This study aimed to construct throe-dimensional finite element model of the mandibular complete overdenturo and to analyze the influence rules for stress distribution under different mandibular shapes. The layer cutting method was employed as a basic tool to deal with different plaster models to gain two-dimensional point data. These data were introduced to the commercial software ANSYS to construct throe-dimensional finite element model of the mandibular complete overdenturo, including nine kinds of typical shapes, such as sharpness, roundness and squareness, and etc. Static loads were imposed on denture so as to accomplish biomechanicel analysis and to study the influence rules of stress distribution for mandibular complete overdenturo under different mandibular shapes. Results revealed that the sequence of stress from high to low was squareness, roundness, sharpness and the other extrapolated, basic and inside. The throe-dimensional finite element model has high simulation accuracy and the results provide an experimental foundation and guidance for clinical work.

Objective To evaluate the efficacy of pregabalin on painful radiation-induced brachial plexus injury.Methods A total of forty-five patients with painful radiation-induced brachial plexus injury were assigned to treatment group with pregabalin 150-600 mg/d combined with conventional therapy, and to control group with conventional treatment for 12 weeks.The visual analogue scale (VAS) and neuropathic pain symptom inventory (NPSI) were evaluated.The response rate (proportion of subjects with at least a 30％ to 50％ reduction in visual analogue scale) was evaluated as the primary endpoint.Results The response rate of the pregabalin group(36.4％) was significantly higher than that of the control group (9.1％) (x2 =4.98, P ＜ 0.05).Although hospital anxiety and depression level, clinical global impression of change, and clinical global impression of change (CGIC) did not differ significantly between pregabalin group and control group (P ＞ 0.05), improvements in neuropathic pain symptom inventory (NPSI), patient global impression of change (PGIC) and the sleep interference score(t =-6.62,-5.65,-6.16, P ＜ 0.05)suggested some utility in the management of radiation-induced brachial plexus.Conclusions Pregabalin treatment combined with conventional treatment exerts efficacy on patients with painful radiation-induced brachial plexus and patients are well tolerated.

Objective To investigate the characteristics and measurements of radiation-induced cervical cord injury (RICCI) in patients with nasopharyngeal carcinoma after radiotherapy,and explore its risk factors.Methods A retrospective study was performed on the clinical data of 30 RICCI patients with nasopharyngeal carcinoma after radiotherapy and 31 patients without RICCI (control group),admitted to our hospital from January 2000 to October 2013.Clinical symptoms and signs,imaging data of RICCI patients with nasopharyngeal carcinoma after radiotherapy were analyzed,and univariate analysis and Logistic regression analysis were used to explore the risk factors of RICCI in patients with nasopharyngeal carcinoma after radiotherapy.The effect of new type neuropathic pain inhibitor pregabalin on Lhermitte's sign (LS) was observed.Results LS was a common manifestation of RICCI; LS occurred after the initial radiotherapy in 19 patients,and 4 developed after re-irradiation for recurrences.Radiological imaging showed cervical spinal cord atrophy in 4 patients and enlargement in 17.The incidence of MRI checked exception was higher when irradiation dose of cervical node was over 64 Gy (P＜0.05).Significant differences of irradiation doses of cervical lymph node,methods of radiotherapy and re-irradiation were noted between the RICCI group and non-RICCI group (P＜0.05); further Logistic regression demonstrated that irradiation dose of cervical lymph node was an independent risk factor for RICCI (OR=1.877,95％CI:1.282-2.748,P=0.001).Remission rate of LS in patients accepted pregabalin (73.3％) was significantly higher than those without pregabalin (25.0％,P=0.039).Conclusions RICCI may occur in nasopharyngeal carcinoma patients following radiotherapy; irradiation dose of cervical lymph node is an independent risk factor for RICCI.LS is a common manifestation of RICCI,and pregabalin could effectively relief LS.