Treatment of self-inflicted oral trauma in a comatose patient: a case report.

Trauma to oral soft tissues in comatose patients may be more widespread than reported, as no extensive study of this problem has been conducted. Various appliances for the prevention of self-inflicted injuries to oral tissues particularly in children and the physically and mentally challenged have been documented, but there is little information on their use in adult comatose patients. Because comatose patients lack cerebral control of the masticatory cycle, they can easily injure themselves. Although it is not uncommon for patients with a decreased level of consciousness and in need of intensive care to be restrained to prevent injury due to involuntary movement of the limbs, head and neck restraint is often difficult and may be dangerous to the patient. This case report presents a simple solution to the problem of self-inflicted trauma to oral tissues.

Establishment of immortalized clonal cells derived from periodontal ligament cells by induction of the hTERT gene.

Since the periodontal ligament (PDL) contains a heterogeneous cell population, it is challenging to identify all cell types within the tissue and to determine whether they function alone to produce tissue components or interact with other cell types. Further, it is difficult to isolate and expand single cell clones from PDL cells, as normal cells have a limited life span and are phenotypically unstable. In the present study, we inserted the human telomerase reverse transcriptase (hTERT) gene, which encodes the catalytic subunit of the telomerase holoenzyme, into normal human periodontal ligament (HPL) cells and successfully obtained single cell clones. Expression of the inserted gene and telomerase activity in each of the clones was confirmed. Unlike the original HPL cells, at the end of the study (day 120), clone populations continued to actively double without phenotypic alteration. Osteogenic characteristics were present in some but not all clones. In conclusion, immortalization of HPL cells was successfully accomplished by transduction with the hTERT gene. This is the first report of immortalization of different cell types derived from PDL.

The subgingival microflora in phenytoin-induced gingival hyperplasia.

OBJECTIVES: Microbial flora and gingival conditions were compared between a group of patients with phenytoin-induced gingival hyperplasia as a test group, a control group of patients who were administered phenytoin without gingival hyperplasia and a blank group who took no phenytoin and no gingival hyperplasia in mentally retarded patients. MATERIALS AND METHODS: Subgingival plaque samples were collected from a PHT-induced overgrown gingival pocket and microbiological experiments were performed by culture and PCR methods. RESULTS: The predominant genera in total cultivable bacteria from subgingival plaque samples were streptococcus and actinomyces with recovery ranges of 37.6-42.1% and 23.4-25.5% of total bacteria, respectively, in all groups. The test group showed a significantly higher level of obligate Gram-negative rods than the control and blank groups. Black-pigmented obligate anaerobic Gram-negative rods were detected in 10.3% of total cultivable bacteria in the test group. The black-pigmented rods were predominantly Prevotella intermedia in the test group and Prevotella nigrescens in the control and blank groups. Porphyromonas gingivalis and Porphyromonas endodontalis were also detected in the test group with small values. CONCLUSIONS: These results suggested that black-pigmented rods, particularly P. intermedia, could be habitable in the environment of gingival hyperplasia.

Enhancement of lipopolysaccharide-stimulated cyclooxygenase-2 mRNA expression and prostaglandin E2 production in gingival fibroblasts from individuals with Down syndrome.

It is well known that Down syndrome (DS) is a premature ageing syndrome. Periodontal disease in individuals with DS develops rapidly and extensively in a relatively younger age bracket compared with that in healthy controls. The mechanisms involved in the periodontal inflammatory processes in DS patients are not fully understood. In the present study, the non-inflamed gingival fibroblasts isolated from seven patients with DS (DGF) and seven healthy controls (NDGF) were stimulated with lipopolysaccharide (LPS) derived from Actinobacillus actinomycetemcomitans (A. a.). We measured the level of prostaglandin E2 (PGE2) production by DGF and NDGF by radioimmunoassay, and also measured the mRNA expression of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) by using the real-time PCR method. We found the higher levels of LPS-stimulated COX-2 mRNA expression and PGE2 production in DGF when compared with those in NDGF. This study may indicate that overexpression of LPS-stimulated COX-2 induced a greater ability of DGF to produce PGE2, and that these phenomena may be responsible for the severer periodontal disease in DS patients.