Background and objects : The radiographic criteria of bisphosphonate-related osteonecrosis of the jaws (BRONJ) have only been investigated in few studies yet. All of them comprised just limited cohorts. It is still unclear, whether the greater effort of three-dimensional imaging is justified. For that reason, we analyzed the quality and quantity of defined radiographic criteria in a larger cohort ( N = 101) ï¿1/2 in two-, as well as in three-dimensional datasets.

Methods : Inclusion criteria were patient-data with diagnosis of BRONJ (AAOMS 2007) level 1 or above. Conventional and three-dimensional imaging (CT and Cone-Beam scans) of 101 patients were evaluated by an experienced radiologist. The primary diagnostic criteria were periosteal sclerosis, osteolysis, cortico-medullar dedifferentiation, ghost-sockets, and sequestration. Emphasis was placed on the extent of the lesions to estimate the severity of necrosis.

Results : The majority of defects (>70%) were detected in both two- and three-dimensional techniques. A measurement of the size was not possible in conventional radiographs due to a lack of a fixed scale. In direct comparison of the two procedures, it could be shown, that primarily single-wall-defects, sequestrations and periosteal sclerosis were safer to identify in three-dimensional scans than in conventional images.

Clonclusions : The differences in the investigated techniques reveal the known (dis-)advantages of conventional radiography. Beneficially, detail-resolution is higher. For instance, periradicular osteolysis is more likely to be identified in panoramic images than in cone-beam scans. Contrarily, they contain a significantly lower level of overall-information compared to three-dimensional scans. Furthermore, they do not permit direct measurement of distances. The better resolution may be utile in terms of periodontal diagnosis. But concerning pre-operative planning of BRONJ-procedures, the determination of the exact size of a lesion might be more valuable. Future investigations may lead to safer pre-operative criteria on the necessary extend of resection.

Key words: bisphosphonate; BRONJ; cone-beam; computed-tomography; radiology