Agreement after joint evaluation was obtained for all the cases selected for discussion. Twenty-five diagnoses were established and seven cases were rejected owing to substandard radiographs. The rejected cases had all formerly been suggested for rejection, but one case rejected by two observers was given a diagnosis when discussed jointly. Cases from six patients, representing different teeth/roots illustrating rather typical problems discussed during joint evaluation are shown in Figs 1-6.
A tooth that caused frequent problems was the maxillary lateral incisor. The varying morphology of its apical area and varying density of the surrounding bone presented a number of challenges. Figure 1 shows a case with somewhat atypical apical morphology. One observer recorded this initially as a widened periodontal space, emphasizing the impression from using less intense viewing light, simulated in the left illustration. The final consensus diagnosis was, however, normal condition, mostly resulting from viewing conditions simulated in the illustration on the right.
Figure 2 shows a case where the initial suggestions were normal and apical periodontitis. The final diagnosis became apical periodontitis, and the bony destruction was assumed to be located buccal or palatal in relation to the radiographic apex. Comparison with the contralateral tooth gave little support for any of the alternatives.
Figure 3 shows a situation in the mandibular anterior region. From the trabecular pattern in the region, the radiolucency seen in the apical area of the right lateral incisor might represent normal morphology. Two images made with different projections failed, however, to show any movement of the radiolucency relative to the landmarks of the root. The observers here agreed with some uncertainty upon the diagnosis of apical periodontitis.
The initial evaluations of the apical area of the first maxillary premolar shown in Fig. 4 were normal condition and apical periodontitis. The joint discussion settle dupon normal condition, interpreting the radiolucency as a bone marrow space. The absence of a clearly depicted lamina dura in the apical area was considered as being caused by the same anatomical and technical factors as those causing its absence on the distal root surface.
A similar problem is illustrated in Fig. 5. One observer recorded a mesial apical periodontitis, interpreting the radiolucency imaged around the surplus root-filling material as representing a true pathosis. The conclusion of the joint discussion was normal condition, based on the similarity to the rather typical marrow space seen immediately inferior to the distal root and also because portions of the lamina dura were discernible.
The second maxillary molar illustrated in Fig. 6 exhibits a well-delineated radiolucency depicted over the mesial root and the furcation area. Also in this case, the options were either definitely normal or definitely pathological. The final decision was normal condition, based on arguments of similar bony configurations in the edentulous area posterior to this tooth. The differential diagnoses were furcation involvement and osteitis in juxtaposition. These alternatives were discarded especially because of the sharp, cortical borderlines of the radiolucent structure.
Figure 1. Lateral incisor with a typical apical morphology. Final decision: normal condition. See text for supplementary information on this and other illustrated cases.
Figure 2. Lateral incisor (left) interpreted as apical periodontitis, opposite side (right) presented for comparison.
Figure 3. Lateral incisor interpreted as apical periodontitis.
Figure 4. First premolar interpreted as normal condition, i.e. bone marrow space.
Figure 5. First molar with surplus root-filling material at the mesial root interpreted as normal condition.
Figure 6. Second molar with normal periapical condition. The radiolucency depicted over the furcation area was interpreted as normal morphological variant.