Background:Lymph node density (LND) has previously been reported to reliably predict recurrence risk and survival in oral cavity squamous cell carcinoma (OSCC). This multicenter international study was designed to validate the concept of LND in OSCC.Methods:The study included 4254 patients diagnosed as having OSCC. The median follow-up was 41 months. Five-year overall survival (OS), disease-specific survival (DSS), disease-free survival (DFS), locoregional control and distant metastasis rates were calculated using the Kaplan–Meier method. Lymph node density (number of positive lymph nodes/total number of excised lymph nodes) was subjected to multivariate analysis.Results:The OS was 49% for patients with LND⩽0.07 compared with 35% for patients with LND>0.07 (P<0.001). Similarly, the DSS was 60% for patients with LND⩽0.07 compared with 41% for those with LND>0.07 (P<0.001). Lymph node density reliably stratified patients according to their risk of failure within the individual N subgroups (P=0.03). A modified TNM staging system based on LND ratio was consistently superior to the traditional system in estimating survival measures.Conclusion:This multi-institutional study validates the reliability and applicability of LND as a predictor of outcomes in OSCC. Lymph node density can potentially assist in identifying patients with poor outcomes and therefore for whom more aggressive adjuvant treatment is needed.

Cervical lymph node metastases reduce the overall survival of patients with oral squamous cell carcinoma (OSCC) and require a neck dissection. However, elective management of a clinical N0 neck remains a controversial topic, as there are no reliable factors available predicting cervical lymph node metastases. Recent studies suggest an impact of podoplanin expression on metastatic spread to the cervical lymph nodes. Our aim was to investigate the influence of podoplanin expression on prognosis and metastatic lymphatic spread. In our retrospective study, podoplanin expression was examined in a set of 80 patients with OSCC by immunohistochemistry. We analysed associations between the level of podoplanin expression and various clinicopathologic parameters. In 67 patients (84%), podoplanin was expressed on the tumour cells. Nineteen patients (24%) showed high levels of expression. The 5-year overall survival (31%) for patients with high levels of podoplanin expression was significantly lower (p < 0.001) than for patients with low and moderate expression of podoplanin (93% and 65%, respectively). There was an association between podoplanin expression and the frequency of cervical lymph node metastases. Cervical lymph node metastases were found in 79% of the patients with high podoplanin expression, while patients with weak podoplanin expression had metastases in only 22% (p < 0.001). None of the 13 patients without podoplanin expression had cervical lymph node metastases. We concluded that podoplanin is expressed frequently in OSCC and that podoplanin expression correlates with cervical lymph node metastases and clinical outcome.

Objectives: The present study assesses the accuracy of three-dimensional (3D) cone beam CT (CBCT) and intra-oral radiography (CR) in visualizing peri-implant bone compared with histology. Methods: 26 titanium dental implants were placed in dog jaws with chronic type vestibular defects. After a healing period of 2 and 8 weeks (n 5 12 dogs) the animals were sacrificed. CBCT scans and CR of the specimen were recorded. Dissected blocks were prepared, and histomorphometric analysis was performed. Both modalities were measured twice by two observers and compared with histomorphometry regarding bone levels and thickness around implants as well as length and diameter of implants. Results: Measurements of CBCT correlated well with histomorphometry of the vestibular bone level, oral bone thickness and implant length (all p-values ,0.05). Compared with histomorphometry, the mean differences between CBCT and histomorphometry were between 0.06 and 2.61 mm. Mesial bone level (MBL) and distal bone level (DBL) were underestimated by both CR and CBCT. CR and histology measurements were only significantly correlated for implant length measurements. All intraclass correlations were highly significant. Conclusions: 3D CBCT provides usable information about bone in all dimensions around implants with varying accuracy. CR and CBCT perform similar in assessing MBL and DBL, but, within its limits, the CBCT can assess oral and buccal bone. Metallic artefacts limit the visualization quality of bone around implants and further research could elucidate the value of post-processing algorithms. When information about osseous perforation of implants is needed, CBCT may still provide clinically valuable information.

BACKGROUND An association between the survival of patients with oral cavity squamous cell carcinoma (OCSCC) and advancements in diagnosis and therapy has not been established. METHODS This was a retrospective, longitudinal, international, population‐based study of 2738 patients who underwent resection of OCSCC during 2 different decades. Characteristics of patients from 7 international cancer centers who received treatment between 1990 and 2000 (group A; n = 735) were compared with patients who received treatment between 2001 and 2011 (group B; n = 2003). RESULTS Patients in group B had more advanced tumors and tended to develop distant metastases more frequently than patients in group A (P = .005). More group B patients underwent selective neck dissection and received adjuvant radiotherapy (P < .001). Outcome analysis revealed a significant improvement in 5‐year overall survival, from 59% for group A to 70% for group B (P < .001). There was also a significant improvement in disease‐specific survival associated with operations performed before and after 2000 (from 69% to 81%, respectively; P < .001). Surgery after 2000, negative margins, adjuvant treatment, and early stage disease were independent predictors of a better outcome in multivariate analysis. The decade of treatment was an independent prognostic factor for cancer‐specific mortality (hazard ratio, 0.42; 95% confidence interval, 0.3‐0.6). CONCLUSIONS The survival rate of patients with OCSCC improved significantly during the past 2 decades despite older age, more advanced disease stage, and a higher rate of distant metastases. The current results suggest that the prognosis for patients with OCSCC has improved over time, presumably because of advances in imaging and therapy. Cancer 2013;119:4242–4248. © 2013 American Cancer Society.