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Objectives. The diagnostic accuracy of direct digital radiography for the detection of small experimentally made periapical lesions was evaluated. A comparison was made between original digital images and images processed with different enhancement facilities of the digital system. Study design. Seven observers assessed the digital images in original mode and after individual image treatment. The diagnostic accuracy was calculated. The processing functions used by the observers were recorded, and the effect of processing was evaluated. Results. The overall diagnostic accuracy was not different for the two image modes. Neither were the individual results of the observers different. The image processing was most effective when alterings of contrast and brightness were used. More complicated processing procedures had less effect on the diagnostic accuracy. Conclusions. Image processing of direct digital images of high quality has a limited effect on the diagnostic accuracy. Basic processing functions, that is, alterings of contrast and brightness, were preferred for the detection of periapical lesions.

Objective To study the diagnostic outcome of periapical radiography in the assessment of the bone trabecular pattern of the mandible. Study Design Mandibular autopsy specimens were radiographed. Seven observers assessed the radiographs with the aid of a proposed classification with and without reference images and the classification presented by Lekholm and Zarb. Accuracy was estimated on the basis of morphometric measurements of trabecular bone volume. Observer agreement was calculated as the estimated probability of agreement between and within observers and as Kappa index. Results With the classification proposed by us, the overall accuracy was 58% with and 50% without reference images. The accuracy for assessing dense trabeculation was higher (78%) than that for sparse trabeculation (28%). The accuracy of the proposed classification by Lekholm and Zarb was not possible to evaluate. The interobserver agreement varied between 49% and 64% and the intraobserver agreement between 75% and 86%. Conclusions A new classification with reference images is recommended to assess the trabecular pattern in periapical radiographs before implant treatment.

Objective To measure the prevalence of disease of mandibular third molars referred for removal and to estimate the risk for development of pathoses for two cues. Study design A prospective cohort study on molars subjected to removal was performed. The prevalence of different diseases and the patient's age, angular position, and degree of impaction of the molars were registered. Odds ratio for molars with different positions and impaction states were estimated. Results Pericoronitis was found in 64% of cases, caries in the third molar in 31%, periodontitis in association with 8%, caries in the second molar in 5%, and root resorption of the second molar with 1% of the molars with pathoses. Odds ratio was highest for distoangular molars (5.8) and for molars partially covered by soft tissue (6.7). Conclusions The odds ratio is about 22 and 34 times higher for molars partially covered by soft tissue than for molars completely covered by soft or bone tissue. For distoangular molars the odds ratio is 5 to 12 times higher than for molars in other positions.