Bite Force and Masticatory Performance Using Implant-supported Overdentures After Treatment of Mandibular Cancer.

AIM: To evaluate overdentures with regard to artificial restoration of oral function following mandibular cancer. MATERIALS AND METHODS: We examined 32 patients who had undergone mandibular bone resection as treatment for malignancy and were using implant-supported overdentures. The patients were aged 55-87 years (mean=68.6) with a male to female ratio of 23:9. Marginal resection was performed in 29 patients and segmentectomy in 3. RESULTS: Before and after using the attachment for overdenture, oral function differed significantly. After the setting of implant-retained overdentures, maximum bite force increased on average by 362% (average, from 16.2 N to 58.8 N; p<0.01). Xylitol gum examination showed a 363% increase in masticatory performance (average, 3.1 to 8.0 points; p<0.01). CONCLUSION: Implant-retained overdenture resulted in improved oral function, that was lost after treatment for mandibular cancer.

Custom-made titanium devices as membranes for bone augmentation in implant treatment: Clinical application and the comparison with conventional titanium mesh.

OBJECTIVE: Development of new custom-made devices to reconstruct alveolar bone for implantation, and comparison with conventional methods were the goals of this study. MATERIALS AND METHODS: Using a computer-aided design technique, three-dimensional images were constructed. From these data, custom-made devices were produced by a selective laser melting method with pure titanium. Clinical trials also have been conducted with 26 participants who needed bone reconstruction before implantation; they were divided into 2 groups with 13 patients each. The first group uses custom-made devices; the other uses commercial titanium meshes that need to bend during operation. Some clinical aspects are evaluated after the trial. RESULTS: The custom-made devices can be produced closely by following the data precisely. Devices are fit for bone defect site. Moreover, the operation time of the custom-made group (75.4 ± 11.6 min) was significantly shorter than that of the conventional group (111.9 ± 17.8 min) (p < 0.01). Mucosal rupture occurs, without significant difference (p = 0.27), in a patient in the custom-made without severe infection (7.7%), and 3 in conventional (23.1%), respectively. The retaining screw is significantly fewer in the custom-made group than commercial mesh group (p < 0.01). CONCLUSION: These results indicate that our novel protocol could be simple and safe for providing powerful support for guided bone regeneration.

p38 phosphorylation in medullary microglia mediates ectopic orofacial inflammatory pain in rats.

BACKGROUND: Orofacial inflammatory pain is likely to accompany referred pain in uninflamed orofacial structures. The ectopic pain precludes precise diagnosis and makes treatment problematic, because the underlying mechanism is not well understood. Using the established ectopic orofacial pain model induced by complete Freund's adjuvant (CFA) injection into trapezius muscle, we analyzed the possible role of p38 phosphorylation in activated microglia in ectopic orofacial pain. RESULTS: Mechanical allodynia in the lateral facial skin was induced following trapezius muscle inflammation, which accompanied microglial activation with p38 phosphorylation and hyperexcitability of wide dynamic range (WDR) neurons in the trigeminal spinal subnucleus caudalis (Vc). Intra-cisterna successive administration of a p38 mitogen-activated protein kinase selective inhibitor, SB203580, suppressed microglial activation and its phosphorylation of p38. Moreover, SB203580 administration completely suppressed mechanical allodynia in the lateral facial skin and enhanced WDR neuronal excitability in Vc. Microglial interleukin-1ß over-expression in Vc was induced by trapezius muscle inflammation, which was significantly suppressed by SB203580 administration. CONCLUSIONS: These findings indicate that microglia, activated via p38 phosphorylation, play a pivotal role in WDR neuronal hyperexcitability, which accounts for the mechanical hypersensitivity in the lateral facial skin associated with trapezius muscle inflammation.