Dento-osseous changes as diagnostic markers in familial adenomatous polyposis families

BACKGROUND: We have previously described a weighted index for determining the diagnostic significance of dento-osseous changes observed on dental panoramic radiographs (DPRs) in individuals at 50% risk of inheriting Familial Adenomatous Polyposis (FAP). A diagnostic test based on this index (Dental Panoramic Radiograph Score, DPRS) was shown to have a sensitivity of 69% and specificity of 100%. OBJECTIVES: To evaluate the validity of the diagnostic test in an independent sample of individuals at 50% risk of inheriting FAP. DESIGN: A retrospective assessment of DPRs in individuals at 50% risk of inheriting FAP. SUBJECTS AND METHODS: A final year dental student assessed blindly and independently, DPRs from an independent sample (n = 119) of affected ( n = 26), unaffected ( n = 78) and clinically low risk individuals ( n = 15). This revealed a sensitivity and specificity of 62 and 97% respectively which is in close agreement with results of the previous study. The dental student's training in assessing DPRs was previously tested using radiographs from 81 individuals from our original study. Weighted Kappa statistics were used to test for agreement. A kappa score of 0.82 (95% confidence interval 0.70-0.93) indicated almost perfect agreement. MAIN OUTCOME: The DPRS is a reproducible and valid index for assessing the diagnostic significance of dentoosseous changes, in individuals at 50% risk of FAP, even in relatively inexperienced hands.