Contracted Extravelar Segments of the Levator Veli Palatini Muscle: A Magnetic Resonance Imaging Morphometric Study

Abstract

Objectives: To provide detailed descriptions of contraction-induced morphometric changes in the extravelar segments of the levator veli palatini (LVP) muscle using 3-dimensional (3-D) magnetic resonance imaging (MRI). Design: Three-dimensional MRI data were acquired at rest and during “silent /i/” from 4 singers. During silent /i/, participants voluntarily sustained velar elevation while breathing orally for the entire scan time. Focusing on the extravelar segments, LVP length, angle of the muscle origin, and cross-sectional area (CSA), measurements were obtained and compared between tasks. Results: Three of the 4 participants exhibited the expected patterns of change following concentric contraction of the LVP muscle. Consistent changes from the resting to the contracted state included reductions in LVP length by 13.5% and angle of the muscle origin by 9.8%, as well as increases in CSAs by 22.1%, on average. Conclusions: This study presented high-resolution data of the LVP muscle behavior with the first in vivo 3-D measurements of the contracted LVP muscle, which can be useful for the validation of computational models that aim at describing biomechanical properties of the LVP muscle in future research. The active behavior of the extravelar LVP muscle also provides some insight on optimal LVP muscle geometry to consider during cleft palate repair.

Simulation of Velopharyngeal Biomechanics Identifies Differences in Sphincter Pharyngoplasty Outcomes: A Matched Case–Control Study

“…LVP muscle morphology has been reported in the literature. 29,57,60 Kotlarek et al 57 reported significant differences in the LVP morphology and symmetry at the velum insertion points among children with repaired cleft palate and a greater degree of asymmetry was found in children with cleft-related velopharyngeal insufficiency. In contrast, Tahmasebifard et al 61 found no significant difference between right and left LVP muscle symmetry among participants without cleft palate.…”