Does Race Influence Velopharyngeal Structure Size and Velar Stretch During Sustained Phoneme Production in Children?

Differences in the size of velopharyngeal structures across racial groups at rest have been described in the literature, with race influencing adenoid thickness, pharyngeal depth, effective velar length, and velar length. The purpose of this study was to examine differences in velopharyngeal anatomy and velar stretch during sustained phoneme production in two racial groups.

A cross-sectional design was utilized for the study. Five- and 6-year-old children who were either Black or White completed structural magnetic resonance imaging scans in the midsagittal plane at rest, during /i/, and during /s/. Outcome measures were velar length at rest, during /i/, and during /s/; effective velar length at rest, during /i/, and during /s/; velar thickness at rest, during /i/, and during /s/; velar stretch during /i/ and /s/; pharyngeal depth; adenoid depth; functional adenoid thickness; velopharyngeal ratio; and effective velopharyngeal ratio.

Twenty-five participants were included in the study: 11 Black participants and 14 White participants. Six variables were significantly associated with race: effective velar length at rest (p < .001, Black [B] > White [W]), effective velar length during /s/ (p = .011, B > W), velar thickness during /i/ (p = .036, B > W), velar thickness during /s/ (p = .037, B > W), velar stretch during /i/ (p = .011. W > B), and velar stretch during /s/ (p = .040, W > B). Three additional variables had medium effect sizes: velar length during /i/ and /s/ (B > W) and effective velar length during /s/ (B > W).

Black children in the study presented with significantly longer effective velums and significantly thicker velums during sustained phoneme production, resulting in Black children needing significantly less velar stretch than White children. Based on this, race-specific preliminary reference data for velopharyngeal anatomy during sustained phoneme production are needed to allow clinicians to interpret individual patient imaging within the appropriate demographic context. Without race-specific reference data, a Black child with velopharyngeal insufficiency whose velar measurements fall within the typical range for White children may go unrecognized, as what appears to be "normal" for a White child may not be normal for a Black child.