A comparison of photographic, replication and direct clinical examination methods for detecting developmental defects of enamel

BACKGROUND Different methods have been used for detecting developmental defects of enamel (DDE). This study aimed to compare photographic and replication methods with the direct clinical examination method for detecting DDE in children's permanent incisors. METHODS 110 8-10-year-old schoolchildren were randomly selected from an examined sample of 335 primary Shiraz school children. Modified DDE index was used in all three methods. Direct examinations were conducted by two calibrated examiners using flat oral mirrors and tongue blades. Photographs were taken using a digital SLR camera (Nikon D-80), macro lens, macro flashes, and matt flash filters. Impressions were taken using additional-curing silicon material and casts made in orthodontic stone. Impressions and models were both assessed using dental loupes (magnification=x3.5). Each photograph/impression/cast was assessed by two calibrated examiners. Reliability of methods was assessed using kappa agreement tests. Kappa agreement, McNemar's and two-sample proportion tests were used to compare results obtained by the photographic and replication methods with those obtained by the direct examination method. RESULTS Of the 110 invited children, 90 were photographed and 73 had impressions taken. The photographic method had higher reliability levels than the other two methods, and compared to the direct clinical examination detected significantly more subjects with DDE (P = 0.002), 3.1 times more DDE (P < 0.001) and 6.6 times more hypoplastic DDE (P < 0.001). The number of subjects with hypoplastic DDE detected by the replication method was not significantly higher than that detected by direct clinical examination (P = 0.166), but the replication detected 2.3 times more hypoplastic DDE lesions than the direct examination (P < 0.001). CONCLUSION The photographic method was much more sensitive than direct clinical examination in detecting DDE and was the best of the three methods for epidemiological studies. The replication method provided less information about DDE compared to photography. Results of this study have implications for both epidemiological and detailed clinical studies on DDE.