The Levator Veli Palatini: Are all Segments Created Equal?

INTRODUCTION: The levator veli palatini (LVP) muscle has two segments with distinct roles in velopharyngeal function. Previous research suggests longer extravelar segments with shorter intravelar segments may lead to a more advantageous mechanism for velopharyngeal closure. The purpose of this study was to examine whether the distribution of the LVP intravelar and extravelar segments differs between children with cleft palate with and without VPI and controls. METHODS: The study included 97 children: 37 with cleft palate +/- lip with VPI, 37 controls, and 19 with cleft palate with normal resonance. Measures included mean LVP length, mean extravelar LVP length, and intravelar LVP length. RESULTS: Overall mean LVP length was similar (P = .267) between controls and children with cleft palate (with and without VPI). However, there was a significant difference (P < .001) between group for both intravelar and extravelar LVP lengths: the intravelar segment was significantly longer in those with VPI compared to controls and children with cleft palate and normal resonance; and the extravelar segment was significantly shorter in those with VPI compared to controls and children with cleft palate and normal resonance. CONCLUSIONS: Results from this study demonstrate a significant difference between the distribution of the functional segments of the LVP among children with VPI, with a more disadvantageous distribution of the muscle segments among those with VPI.