Sublingual Abnormalities in Systemic Sclerosis

Sublingual frenulum abnormalities have been observed in systemic sclerosis (SSc), but the clinical significance of such features is not known. The goal of this project was to devise a reliable bedside tool to confirm the presence of sublingual frenulum abnormalities in SSc and explore potential associations with patient demographics and gastrointestinal clinical phenotype.

A working group was created to develop a semiquantitative assessment tool for assessing sublingual abnormalities, the Sublingual Abnormalities Index (SAI). Sublingual frenulum thickness, frenulum length, sublingual buccal mucosa pallor, and the presence of oral telangiectasia were each individually scored using 0- to 2-point Likert scales and a composite score of the 4 domains created by summation of the individual scores. Assessment of the sublingual region of 21 patients with SSc and 8 control subjects was undertaken. An image of the sublingual frenulum was obtained using prespecified camera settings to allow assessment of interrater reliability with 2 independent blinded assessors.

Scores for each of the SAI domains differed between control subject and SSc population (P = 0.0003). Patients with SSc had a composite SAI score of 4.3 (SD, 0.37). None of the control subjects had a composite SAI score of more than 2. There was excellent interrater reliability between clinician assessment and each blinded assessor (Cohen κ's of 0.72 and 0.82, respectively).

This feasibility study confirms the presence of clinical sublingual abnormalities in SSc, which can be categorized using a simple scoring chart with moderate to near-perfect interrater agreement. The functional significance and pathogenesis of this abnormality warrant further study.