Objective: To determine 1) the role, function of structures, and patterns of Velpharyngeal [VP] gap formation among people with Cleft lip and palate [CLP], and 2) the inter-reliability between 2 investigators on the objective assessment of VP gap and its respective patterns.
Materials and Methods: This was a descriptive and retrospective study data collection among. Patients with velopharyngeal insufficiency [VPI]’s medical records were retrieved. Outcomes of perceptual assessment and objective evaluation of velopharyngeal movement (using Motic plus 2.0 software) were analyzed. Descriptive analyses, intra-class correlations, and Kappa coefficient were used to characterize the data.
Results: Twenty-three participants between 8 and 47 years of age were enrolled. Oronasal fistula was found 23.81% Coronal
patterns of the VP gap and tongue compensation movement were common in patients with VPI. The respective correlation
coefficient between the perceptual resonance rating scale and nasalance scores for Thai standard passages My house, Winter, and Laying Hen was 0.37 (95% CI = -0.06, 0.68), 0.26 (95% CI = -0.19, 0.62), and 0.30 (95% CI = -0.14, 0.64). The respective correlation coefficient between the nasalance scores for the Thai standard passages and articulation types was -0.29 (95% CI = -0.63, 0.16), -0.41 (95% CI = -0.71, 0.03), and -0.19 (95% CI = -0.57, 0.25). The correlation coefficient for articulation types and the perceptual resonance rating scale was 0.08 (95% CI = -0.22, 0.58). The intra-class correlation coefficient between the two investigators for VP gap for each sound was 0.78 to 0.82, while the range of kappa coefficient between the two investigators for the VP pattern gap for each sound was 0.16 to 0.30.
Conclusion: Velum had the primary role vis-a-vis VP function while the posterior pharyngeal wall had minimal function in VP gap formation. Coronal patterns of VP gap and tongue compensation movement were common in patients with VPI.

Keywords: VPI, Cleft lip and palate, Objective measurement, Oronasal fistula