This study examines the behavior of glossectomy (N = 15) and normal tongue (N =20) movement using combination of high-resolution and cine- MRI. The speech task "a souk" was used to measure anterior tongue displacement, termed "anteriority", from /uh/ to /s/. Effects on anteriority due to palate height, /s/ type, arch perimeter, canine width, and orthodontic extraction of teeth were measured on controls and patients. Results showed that all factors except canine width had no significant difference in anteriority of tongue. Canine width was significantly related to anteriority in an inverse relationship. The fact that arch perimeter is less important than canine width on anteriority is consistent with our understanding of the criticality of the location of the tongue tip, rather than the tongue body, in producing /s/. Data also suggests that less than average arch perimeter improves speech intelligibility in patients with T2 tumor of the tongue.