Bettina Hohlweg-Majert

Fluorescence-Guided Bone Resection in Bisphosphonate-Related Osteonecrosis of the Jaws: First Clinical Results of a Prospective Pilot Study

PURPOSE Surgical debridement is the therapy of choice in advanced stages of bisphosphonate-related osteonecrosis of the jaws (BRONJ). However, the therapy is currently only loosely standardized because no suitable imaging modalities exist. This study aims to redress this by exploring the suitability and reproducibility of applying a fluorescence-guided bone resection to patients with BRONJ. PATIENTS AND METHODS This prospective pilot study comprised 15 patients with 20 BRONJ lesions (only stages II and III) with a history of intravenous bisphosphonate treatment for metastatic bone diseases. Before surgical treatment, each patient received a 10-day administration of doxycycline. Fluorescence-guided resection of necrotic bone was performed by means of a certified fluorescence lamp. Success of the procedure was proclaimed if mucosal closure was observed and symptoms were absent 4 weeks postoperatively. RESULTS The 4-week postoperative follow-up identified a mucosal closure in 17 of 20 BRONJ lesions (85%). These patients were free of any symptoms. Failure as defined by mucosal dehiscence and exposed bone was observed in 3 of 20 BRONJ lesions (15%). CONCLUSION The success rate of this surgical regimen of BRONJ was respectable, and thus fluorescence-guided bone resection can be considered an effective treatment for stage II and stage III BRONJ. Furthermore, the reproducibility of the technique offers an opportunity to standardize the surgical therapy. Further studies are called for that compare the fluorescence-guided bone resection with conventional surgical approaches, as well as surgical versus conservative treatment in the early stages (stages 0 and I) of BRONJ.

The Role of Allogenic Amniotic Membrane in Burn Treatment

Amniotic membrane (AM) has been used in burns for nearly 100 years. The purpose of this article is to give a comprehensive review of the English literature published in the last two decades (1987–2007) to present the current state of this therapy form. Three medical databases (PubMed, Medline, The Cochrane Library) and specific burn journals were electronically screened for relevant articles using carefully selected retrieval strategies and keywords (AM, amnion grafts, burns, wound dressing, amnion banking). Bibliographies of relevant articles were analyzed for additional pertinent publications. After exclusion of articles which referred to the use of AM in reconstructive and ophthalmologic surgery, the inquiry yielded 31 relevant articles in English language dealing with AM and burns. There was no publication fulfilling the criteria of evidence level I, 6 articles had evidence level II, 10 had evidence level III, 6 had evidence level IV, and 9 were merely narrative (level V). The review testifies to—in view of good tissue practice—heightened use of processed AM in burns, especially in the last decade. Randomized clinical trials favored the use of amnion in burns in the first place for promotion of wound healing and in the second place for its comfortable and less dressing changes. Antimicrobial effects, pain relief, reduction of fluid, and scar formation were demonstrated additionally.

Navigational maxillofacial surgery using virtual models.

Ablative tumor surgery and orbital and midface reconstruction, as much as orthognathic surgery, requires detailed planning using computed tomography (CT) or magnetic resonance imaging (MRI). These techniques also allow simulation of complex surgeries preoperatively. Proper reconstruction depends on reliable information to choose the correct type of grafts and to predict the outcome. This study evaluates the benefit and indications of computer-assisted surgery in the treatment of 107 patients who underwent craniomaxillofacial surgery. Based on a CT or MRI data set, an optical navigation system was used for preoperative planning, intraoperative navigation, and postoperative control. Surgery could be preoperatively planned and intraoperatively navigated. Preoperatively, it required that soft and hard tissues were measured using the mirrored data set of the unaffected side; the size and location of the graft were chosen virtually. Intraoperatively contours of transplanted tissues were navigated to the preoperatively simulated reconstructive result. Computer-assisted treatment was successfully completed in all 107 cases. Preoperatively outlined safety margins could be exactly controlled during tumor resection. Reconstruction was designed and performed precisely as virtually planned. Image-guided treatment improves preoperative planning by visualizing the individual anatomy, outlining the intended reconstructive outcome, and by objectifying the effect of adjuvant therapy. Intraoperative navigation makes tumor and reconstructive surgery more reliable by showing the safety margins, saving vital structures, and leading the reconstruction to preoperatively planned objectives.

Morphometric analysis - Cone beam computed tomography to predict bone quality and quantity.

AIM Modified quantitative computed tomography is a method used to predict bone quality and quantify the bone mass of the jaw. The aim of this study was to determine whether bone quantity or quality was detected by cone beam computed tomography (CBCT) combined with image analysis. MATERIALS AND PROCEDURES: Different measurements recorded on two phantoms (Siemens phantom, Comac phantom) were evaluated on images taken with the Somatom VolumeZoom (Siemens Medical Solutions, Erlangen, Germany) and the NewTom 9000 (NIM s.r.l., Verona, Italy) in order to calculate a calibration curve. The spatial relationships of six sample cylinders and the repositioning from four pig skull halves relative to adjacent defined anatomical structures were assessed by means of three-dimensional visualization software. RESULTS The calibration curves for computer tomography (CT) and cone beam computer tomography (CBCT) using the Siemens phantom showed linear correlation in both modalities between the Hounsfield Units (HU) and bone morphology. A correction factor for CBCT was calculated. Exact information about the micromorphology of the bone cylinders was only available using of micro computer tomography. CONCLUSION Cone-beam computer tomography is a suitable choice for analysing bone mass, but, it does not give any information about bone quality.

Treatment perspectives for medication-related osteonecrosis of the jaw (MRONJ)

The medication-related osteonecrosis of the jaw (MRONJ) is believed to be a therapy-resistant entity. Although the application of the recommended conservative and surgical treatment regimens have returned variable success rates, the increased awareness and experience with MRONJ suggests that surgical therapy can halt the progression of the disease, thereby allowing a histology-based diagnosis of the osteonecrosis. Surgical treatment protocols can achieve success rates of over 90% and novel techniques such as the visualization of bone fluorescence can assist in the intra-operative delineation of the osteonecrosis and standardize the procedure.

Report of rare bilateral nasolabial cysts.

PURPOSE Nasolabial cysts are usually unilateral and are quite rare, while bilateral cysts are even rarer. PATIENT AND METHOD Our report concerns a 48-year-old female with bilateral nasolabial cysts. After many years of misdiagnosis she was finally referred to our clinic with a subnasal swelling of unknown origin. RESULT Evaluation of the patients medical history, clinical examination and of a previous CT scan led to the diagnosis of a nasolabial cyst, which was later confirmed by histological examination. Treatment involved the surgical excision. CONCLUSION A complete surgical excision is recommended using a sublabial approach as the treatment of choice, although transnasal endoscopic marsupialization seems to be a simple and effective alternative. It has been shown that after successful marsupialization, the nasolabial cyst is converted to an air-containing paranasal sinus.

Preoperative cervical lymph node size evaluation in patients with malignant head/neck tumors: comparison between ultrasound and computer tomography

PurposeThe spread of malignant lymph nodes due to malignancies of the head and neck is systematically observed. However, sentinel lymph nodes in the cervical region, such as in the axillary or supraclavicular regions, are not described. Therefore, precise preoperative lymph node screening of all neck compartments is required.Materials and methodsForty-five patients with a primary malignant tumor in the head and neck area underwent lymph node staging of the head by means of both CT and ultrasound as a preoperative evaluation. The lymph nodes were classified on the origin of the level system proposed by Som et al. (174:837–844, 2000), which is based on the recommendation of the American College of Radiology introduced in 1990. According to the manual measurement of World Health Organization and the Revised Response Evaluation Criteria in Solid Tumors, the longest transversal and longitudinal diameters were measured by ultrasound, while only the two longest transversal diameters were recorded by CT. The study was conducted by two independent observers. These results were compared with the histopathological results as references.ResultsSix hundred and twenty-four lymph nodes were detected, 64 of which were malignant. Most of the transformed lymph nodes were found in level IIa, II b and III. A more precise measurement was given using ultrasound. The correct positive rate of sonographically detected malignant lymph nodes was significantly higher compared to the CT reading.ConclusionCervical lymph node staging can be performed safely by ultrasound. It is a cheap, easy-to-handle and cost-effective diagnostic method. However, only the uppermost regions of the neck are accessible with a linear transducer. Despite this restriction, ultrasound is a reliable and valuable tool for screening lymph nodes in the case of a head or neck malignancy.

Effect of antiresorptive drugs on bony turnover in the jaw: denosumab compared with bisphosphonates.

Osteonecrosis of the jaw as a result of treatment with receptor activators of nuclear factor kappa-B ligand (RANKL) inhibitors (denosumab) is a new type of bony necrosis, the exact pathogenesis of which is unknown. Our aim was to find out whether the turnover of bone in the jaw is increased after denosumab has been given compared with other skeletal sites, and if that turnover might have a role in denosumab-related osteonecrosis of the jaw (DRONJ). Bone scintigraphic images of 45 female patients with breast cancer and bone metastases were analysed retrospectively, and divided into 3 groups: those given denosumab, those given a bisphosphonate, and a control group (n=15 in each). All patients had bone scintigraphy before treatment (T0) and during the course of treatment after 12 (T1) and 24 (T2) months. The data were analysed quantitatively using 6 preset bony regions of interest. There was similar turnover of bone in the mandible compared with other skeletal sites (such as the femur), while the maxilla showed significantly higher turnover. None of the bony regions investigated showed any significant changes after the bisphosphonate had been given. There was a tendency to increase bone turnover in those patients taking denosumab. The bone turnover of the jawbone is not overtly changed either by a bisphosphonate or denosumab, so it seems unlikely that oversuppression of bony turnover in the jawbones plays an important part either in the pathogenesis of DRONJ or in the bisphosphonate-related osteonecrosis of the jaw (BRONJ).

Sensitivity and Specificity of Oral Brush Biopsy

The aim of this study was to evaluate the advantage of computer-assisted analysis of the oral brush biopsy compared with synchronous scalpel biopsy in the early detection of oral lesions. In this prospective, randomized, controlled study, brush and scalpel biopsies were performed on 75 patients. Six patients had to be excluded due to inadequate results, and 43 were shown to have dysplastic epithelium, 15 carcinoma, and 11 suspicious lesions. Therefore, the sensitivity for the detection of abnormal cells by means of OralCDx was 52%, specificity 29%, and the positive predictive value 63%. According to our results, the use of oral brush biopsy as a standardized, minimally invasive method of screening oral lesions should be reconsidered.

Design and development of a virtual anatomic atlas of the human skull for automatic segmentation in computer-assisted surgery, preoperative planning, and navigation.

AbstractPurpose Manual segmentation of CT datasets for preoperative planning and intraoperative navigation is a time-consuming procedure. The purpose of this study was to develop an automated segmentation procedure for the facial skeleton based on a virtual anatomic atlas of the skull, to test its practicability, and to evaluate the accuracy of the segmented objects. Materials and methods The atlas skull was created by manually segmenting an unaffected skull CT dataset. For automated segmentation of cases via IPlan cranial (BrainLAB, Germany), the atlas skull underwent projection, controlled deformation, and a facultative threshold segmentation within the individual datasets, of which 16 routine CT (13 pathologies, 3 without) were processed. The variations of the no-threshold versus threshold segmentation results compared to the original were determined. The clinical usability of the results was assessed in a multicentre evaluation. Results Compared to the original dataset, the mean accuracy was