Relationship between disease characteristics and orofacial manifestations in systemic sclerosis: Canadian Systemic Sclerosis Oral Health Study III.

Objective: Systemic sclerosis (SSc; scleroderma) is associated with decreased saliva production and interincisal distance, more missing teeth, and periodontal disease. We undertook this study to determine the clinical correlates of SSc with these oral abnormalities.

Methods: Subjects were recruited from the Canadian Scleroderma Research Group cohort. Detailed dental and clinical examinations were performed according to standardized protocols. Associations between dental abnormalities and selected clinical and serologic manifestations of SSc were examined.

Results: One hundred sixty-three SSc subjects were included: 90% women, mean ± SD age 56 ± 11 years, mean ± SD disease duration 14 ± 8 years, 72% with limited cutaneous disease, and 28% with diffuse cutaneous disease. Decreased saliva production was associated with Sjögren's syndrome-related autoantibodies (β = -43.32; 95% confidence interval [95% CI] -80.89, -5.75), but not with disease severity (β = -2.51; 95% CI -8.75, 3.73). Decreased interincisal distance was related to disease severity (β = -1.02; 95% CI -1.63, -0.42) and the modified Rodnan skin thickness score (β = -0.38; 95% CI -0.53, -0.23). The number of missing teeth was associated with decreased saliva production (relative risk [RR] 0.97; 95% CI 0.94, 0.99), worse hand function (RR 1.52; 95% CI 1.13, 2.02), and the presence of gastroesophageal reflux disease (GERD; RR 1.68 [95% CI 1.14, 2.46]). No clinical or serologic variables were correlated with periodontal disease.

Conclusion: In SSc, diminished interincisal distance is related to overall disease severity. Decreased saliva production is related to concomitant Sjögren's syndrome antibodies. Tooth loss is associated with poor upper extremity function, GERD, and decreased saliva. The etiology of excess periodontal disease is likely multifactorial and remains unclear.