Materials and Methods: A 3D prototype of a mandibular premolar was generated by Digital Imaging and Communications in Medicine (DICOM) images obtained from the cone beam computed tomography and imported to 3D modeling software tool, SpaceClaim. The four distinct load magnitudes of 100, 150, 200, and 250N were applied as a pressure load perpendicular to the lingual plane of the lingual cusp of the occlusal surface (normal load) and at 45° to same (oblique load). The stress distribution patterns and the maximum von Mises stresses were analyzed and compared.
Results: The occlusal stresses were distributed from the force loading point in an approximate actinomorphic pattern, and when the force load was close to the margin, the stress was much greater.
Conclusion: Ovoid cavity showed lesser stress concentration and deformation for each of the tested restorative material.
AIM: To evaluate resting tongue position in recently extracted and long term completely edentulous patients, and to evaluate the efficacy of achieving retracted tongue position by simple modification in complete denture along with certain tongue exercises.
MATERIALS AND METHODS: A total of 62 study subjects were classified into two groups based on duration of edentulousness. Group A: Recently extracted completely edentulous subjects (<1 year), Group B: Long term completely edentulous subjects (>1-10 year). The patients with retracted tongue position were subjected to a simple modification in complete denture along with inclusion of certain tongue exercises. After eight months patients were recalled and evaluated. The data was analysed using SPSS statistical tests like mean, standard deviation, proportion, Chi square test and McNemar Test.
RESULTS: Among the study subjects, 54.9% had retracted tongue position. Group B showed high proportion of retracted tongue position (68.8%) as compared to Group A. After the intervention, 42.8% study subjects gained normal resting tongue position.
CONCLUSION: Long term completely edentulous subjects presented retracted tongue position in higher percentage when compared to the recently extracted group. The interventional method employed for the subjects with retracted tongue position, played a significant role to assume normal resting tongue position and showed improvement in denture stability and retention.
OBJECTIVE: To explore the feasibility of using cyclin D1 as a prognostic marker in tongue and cheek SCC by the fluorescent-in-situ hybridization (FISH) method.
METHODS: Fifty paraffin-embedded samples (25 each of cheek and tongue SCCs) were obtained from the archives of the Oral Pathology Diagnostic Laboratory. Sociodemographic data, histopathologic diagnoses, lymph node status and survival data were obtained from the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS)coordinated by the Oral Cancer Research and Coordinating Centre (OCRCC), University of Malaya. The FISH technique was used to detect the amplification of cyclin D1 using the Vysis protocol. Statistical correlations of cyclin D1 with site and lymph node status were analyzed using the Fisher exact test. Kaplan-Meier and Log Rank (Mantel-Cox) test were used to analyze cyclin D1 amplification and median survival time.
RESULTS: Positive amplification of cyclin D1 was detected in 72% (36) of OSCCs. Detection of positive amplification for cyclin D1 was observed in 88% (22) and 56% (14) of the tongue and cheek tumors, respectively, where the difference was statistically significant (P=0.012). Lymph node metastasis of cheek SCCs showed a trend towards a significant association (P= 0.098) with cyclin D1 amplification whereas the lymph node metastasis of tongue SCC was clearly not significant (P=0.593).There was a statistically significant correlation between cyclin D1 positivity and survival rate (P=0.009) for overall SCC cases and (P<0.001) for cheek SCC cases.
CONCLUSION: The present study found that cyclin D1 amplification may differ in different subsites of OSCC (tongue vs cheek) and its positive amplification implies an overall poor survival in OSCCs, particularly those arising in cheeks.