Sebastian Hoefert

Importance of microcracks in etiology of bisphosphonate-related osteonecrosis of the jaw: a possible pathogenetic model of symptomatic and non-symptomatic osteonecrosis of the jaw based on scanning electron microscopy findings

The aim of this study was to evaluate a possible role of microcracks in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (ONJ) and to discuss an etiological model. Bone samples from 35 patients with ONJ were analyzed. Control samples were taken from five patients with osteomyelitis (OM), ten patients with osteoradionecrosis, seven patients with osteoporosis and bisphosphonate medication without signs of ONJ, and six osteoporotic elderly patients. Samples were examined using scanning electron microscopy. In 54% of the bone samples of patients with ONJ, microcracks were seen. Inflammatory and connective tissue reactions within the microcracks were evident in 82% of the cases, indicating that these cracks were not artificial. In contrast, only 29% of samples from patients with oral bisphosphonate medication without ONJ, no sample from patients with OM, none of the osteoradionecrosis group, and only 17% from patients with osteoporosis showed microcracks. Statistically significant differences could be found between the ONJ group and the group after irradiation and the group with OM, respectively. The evidence of microcracks could be a first step in the pathogenesis of bisphosphonate-related ONJ. The accumulation of these microcracks leads to a situation that could be named “non-symptomatic ONJ”. Disruptions of the mucosal integrity may then allow bacterial invasion, leading to jawbone infection with exposed bone, fistulas, and pain. This state could be called “symptomatic ONJ”. Furthermore, an assumed local immunosuppression as indicated by various studies could explain the severe courses of therapy-resistant ONJ as regularly observed.

Sunitinib may raise the risk of bisphosphonate-related osteonecrosis of the jaw: presentation of three cases

OBJECTIVE Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a serious side effect of bisphosphonate (BP) medication. Tooth extractions are the most frequent causes for BRONJ. In some cases BRONJ is observed spontaneously, with some anatomic sites carrying a higher risk. Sunitinib, a tyrosine kinase inhibitor, is established in renal cell carcinoma and is known to lead to oral mucositis as a side effect, which in BP patients may additionally raise the risk of BRONJ. STUDY DESIGN We present 3 patients with renal cell carcinoma under BP medication who developed BRONJ during and after sunitinib medication. RESULTS In 2 patients, BRONJ was linked to the occurrence of mucositis after sunitinib intake. The third patient showed relapse of completely healed BRONJ lesions shortly after resumption of a sunitinib therapy. CONCLUSIONS Oral mucositis during chemotherapy may raise the risk of BRONJ in cancer patients with BP medication. Especially in renal cell carcinoma patients under sunitinib therapy and intravenous BP medication, oral mucositis should be observed closely because it could be a risk factor for BRONJ.

Relevance of a Prolonged Preoperative Antibiotic Regime in the Treatment of Bisphosphonate-Related Osteonecrosis of the Jaw

PURPOSE Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a severe and therapy-resistant disease. The present study was performed to evaluate the role of the duration of preoperative antibiotic therapy within an otherwise standardized treatment protocol of patients with BRONJ stages I and II. One group of patients received a short-term preoperative antibiotic regime (A-ST) and the other a long-term preoperative antibiotic regime (B-LT). PATIENTS AND METHODS A retrospective chart review was used to analyze 46 patients with BRONJ from 2004 to 2009 who were treated with the same surgical technique and the same postoperative antibiotic treatment. Ten patients were classified as stage I, and 37 as stage II. All patients had intravenous bisphosphonate therapy in their case histories. Surgical treatment included an extended surgical procedure with sequestrectomy, bone smoothing, tension-free tissue covering, and drainage, with attention to neighboring teeth. After surgery, antibiotics were given (median) for 7 days intravenously and orally for another 10 to 12 days. Only patients who fulfilled these criteria were included in the retrospective chart review. In group A-ST 16 patients with 17 operations received antibiotics for 1 to 8 days before operation, whereas in group B-LT 30 patients had preoperative therapy of 23 to 54 days. Postoperative clinical examination followed a standardized protocol. Complete healing with intact soft tissue coverage was regarded as a success. RESULTS The mean follow-up in both groups was 17.4 months (median, 11.5 months). Within the overall observation period, only 35% of patients in group A-ST and 70% in group B-LT showed complete healing, but at the time of the last clinical examination, 53% in group A-ST and 87% in group B-LT were free of soft tissue dehiscence. A certain number of soft tissue dehiscences within the observation period could clearly be related to later tooth extractions or pressure sores of dentures; excluding these interfering problems, 47% in group A-ST and 87% in group B-LT were treated successfully. Differences between these groups were significant. CONCLUSIONS This study indicates that surgical treatment in patients with stage I BRONJ and especially in those with stage II BRONJ in combination with a long-term preoperative antibiotic treatment can lead to a complete healing in 70% to 87% of cases in contrast to 35% to 53% with a short-term regime. The higher success rate after prolonged preoperative antibiotic therapy may be linked to an infectious role in BRONJ etiology requiring adequate treatment. Antibiotics may effectively treat neighboring lightly infected bone, whereas surgery removes the irreversibly infected and necrotic bone. To achieve complete healing, an extended surgical procedure in combination with local mouth rinses and prolonged antibiotic therapy can be recommended for treatment of BRONJ.

ABCB5 expression and cancer stem cell hypothesis in oral squamous cell carcinoma

INTRODUCTION The vast majority of oral cancers are squamous cell carcinomas (OSCC). The effectiveness of adjuvant cytostatic chemotherapy for OSCC is frequently restricted due to an inducible cellular mechanism called multidrug resistance (MDR) and a putative cancer stem cell (CSC) compartment in human carcinogenesis expressing multidrug efflux pumps. The novel human ATP-binding cassette (ABC) transporter ABCB5 [subfamily B (MDR/TAP) member 5] acts as an energy-dependent drug efflux transporter and marks tumour cells of a putative CSC compartment. However, to date, there is no link between ABCB5 expression and OSCC. MATERIALS AND METHODS Expression of ABCB5 was analysed in OSCC specimen (n=191) and cancer cell lines (BICR3, BICR56) by immunohistochemistry, real-time polymerase chain reaction (RT-PCR) analysis and western blotting. Scanned images were digitally analysed using ImageJ and the immunomembrane plug-in. ABCB5 expression on protein level was correlated with clinical characteristics and impact on survival. ABCB5 was co-labelled with CD44 in immunohistochemical and immunofluorescence double labelling experiments. Expression subgroups were identified by receiver operating characteristics (ROC) analysis. RESULTS High ABCB5 expression was significantly associated with tumour progression and recurrence of the tumour. Multivariate analysis demonstrated high ABCB5 expression as an independent prognostic factor (p=0.0004). Immunohistochemical and immunofluorescence double labelling experiments revealed ABCB5 expression by CD44+ cancer cells. ABCB5 specificity was confirmed by western blot and RT-PCR analysis. CONCLUSIONS For the first time, this study provides evidence that ABCB5 expression in OSCC might be associated with tumour formation, metastasis and a putative CSC compartment. One of the principal mechanisms for protecting putative cancer stem cells is through the expression of multifunctional efflux transporters from the ABC gene family, like ABCB5. This provides one mechanism in which putative cancer stem cells could survive and may lead to tumour relapse. Knowledge of expression profiles of ABC transporters and other genes involved in MDR will likely help therapeutic optimisation for cancer patients in clinic. However, this hypothesis requires further in vitro and in vivo studies.

Macrophages and bisphosphonate-related osteonecrosis of the jaw (BRONJ): evidence of local immunosuppression of macrophages in contrast to other infectious jaw diseases

ObjectivesBisphosphonates (BIP) are well established in bone diseases. A serious side effect is the bisphosphonate-related osteonecrosis of the jaw (BRONJ). Among different aetiology factors, local suppression of immune functions is gaining interest. The aim of this study was to analyze the function of macrophages in BRONJ in contrast to patients with osteoradionecrosis (ORN) and secondary chronic osteomyelitis (OM) of the jaws. Samples were also taken from patients with bisphosphonate medication (BP) without signs of infection, radiation therapy (RA), and osteoporosis (OP) as controls.Material and methodsOne hundred five patients with surgery to the jaw were included in this study: 33 patients with BRONJ, 17 with ORN, 11 with secondary chronic OM, 8 with RA, 25 with BP medication and 11 with OP. Samples were histologically analysed and monocytes/macrophages stained using CD14 and CD68. The number of positively marked cells was counted per view (pv), and the CD68/CD14 ratio was calculated. Statistically, the Naïve-Bayes and decision-tree classifier were used.ResultsThe number of CD14 positive cells was 10.3 cells/pv in the BRONJ-group in as compared to 5 in the ORN- and 3.8 in the OM-group respectively. The number of CD68 positive cells was 11.4/pv (BRONJ-group) as compared to 14/pv (ORN-group) and 12.7/pv (OM-group). With 0.89, the BRONJ-group showed a statistically different CD68/CD14 ratio than ORN-group with 3.39 and OM-group with 3.03.ConclusionsOur results indicate a different expression of CD14 and CD68 markers of monocytes/macrophages in BRONJ as compared to other jaw infections. This could be a sign of macrophage immunosuppression by BPs. In contrast, patients receiving BP medication without BRONJ showed no differences to other controls.Clinical relevanceThis is the first study that clinically indicates a compromised macrophage function at BRONJ sites in contrast to ORN or secondary OM sites. The BRONJ itself could be forwarded by this effect.

Implementing a Superimposition and Measurement Model for 3D Sagittal Analysis of Therapy-induced Changes in Facial Soft Tissue: a Pilot Study

Aim:3D digital surface photogrammetry is an objective means of documenting the quantitative evaluation of facial morphology. However, there are no standardized superimposition and measurement systems for surveying soft tissue changes. The aim of this study was to present a superimposition and measurement model for three-dimensional analysis of therapy-induced sagittal changes in facial soft tissue and to ascertain its applicability based on the reproducibility of 3D landmark positions.Patients and Method:Twenty-nine children were examined (eight with cleft lip and palate, six with cleft palate, eight with Class III malocclusion and seven healthy controls, between 4.1 and 6.4 years). The mean time between examinations was 8.2 months for the patients and 8 months for the control group. Data was acquired with the DSP 400©imaging system. A mathematical model with seven superimposition points was developed. Two 3D images, one at the beginning and the other at the end of the examination, were generated. Both images were superimposed ten times. Ten landmarks for evaluating the soft tissue changes were geometrically defined on the superimposition image, put in place ten times, and measured. The landmarks’ reproducibility was calculated via statistical intraoperator analysis. Measurement error was identified using the root mean square error (RMSE).Results:The superimposition points were easy to locate and the landmarks well definable. All midface landmarks proved to be highly reproducible with an RMSE under 0.50 mm. The lower face landmarks demonstrated good reproducibility with an RMSE under 1 mm. The midface landmarks’ precision fell below the range of accuracy, while the lower face landmarks’ precision fell within the optoelectronic scanner device’s range of accuracy (0.50–1 mm).Conclusions:As an accurate, non-invasive, millisecond-fast, non-ionizing and ad infinitum repeatable procedure, 3D digital surface photogrammetry is very well suited for clinical and scientific application in orthodontics. We developed a reliable superimposition and measurement model with 3D digital surface photogrammetry. This new capturing and measurement system provides a simple means of determining 3D changes in facial soft tissue. Our landmarks proved to be highly reproducible for the midface while revealing good reproducibility for the lower face.ZusammenfassungZiel:Die digitale 3D-Oberflächenphotogrammetrie stellt ein objektives Verfahren dar, um die Gesichtsmorphologie quantitativ zu erfassen. Standardisierte Überlagerungs- und Auswertungsmodelle zur Vermessung von Weichteilveränderungen fehlen jedoch. Ziel dieser Studie war es, ein Überlagerungs- und Auswertungsmodell zur dreidimensionalen Analyse von therapiebedingten sagittalen Gesichtsweichteilveränderungen zu entwickeln und dessen Anwendbarkeit anhand der Reproduzierbarkeit der 3D-Landmarkenpositionierung zu überprüfen.Patienten und Methodik:Es wurden 29 Kinder, acht mit LKGSpalten, sechs mit Gaumenspalten, acht mit Klasse-III-Anomalien und sieben gesunden Kontrollen, zwischen 4,1 und 6,4 Jahren untersucht. Das Untersuchungsintervall betrug 8,2 Monate für die Patienten und 8 Monate für die Kontrolle. Die Datenakquisition erfolgte mit dem DSP-400©-System. Es wurde eine mathematische Konstruktion mit sieben Überlagerungspunkten entwickelt. Zwei 3D-Bilder, zum Untersuchungsbeginn und Untersuchungsende, wurden generiert und zehnfach überlagert. Auf dem Überlagerungssummenbild wurden zehn Messpunkte zur Erfassung der Weichgewebeveränderungen geometrisch bestimmt, zehnfach platziert und vermessen. Die Reproduzierbarkeit der Messpunkte wurde mit einer statistischen Intraoperatoranalyse überprüft. Der Messfehler wurde mit dem „Root Mean Square Error“ (RMSE) berechnet.Ergebnisse:Die Überlagerungspunkte ließen sich gut auffinden und die Messpunkte im Anschluss gut definieren. Alle Mittelgesichtspunkte zeigten eine hohe Reproduzierbarkeit mit einem RMSE kleiner als 0,50 mm. Die Untergesichtspunkte waren mit einem RMSE kleiner als 1 mm gut reproduzierbar. Die ermittelte Präzision der Mittelgesichtspunkte lag somit unterhalb und die der Untergesichtspunkte innerhalb der Genauigkeit des optoelektronischen Scanners (0,50–1 mm).Schlussfolgerungen:Als genaues, nichtinvasives, millisekundenschnelles, strahlenfreies und ad infinitum wiederholbares Verfahren ist die digitale 3D-Oberflächenphotogrammetrie sehr gut für den klinischen und wissenschaftlichen Einsatz in der Kieferorthopädie geeignet. Ein zuverlässiges Überlagerungs- und Auswertungssystem konnte mit der angewandten digitalen 3D-Oberflächenphotogrammetrie eingeführt werden. Es handelt sich um eine einfache Methode, faziale Weichteilveränderungen zu ermitteln. Die Messpunkte zeigten eine hohe (Mittelgesichtsbereich) bis gute (Untergesichtsbereich) Reproduzierbarkeit.

Kieferknochennekrosen als mögliche unerwünschte Wirkung von Bisphosphonaten

Bisphosphonate werden in der Therapie von Tumorpatienten mit Hyperkalzämie, Knochenmetastasen oder auch in der Osteoporosetherapie angewendet. In der letzten Zeit gibt es Hinweise auf mögliche Nebenwirkungen im Sinne von therapieresistenten Nekrosen im Kieferbereich. Offizielle Stellen der Arzneimittelkommissionen haben im Deutschen Ärzteblatt und in der Deutschen Apothekerzeitung auf die Möglichkeit dieser Nebenwirkung hingewiesen. In unserer Behandlung befinden sich sieben Patienten mit therapieresistenten Osteonekrosen des Kiefers unter Bisphosphonattherapie. Die Darstellung dieser Fälle soll auf diese klinisch sehr bedeutsame mögliche unerwünschte Wirkung hinweisen. Bisphosphonates are widely used in the treatment of cancer patients with hypercalcemia and bone metastases or in osteoporosis therapy. Current reports have focused on therapy-resistant osteonecrosis of the jaws as a possible side effect of bisphosphonates. Official German drug committees have recently warned about the possibility of these side effects in the publication organs Deutsches Ärzteblatt and Deutsche Apotheker Zeitung. So far we have had experience with seven patients showing therapy-resistant osteonecrosis of the mandible under bisphosphonate medication. The presentation of these cases is intended to call attention to this clinically important side effect of bisphosphonate medication.

Standardized pretreatment inflammatory laboratory markers and calculated ratios in patients with oral squamous cell carcinoma

Analyzing the inflammatory microenvironment has become an important issue in the management of oral squamous cell carcinoma (OSCC). Pretreatment C-reactive protein (CRP) levels, leucocytes, monocytes, lymphocytes, neutrophils, basophils, eosinophils, platelets, neutrophil-to-lymphocyte ratio (NLR), derived NLR (dNLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) derived from the peripheral blood were analyzed. Receiver operating characteristic (ROC) curves determined a cut-off value for each parameter in 146 patients with OSCC compared with 93 controls and the results were associated with clinicopathological characteristics. CRP expression of tumors was measured by immunohistochemistry. ROC analysis determined cut-off values for CRP levels, leucocytes, monocytes, lymphocytes, neutrophils, NLR, dNLR, LMR, PLR and showed significant differences between the OSCC and control group. Compared with single laboratory tests calculated ratios were superior in measuring sensitivity and specificity of OSCC disease. NLR was significant directly associated and correlated with PLR. LMR was significant inversely associated and correlated with NLR and PLR. Immunohistochemical analysis did not show CRP expression of OSCCs. This study highlights the first analysis for cut-off values of pretreatment single laboratory tests and calculated ratios, which are strongly needed for a follow-up of cancer patients. Additionally, the calculated baselines can be used as a goal for successful immunotherapies in the future. The links between NLR, LMR, and PLR might be helpful for the clinical course (monitoring) of cancer patients and have been first described for OSCC in this study. Taken together, analyzing these data provides an additional practical guideline of further postoperative OSCC management.

Effect of bisphosphonates on macrophagic THP-1 cell survival in bisphosphonate-related osteonecrosis of the jaw (BRONJ)

OBJECTIVES Immune deficiency and bacterial infection have been suggested to play a role in the pathophysiology of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Zoledronate was previously found to promote THP-1 cell death. To examine this hypothesis with all commonly prescribed bisphosphonates, we tested the effect of (nitrogen-containing) ibandronate, risedronate, alendronate, pamidronate, and (non-nitrogen-containing) clodronate on macrophagic THP-1 cells. STUDY DESIGN Activated THP-1 cells were exposed to .5 to 50 μM of nitrogen-containing bisphosphonates and .5 to 500 μM of clodronate. Cell adherence and survival were assessed in vitro using the xCELLigence real-time monitoring system. Results were confirmed histologically and verified with Live/Dead staining. RESULTS All bisphosphonates inhibited THP-1 cell adherence and survival dose and time dependently, significant for zoledronate, alendronate, pamidronate, and clodronate in high concentrations (50 μM and 500 μM; P < .05). Low concentrations (0.5 μM) of risedronate, alendronate, and pamidronate prolonged the inflexion points of THP-1 cell survival compared with controls (P < .05). THP-1 cells exhibited no cytomorphologic changes at all concentrations. CONCLUSIONS Commonly prescribed bisphosphonates inhibit the survival of macrophagic THP-1 cells dose-dependently without altering morphology. This may suggest a local immune dysfunction reflective of individual bisphosphonate potency leading to the pathogenesis of BRONJ.

Amyloidose der Zunge als diagnostisch richtungsweisende Manifestation des Plasmozytoms

Das plasmozytische Non-Hodgkin-Lymphom ist der häufigste Tumor von Knochenmark und Knochen, der in der Regel über seine Kardinalsymptome monoklonale Paraproteinämie, Proteinurie, Anämie und Hyperkalzämie diagnostiziert wird. Amyloidablagerungen werden im weiteren Verlauf in fast allen Organen beobachtet. Plasmozytome, die über eine primär unklare Makroglossie diagnostiziert werden, stellen jedoch eine Seltenheit dar. In diesem Fallbericht wird eine 61jährige Patientin vorgestellt, die über eine persistierende Zungenschwellung mit schmerzhaften Ulzerationen klagte. Eine Probeexzision führte zur Diagnose einer primär systemischen Amyloidose vom Leichtkettentyp (AL) aufgrund eines Leichtkettenplasmozytoms vom Typ Ig-λ im Stadium II nach Durie und Salmon. Im weiteren Krankheitsverlauf entwickelte die Patientin zusätzlich Amyloidablagerungen im gesamten Gastrointestinaltrakt. Makroglossien als Frühsymptom eines Plasmozytoms werden in der zur Einsicht stehenden Literatur selten beschrieben, wogegen regelmäßig über Amyloidablagerungen im Bereich der Zunge bei länger bestehender Krankheit berichtet wird. Plasmocytic non-Hodgkin’s lymphoma is the most common tumor of bone and bone marrow, typically diagnosed by symptoms such as monoclonal paraproteinemia, proteinuria, anemia and hypercalcemia. In its progress, deposits of amyloids in almost all organs can be observed. However, plasmacytomas which are diagnosed by macroglossia of primarily unknown etiology are rare. This case report presents a 61-year-old woman who suffered from a persistent swelling of the tongue with painful ulcerations. A biopsy led to the diagnosis of primary systemic amyloidosis of the light-chain type, which subsequently proved to be a plasmacytoma with lambda light-chains stage II after Durie and Salmon. In the course of the disease the patient developed further deposits of amyloids in the whole gastro-enteric system. Macroglossia as a primary manifestation of plasmacytoma is rarely described in medical literature. However, reports on deposits of amyloid in the tongue in advanced stages of disease are well known.