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Objectives Histology is still regarded as the gold-standard to determine bone implant contact (BIC) as a parameter representing implant stability. As the further processing of cut slices for contact radiography (CR) to stained and polished histological sections is time consuming and error prone, our aim was to assess agreement between CR and Giemsa-eosin (GE) stained sections with regard to dental implants. Study Design Threaded dental titanium implants (n = 54) from the maxillae of Goettingen minipigs were evaluated. After 28 and 56 days, BIC and the ratio of bone volume to total volume (BV/TV; 1000 μm) were determined on the same sections by using CR and GE staining, and the results were compared. Results Moderate differences for BIC (0.6%; P = .53) and BV/TV (1.3%; P = .01) between the methods were determined, in which CR overestimated BIC and BV/TV. A strong correlation was seen between the modalities concerning BIC (28 days: r = 0.84; 56 days: r = 0.85; total: r = 0.85) and BV/TV (r = 0.96; r = 0.94; r = 0.96; all: P Conclusions CR enabled determination of the bone-to-implant interface in comparison with GE-stained sections. BIC and BV/TV were slightly overestimated but correlated strongly between the methods. Therefore, if BIC and BV/TV are sufficient endpoints, CR is adequate and no further preparation and staining are necessary.

Objective Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious side-effect of bisphosphonate therapy. In the majority of cases BRONJ occurs in the mandible. As a consequence a detailed investigation of BRONJ of the maxilla and in particular of involvement of the maxillary sinus has largely so far been neglected. The aim of this study was to analyse the frequency of maxillary sinusitis and oro-antral fistulae in BRONJ of the maxilla. Subjects and methods A retrospective multicentre analysis was carried out in three Departments of Oral and Maxillofacial Surgery focussing on patients suffering from BRONJ in the maxilla. The role of involvement of the maxillary sinus, in particular sinusitis and oro-antral fistula, was analysed. Results Out of a total of 170 patients suffering from BRONJ 53 cases (31.2%) with involvement of the maxilla were identified. At least one sign of maxillary sinusitis was present in 43.6% (23/53) and an oro-antral fistula in the course of the disease was detected in 35.8% (19/53) of those patients. The mean length of time of bisphosphonate intake was 36.16 ± 16.32 months. Zoledronate was most frequently associated (60.4%) with symptoms, followed by the combination of Zoledronate/Ibandronate (13.2%), and Zoledronate/Pamidronate or Pamidronate alone (both 7.5%). Conclusion Maxillary sinusitis and oro-antral fistulae are associated with a BRONJ manifestation in the upper jaw in approximately 44%. The involvement of the maxillary sinus should be given special attention and three-dimensional imaging modalities might be necessary, not only to evaluate the extent of necrosis, but also to exclude involvement of the maxillary sinus.

Purpose Differential diagnosis of osteoradionecrosis and bisphosphonate-related osteonecrosis of the jaw is primarily based on medical history, rather than pathogenesis or histopathology. This report aims to redress this shortcoming by demonstrating the advantages of tetracycline bone fluorescence as an aid to characterize osteonecrosis entities according to differential histopathologies. Furthermore, this technique facilitates the means to determine extent of necrosis and to optimize surgical therapy. Patients and Methods Two patients with extended osteonecrosis of the lower jaw (osteoradionecrosis or bisphosphonate-related osteonecrosis of the jaw) were treated with partial mandibulectomy. After preoperative administration of doxycycline for 10 days, bone fluorescence was monitored intraoperatively to determine the resection boundaries. Results Fluorescence analysis correlated well with the specific histopathologic features of the 2 osteonecrosis entities. Bone fluorescence was predominantly observed in the cortical bone and cancellous bone regions in osteoradionecrosis and bisphosphonate-related osteonecrosis of the jaw, respectively. Margins of the osteonecrosis (and the resection) could be determined under fluorescence guidance; however, bone bleeding did not correlate with bone fluorescence in both osteonecrosis entities. Conclusions Given that viable but not necrotic bone displays tetracycline fluorescence, a notion that reflects the histopathology, more precise characterization of the 2 osteonecrosis types is enabled. Furthermore, even in extended cases of osteonecrosis requiring partial mandibulectomy, bone fluorescence helps to pinpoint the margins of resection and thus signifies an improvement of surgical therapy of extended osteonecrosis.