Lesions of the lateral pterygoid muscle-an overestimated reason for temporomandibular dysfunction: a 3T magnetic resonance imaging study.

The aim of this study was to examine the lateral pterygoid muscle (LPM) parenchyma, myotendinous junction, and tendon in temporomandibular disorder (TMD) patients using 3T magnetic resonance imaging (MRI). Results were compared with findings reported in the literature, in which the LPM has been attributed a major role in triggering TMD. 3T MRI was used for temporomandibular joint (TMJ) imaging. The MRI images of 63 patients were analysed for muscle contracture and atrophy, tendon rupture, signal alterations of the tendon, tendon contrast enhancement, and peritendinous fluid collection. Descriptive statistics and the coefficient estimate method were used for statistical analysis. Focus was placed on the association between LPM tendon pathology and TMJ lesions like osteoarthritis and disc displacement. Severe lesions of the LPM tendon and muscle parenchyma, like rupture or fibrosis, were detected in very few cases. Only moderate signs of tendinosis were found in TMD patients. In contrast, there was a clear correlation between tendon lesions and osteoarthritis or anterior disc displacement. These results indicate the need to discuss and question the role of the LPM and its tendon in TMD. Data suggest that LPM and tendon lesions are part of complex degenerative changes of the TMJ, and it seems less likely that a LPM disorder is causative in TMD.

Fluorescence imaging of invasive head and neck carcinoma cells with integrin αvß6-targeting RGD-peptides: an approach to a fluorescence-assisted intraoperative cytological assessment of bony resection margins.

We assessed the use of peptides containing arginylglycylaspartic acid (RGD) that target integrin αvß6 as a potential approach for a fluorescence-assisted intraoperative cytological assessment of bony resection margins (F-AICAB) in patients who had bone-infiltrating squamous cell carcinoma (SCC) of the head and neck. This was assessed to demarcate invasive carcinoma cells that stained for αvß6. Specimens from bony resection margins (n=362) were defined as either malignant or benign according to the results of cytological and histological examinations. Integrin αvß6-targeting fluorescence-labelled RGD peptides were added to the cytological samples and the accuracy of the resulting signal assessed by comparing it with the cytological findings. The value of F-AICAB was evaluated to find out if it could help to improve future diagnoses, tests, and treatments. Integrin αvß6 was strongly expressed in invasive SCC cells and qualified as a marker for bone-infiltrating carcinoma cells. It showed a high affinity to bind to invasive SCC cells and enabled swift and specific demarcation of αvß6-stained carcinoma cells. It was also diagnostic, with a sensitivity of 100% (95% CI 81.3% to 99.3%), specificity of 98.3% (95% CI 94.4% to 99.0%), positive predictive value of 92% (95% CI 70.2% to 94.3%), and negative predictive value of 100% (95% CI 96.9% to 99.9%), compared with the cytological findings. The targeting of specific integrin subtypes with selective, synthetic ligands, adapted for multimodal imaging, is a promising new approach to diagnosis. Further studies are necessary to provide more evidence for successful clinical translation and to establish the impact on clinical procedures.

Intraoperative cell isolation for a cytological assessment of bone resection margins in patients with head and neck cancer.

The intraoperative cytological assessment of bony resection margins (ICAB) is a feasible diagnostic approach to support frozen section for assessment of invasion of margins of soft and hard tissue. However, complex resection margins could challenge both diagnostic approaches. Our objective here was to identify the limitations of intraoperative diagnostic methods for assessing margins. We present an advanced cytological approach to assess complex margins that may solve the problem. Data from 119 patients in whom frozen section was supported by ICAB, were reviewed and the reasons for false results analysed. In 35 patients with squamous cell carcinoma infiltrating bone, specimens (n=100) from the resection margin went through an intraoperative cell isolation process for the cytological assessment of bony margins (ICAB). The results were compared with the histological results of the corresponding margins of bone as a reference. Limitations to the assessment of operative bony margins intraoperatively included an infiltrative histological pattern of growth of the carcinoma, with carcinoma cells disseminated within the cancellous bone, complex and uneven resection margins with soft and bony tissue, inflammation, and signs of previous radiotherapy. Intraoperative cell isolation plus (ICICAB) allowed the microscopic assessment of up to 1cm3 of bony tissue to detect disseminated carcinoma cells within the cancellous bone with a sensitivity of 92.3% (95% CI 74.9% to 99.1%), and a specificity of 100% (95% CI 95.1% to 100%), and positive and negative predictive values of 100% (95% CI 85.8% to 100%) and 97.4% (95%CI 90.8% to 99.7%), respectively. Intraoperative cell isolation is a feasible new technique to support ICAB and frozen section in the assessment of bony and soft tissue margins.

Radiotherapy for oral cancer decreases the cutaneous expression of host defence peptides.

INTRODUCTION: Bacterial resistance against antibiotics has become an increasing challenge in the treatment of cutaneous infections. Consequences can be severe, especially in infected wounds following previous local radiotherapy. Certain endogenous peptide antibiotics, the host defence peptides (HDPs), exhibit broad-spectrum antimicrobial activity and promote wound healing. Their use as supplements to conventional antibiotics is a current topic of discussion; however, knowledge of their quantities in healthy and compromised tissue is a prerequisite for such discussion. To date, no data concerning HDP quantities in irradiated skin are available. METHODS: Expression profiles of the genes encoding HDPs, namely human beta-defensin-1 (DEFB1, hBD-1), beta-defensin-2 (DEFB4A, hBD-2), beta-defensin-3 (DEFB103, hBD-3) and S100A7, were assessed in samples of non-irradiated and irradiated neck. RESULTS: A reduction in the expression of all of the examined genes was observed in irradiated skin when compared with non-irradiated skin (statistically significant in the case of S100A7, P = 0.013). Immunohistochemistry revealed differences in HDP distribution with respect to the epithelial layers. CONCLUSION: The study demonstrates a significant reduction in HDP gene expression in neck skin as a result of radiotherapy. These findings might represent a starting point for novel treatments of cutaneous infections in irradiated patients, such as topical supplementation of synthetic HDP.