Matthias Zirk

Clinical and histopathological staging in oral squamous cell carcinoma - Comparison of the prognostic significance.

BACKGROUND In oral cancer the prognostic significance of clinical staging (cTNM) is regarded inferior to histopathologic staging (pTNM) after surgery. This is mainly due to the point that the quality of the cTNM strongly depends on the clinical and radiological examination techniques applied and the physicians experience. The aim of this study was to evaluate the prognostic quality of cTNM and pTNM in a single center cohort. METHODS This retrospective study included 392 patients with treatment-naive oral squamous cell carcinoma (OSCC). All patients received primary surgery including a neck dissection. According to tumor stage and histopathologic risk factors patients received adjuvant radiotherapy (RT) or radiochemotherapy (RCT). Prognostic factors were identified in univariate analysis by using the log rank test and in multivariate analysis through Cox regression. RESULTS Clinical and histopathologic staging showed concordance in 62% for the primary tumor and 59% for cN- and pN-classification. In 58% of the cases of discordance the primary tumor was overstaged. In case of discordance of metastatic spread to the cervical lymph nodes, lymph node involvement showed overstaging in 78%. In univariate analysis cT-, cN-, cT- and pT-classification had a significant impact (p<0.05) on overall survival (OS). In multivariate analysis only pT- and pN-classification had a significant impact on OS. CONCLUSION Despite advances and modern radiologic techniques, pTNM has a higher prognostic quality than cTNM. Discordance between clinical and histopathologic staging was observed in up to 40%. When discordance was observed overstaging for clinical T-stage and clinical N-stage was more likely than understaging.

Three-dimensional fracture pattern analysis of the Obwegeser and Dal Pont bilateral sagittal split osteotomy.

The Obwegeser and Dal Pont modification of the bilateral sagittal split osteotomy (BSSO) is a well-established procedure in orthognathic surgery. The purpose of this retrospective study was to analyze the actual fracture patterns achieved with BSSO by Obwegeser and Dal Pont modification using postoperative cone beam computed tomography (CBCT) datasets from 100 patients. A total of 200 split osteotomies were assessed, which could be categorized into nine different split patterns. Only one of the observed split fractures (0.5%) followed exactly the fracture line described by Obwegeser and Dal Pont, whereas 40% followed the fracture line according to the Hunsuck and Epker modification and 13.5% were seen as unfavourable splits mainly running over the buccal plate. A significant correlation was found between unfavourable buccal splits and both horizontal osteotomies reaching the buccal surface at the dorsal ramus (P=0.001) and a vertical caudal bone cut end at the corpus with a buccal position (P<0.001). These results show that a complete antero-posterior horizontal osteotomy at the mandibular ramus does not lead to the intended fracture pattern, which rebuts the argument of a greater amount of bony overlap using the Obwegeser and Dal Pont modification.

Expression of ezrin in oral squamous cell carcinoma: Prognostic impact and clinicopathological correlations.

INTRODUCTION There have been few investigations into the effects of ezrin expression in oral squamous cell carcinoma (OSCC). The aim of this study was to analyze the influence of ezrin expression on the prognosis of patients with OSCC. MATERIALS AND METHODS Eighty patients were included in the retrospective study. Expression and localization of ezrin were evaluated using immunohistochemistry. Associations were identified using χ² tests. Prognostic factors were identified by univariate and multivariate analysis. RESULTS Seventy-six (95%) patients showed ezrin expression. Ezrin expression had a significant impact on overall survival (OS) (p < 0.001). With increasing expression, the 5-year OS rate dropped from 100% for ezrin-negative patients to 47% for patients with high expression. Multivariate analysis confirmed the significant influence of ezrin expression on OS (p = 0.011). Cytoplasmic localization of ezrin led to a significantly lower survival rate in comparison with membranous expression. CONCLUSIONS Ezrin may serve as a biomarker that predicts biologically aggressive behavior of OSCC and hence improves therapeutic techniques and the prognosis of patients affected with the disease.

Laterocaudal approach to the inferior rim of the orbit

PURPOSE Fractures of the orbital floor and orbital rim are frequently treated in maxillofacial departments. Various approaches to the orbital floor are described in the literature. We present an investigation of a modified subciliary approach (laterocaudal approach) with respect to its feasibility and clinical outcome. MATERIALS AND METHODS Our retrospective study investigated 130 well-documented cases of patients with orbital floor fractures who received surgical reconstruction using a laterocaudal approach, and compared the results with the current literature, with a focus on subciliary and transconjunctival approaches. RESULTS 111 patients (85.4%) presented a Vancouver scar scale (VSS) of 0.14 patients (10.8%) had a VSS score of 1. No patients had a VSS of 2. Just five patients (3.8%) had a slight ectropium and therefore a VSS score of 3. CONCLUSION The laterocaudal approach can be safely performed and presents advantages over comparable techniques such as the subciliary and transconjunctival approaches if performed correctly.

Microbial diversity in infections of patients with medication-related osteonecrosis of the jaw

ObjectivesA central role of infections in the treatment of MRONJ patients is widely accepted. An investigation of the MRONJ lesions’ biofilms as potential pathogens seems logical.Materials and methodsWe investigated the clinical data of our MRONJ patients who received surgery in advanced stage of the disease. Special attention was granted to the local colonizers harvested from osseous MRONJ specimens and submucosal putrid infections.ResultsEleven out of 71 patients presented a spontaneous onset of the disease and for 60 out of 71 patients a trigger was detected. Breast cancer (29.6%) and prostate cancer (22.5%) were the most frequent underlying disease for prescription of an antiresorptive therapy, mostly zoledronate. Submucosal soft tissue biofilms significantly differed from biofilms harvested from the MRONJ lesions bottom, yet the most frequent bacteria were equally present in both groups: Streptococcus species (spp.), Prevotella spp., Actinomyces spp., Veillonella spp., and Parvimonas micra. The cephalosporins, cefuroxime and cefotaxime, and ß-lactam antibiotics with ß-lactamase inhibitor revealed the greatest susceptibility for the detected bacteria.ConclusionThe bacteria from the submucosal areas and the bottom of the infected bone presented comparable susceptibility to the common antibiotics regimes. Streptococcus spp., Prevotella spp., and Veillonella spp. present a high abundance in MRONJ lesions beside Actinomyces spp. The MRONJ lesions bottom is in many cases not infected by Actinomyces spp.Clinical relevanceThe removal of the necrotic bone reduces the variety of bacteria found in MRONJ lesions, in particular at the bottom of the lesion.

Distance-dependent accuracy in Le Fort I maxillary repositioning procedures

It has been hypothesised that, in maxillary repositioning procedures, longer distances correlate with less accurate transfers and particularly the repositioning forces of facial skin and muscles that increase exponentially. However, this has not to our knowledge been confirmed. The purpose of this study was to search for differences in the accuracy of transfer from maxillary repositioning procedures parallel to the three orthogonal planes and with respect to three different anatomical landmarks of the first molar left and right (M1L and M1R) and the first incisor (I). Cone-beam computed tomography (CT) datasets taken before and after operation for 92 patients who had Le Fort I maxillary repositioning procedures were aligned to measure the changes in the maxillary position in the axial, sagittal, and transverse directions. Differences between planned distances and those achieved were calculated and analysed with Pearsons correlation coefficient. The strongest significant correlations between the extent of planned repositioning distances and achieved differences (error) were detected in the sagittal plane for the anatomical landmarks of the right (M1R) and left first molar (M1L). Correlations became weaker if a limited planned distance ranging from 0-4mm was compared with a complete observed range that reached up to 12mm. Our results show for the first time to our knowledge that the accuracy of transfer of wafer-based maxillary positioning procedures depends on the distance being moved. Longer distances correlate with less accuracy, particularly in the sagittal plane and in the first molar region.