Aberrant expression of DUSP4 is a specific phenomenon in betel quid-related oral cancer.

Oral cancer due to betel quid chewing habit is very common in South Asian countries. We attempted to detect the presence of a novel gene in epithelial cells stimulated with arecoline, a main component of betel quid. Human gingival epithelial progenitors were cultured and treated with a 3-day alternating regimen with/without 50 µg/ml arecoline for 1 month. DNA microarray and methylation arrays were analyzed to identify the candidate genes. Immunohistochemical staining was performed in the tissue samples. Genome-wide analyses, quantitative reverse transcription PCR and quantitative methylation-specific PCR revealed DUSP4 as the most significant and promising gene. The methylation levels of DUSP4 were significantly higher in the betel quid-related oral squamous cell carcinoma (OSCC) than those in the non-related OSCC and controls (Mann-Whitney U test, p < 0.05). The number of DUSP4 immunopositive cells in betel quid-related OSCC was significantly higher than those from the non-chewing patients and the controls (p < 0.05). Hypermethylation of DUSP4 may be considered as a specific event in betel quid-related oral cancer.

Scalp-Split Technique: A concept of bone splitting and expansion for thin alveolar ridges to place dental implants.

BACKGROUND: Bone expansion is where the existing bone at the implant site is split and separated to create a gap to widen it. This article introduces a novel concept of bone expansion for the ultra-thin alveolar ridges to place dental implants with zero wastage of existing natural bone in long-term edentulous arches. Instead of using twist drills and piezo surgery kits, the bone is split with a surgical scalpel blade to prevent natural bone wastage. METHODS: The split will help to expand the bone horizontally by using expanders to accommodate the smaller diameter implants. This technique was applied to 12 individuals to rehabilitate their atrophic edentulous mandibles to facilitate the implant-supported overdentures, and it revealed that all the cases achieved successful osseointegration after placing implants following this method. CONCLUSIONS: The "Scalp-Spilt Technique" is a promising technique for providing implant- retained or implant-supported prostheses over ultra-thin edentulous alveolar ridges.

Upregulation of human beta-defensin 2 peptide expression in oral lichen planus, leukoplakia and candidiasis. an immunohistochemical study.

Human beta defensin 2 (hBD-2) is a major antimicrobial peptide that is produced by many types of epithelial cells, and is transcriptionally inducible by various proinflammatory agents, such as cytokines and bacteria. Although in vitro studies of the hBDs in oral epithelial cells have been well documented, only little is known about the in vivo pathological state of oral epithelium. We investigated the localization of hBD-2 peptide in tissue sections of oral lichen planus, leukoplakia, candidal leukoplakia and radicular cysts using immunohistochemistry. HBD-2 was stained in both the hyperkeratinized and the granular layers in cases of lichen planus with hyperkeratosis and leukoplakia. Expression in spinous and suprabasal layers was often strong in lichen planus. There were no significant differences in the number of S-100 positive dendritic cells between the widely stained areas and those with limited staining areas in lichen planus. In cases of candidal leukoplakia, the hyphae of candida were mainly detected on the surface of keratinization, which showed only negative or faint staining for hBD-2. These results suggest that hBD-2 is vigorously induced by lichen planus-related inflammation and that it plays an important role in protection from Candida albicans infection; however, it is not a strong chemotactic attractant for Langerhans cells in pathological conditions of oral epithelium.