolution structural, and cine-MRI. Maxillary features and occlusal parameters are assessed in both groups to see if any effect on the amount of tongue volume displaced when contacting the anterior palate is noted. This volume amount is termed anteriority and measured against multiple variables. The independent variables include palate height, intercanine width, arch perimeter, orthodontic bicuspid extraction, overbite and overjet. The speech task of each subject is the sound "sh" extracted from a repeated word task. Results of the study showed statistically significant (p ≤ 0.05) differences in anteriority between glossectomy patients and controls, large versus small overbite, and an interaction between subject type and overbite. Data suggests having a larger overbite decreases the oral cavity size during "sh" sound and therefore increases tongue anteriority, especially in glossectomy subjects.