Three-dimensional analysis of vocal fold nodules in operatic soprano singers undergoing microlaryngeal surgery: Differences according to voice type subcategories (Lyric vs. Dramatic)

OBJECTIVES: Vocal demands in opera singers vary not only by vocal range but also by voice type subcategories (e.g., lyric vs. dramatic), which shapes technique and repertoire. Despite this, little is known about how these voice subcategories influence vocal fold pathology. To address this gap, we investigate the three-dimensional characteristics of vocal fold nodules in professional soprano opera singers and to clarify morphological differences based on voice type subcategories (lyric vs. dramatic). METHODS: This retrospective study included 19 professional soprano singers who underwent microlaryngeal surgery for bilateral vocal fold nodules between January 2018 and May 2023. Voice type subcategories, based on self-reported repertoire, was categorized as either lyric or dramatic. Nodules were classified as edematous or fibrous. Vertical location, estimated area, estimated contact area, and estimated volume of the nodules were calculated using intraoperative measurements and surgical video review. Statistical comparisons were performed between the lyric and dramatic groups. RESULTS: A total of 38 nodules were analyzed: 26 from lyric sopranos and 12 from dramatic sopranos. Lyric sopranos predominantly exhibited edematous nodules (24/26), while dramatic sopranos had a higher proportion of fibrous nodules (6/12). In both groups, nodules were more frequently located in the upper part of the vocal folds. Lyric sopranos showed significantly greater width, estimated area, estimated contact area, and estimated volume of vocal fold nodules compared to dramatic sopranos. CONCLUSION: Voice-type subcategories may influence the morphological characteristics of vocal fold nodules in professional soprano singers. Lyric sopranos tend to develop larger, edematous nodules, likely due to repetitive high-frequency phonation, while dramatic sopranos are more prone to smaller, fibrotic nodules, potentially resulting from greater horizontal mechanical stress.