Performance of self-reported measures for periodontitis in rheumatoid arthritis and osteoarthritis.

BACKGROUND: This study evaluates the performance of self-report against the reference standard of clinically defined periodontitis in patients with rheumatoid arthritis (RA) and osteoarthritis (OA) after accounting for factors associated with periodontitis. METHODS: Six self-report periodontitis questions were evaluated in patients with RA and OA. Questions were validated against a reference standard of severe and moderate-to-severe periodontitis based on full-mouth examination. Multivariable logistic regression was used to evaluate the performance of: 1) self-report alone; 2) age, sex, education, and smoking status; and 3) a combination of the above. Model performance was assessed using the c-statistic. Convergent validity of self-reported "bone loss/deep pockets" and "loose teeth" was assessed; associations of self-report with RA disease characteristics were explored. RESULTS: Self-report performed similarly in RA and OA, with individual question specificity for periodontitis ≥ 68% and sensitivity from 9.8% to 45%. Question-only models yielded c-statistics of 0.66 to 0.72, whereas risk factor-only models yielded c-statistics of 0.74 to 0.79. The highest-performing models incorporated both self-report questions and periodontitis risk factors, with c-statistics ≥ 0.79. Greater radiographic alveolar bone loss was observed among participants reporting "bone loss/deep pockets" (P < 0.001) and "loose teeth" (P < 0.001). Among patients with RA, "loose teeth," but not other self-report items, was associated with rheumatoid factor positivity (P = 0.047) and higher disease activity (P < 0.001). CONCLUSIONS: Patient self-report, when combined with other risk factors, performs well in identifying periodontitis among patients with RA and OA. Self-report questions related to alveolar bone loss exhibit excellent convergent validity in these patient subsets.

Clinical ligation forces and intraoral friction during sliding on a stainless steel archwire.

The efficiency of tooth movement associated with some orthodontic mechanics can be compromised by friction between archwire and bracket. This study examined the effects of bracket ligation forces (F(N Ligation)) and mastication on friction when sliding a bracket along an archwire. Preliminary data from 5 orthodontists and 5 orthodontic residents characterized average tight and loose stainless steel F(N Ligation). These values were reproduced by a calibrated operator in a custom device used to estimate changes in the measurement of ex vivo and intraoral frictional forces, represented by mu(a), the apparent coefficient of static friction. Ten subjects chewed gum with the device in place to determine whether vibration eliminated friction when compared to ex vivo measurements. Nested analysis of variance and Tukey HSD tests determined the effects of ligation type and environmental variables. No significant differences (P >.01) were found between ex vivo and intraoral mu(a) values for tight and loose stainless steel ligation. Intraoral mu(a) values for elastic ligation were significantly greater than ex vivo mu(a) values (P