A prolonged period of oral surgery is a potential risk factor of postoperative mental disorders although no such report has been published to date. We retrospectively studied perioperative features in 36 patients who underwent prolonged (10 hours or more) of oral surgery. Patients were categorized as predelirium (Pre-D) when they manifested 1 or 2 symptoms and delirium (D) when they showed more than 2 symptoms, according to the modified International Classification of Diseases, 10th edition. Of the 36 patients who returned to a normal mental state without drug therapy, 13 were classified as D and 14 were Pre-D. A number of patients had moderate complications preoperatively, and massive hemorrhaging occurred during the operation in some Pre-D and D patients. Age was greater in D (62.0 ± 9.9 years) than in Pre-D (56.0 ± 13.8 years) patients. Propofol-based general anesthesia was most commonly employed. The time prior to appearance of pre-delirium was significantly shorter in D (30.0 ± 16.7 hours) than in Pre-D (55.0 ± 35.0 hours) group patients. Our results indicate that, in general, patients predisposed to postoperative mental disorders have moderate complications preoperatively, are generally older than 50-years-old, receive propofol-based general anesthesia and/or experience a massive hemorrhage during the operation. (J. Oral Sci. 46, 71-74, 2004)

View full abstract

The effect of therapeutic agents on trabecular bone loss in the mandible was investigated in ovariectomized rats. Eighty-seven Wistar SPF female rats were ovariectomized (OVX) or given a sham operation (Sham), and maintained on a diet containing 0.1 % calcium. Four weeks later, groups of OVX rats were treated with estriol (E3), calcitonin (CT), etidronate, or 2-carboxyethylgermanium sesquioxide (Ge-132). The Basal group was maintained on a diet containing 1.0 % calcium, and the OVX and sham groups on a diet containing 0.1 % calcium. The trabecular bone mineral density (BMD) and trabecular bone mineral content (BMC) in 11 mandibular slices from 0.5 mm at the mesial margin of the first molar to 0.5 mm at the distal margin of the third molar, were measured using peripheral Quantitative Computed Tomography (pQCT). The BMD in the OVX group was lower than that in the Sham group, and decreased BMC was observed only in the molar region. BMD and BMC were increased in the etidronate-treated group, but only BMC was increased in the CT group. E3 treatment increased BMD and BMC; significant increases were also observed beneath the molar. Ge-132 treatment increased both BMD and BMC, especially the latter. (J. Oral Sci. 46, 75-85, 2004)

View full abstract

The aim of this study was to evaluate the role of PCNA and AgNOR in the assessment of salivary gland tumor proliferation using a double staining technique. Ten cases of pleomorphic adenoma (PA) and seventeen cases of adenoid cystic carcinoma (ACC) were examined. Numeric and morphometric parameters of AgNOR were evaluated and compared in PCNA-positive and PCNA-negative nuclei. There were statistically significant differences in AgNOR numbers, perimeters and contour indices between PCNA-positive and -negative nuclei in the PA samples. The ACC samples demonstrated significant differences only in the AgNOR areas. Our results show that in salivary gland tumors there is not always a relationship between proliferative activity evaluated by AgNOR numeric and morphometric parameters and PCNA immunostaining. (J. Oral Sci. 46, 87-92, 2004)

View full abstract

Porphyromonas gingivalis, a Gram-negative anaerobe associated with adult periodontitis, expresses numerous potential virulence factors. dnaK, a member of the heat shock protein family, functions as a molecular chaperone and plays a role in microbial pathogenicity. However, little is known regarding its gene expression caused by oxygen stress in P. gingivalis. In the present study, a custom-made DNA microarray was designed and used to monitor dnaK gene expression in P. gingivalis caused by oxygen stress. The results demonstrated that dnaK mRNA was up-regulated in a short time, and the DNA microarray results were confirmed by real-time polymerase chain reaction analysis. These findings suggest that oxygen stress stimulates gene expression of dnaK and may have a relationship to the aerotolerance activity of this organism as well as its expression of pathogenesis. (J. Oral Sci. 46, 93-100, 2004)

View full abstract

Human immunodeficiency virus (HIV) infection remains a serious problem in northern Thailand. A high prevalence of perinatally HIV-infected children with oral candidiasis has been observed in the region. The objective of this study was to determine oral colonization of Candida spp. in children with perinatal HIV infection. Samples were collected by oral rinse or oral swab from 40 HIV-infected children and from 15 HIV-negative children as a control group. Yeasts recovered in culture were identified and quantified. The mean ages of HIV-infected children and HIV-negative children were 5.5 years (SD = 3.5) and 2.9 years (SD = 2.0) respectively. Eighteen HIV-infected children (45 %) had clinical symptoms of oral candidiasis while none of the HIV-negative children had any such symptoms. By culture technique, yeasts were isolated from 28/40 (70 %) of the HIV-infected children and 6/15 (40 %) of the HIV-negative children. C. albicans was the most common species recovered from HIV-infected and HIV-negative children. Statistically, HIV infection was significantly associated with Candida spp. detection (P-value = 0.04). In contrast, the association between HIV infection and asymptomatic oral carriage of Candida spp. was not significant (P-value = 0.74). These findings demonstrate that oral colonization of Candida spp. is prevalent in HIV-infected children and suggest that prevention and treatment of oral candidiasis is needed for these children. (J. Oral Sci. 46, 101-105, 2004)

View full abstract

The main known benefit of calcium hydroxide as an intracanal medicament lies in the bactericidal effect conferred by its pH. The objective of this work was to determine the influence of the vehicle on the pH of calcium hydroxide pastes after usage in patients and in vitro. The incisor root canals of 180 patients were instrumented and filled with calcium hydroxide pastes containing distilled water, chlorhexidine, propylene glycol, anesthetic solution, camphorated p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol. The pH of the paste in the patients' root canals was measured at 7, 14 and 21 days. Similarly, pH was measured in vitro up to 21 days. The pH of all the pastes remained constant throughout the time periods assessed. The calcium hydroxide-water combination showed significantly higher pH values than the other pastes in clinical use. Comparative analysis showed that the pH values of the anesthetic solution, camphorated p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol were significantly higher in vitro. The type of vehicle was shown to influence the final pH of the pastes. However, the alkalinity of all pastes was maintained over time under the experimental conditions. (J. Oral Sci. 46, 107-111, 2004)

View full abstract

This study evaluated the effect of oral cancer surgery on masticatory efficiency. Masticatory efficiency was measured using the ATP absorption method. Eating ability was measured using a questionnaire. Two groups were employed as controls: The “normal occlusion group” consisted of subjects who had a complete set of natural maxillary teeth opposed to mandibular teeth, and the “unilateral occlusion group” consisted of subjects who had lost their molar and premolar teeth on one side of the mandible as a result of caries or periodontal diseases. Three treatment groups, each of 6 patients, were studied: a glossectomy group, a marginal mandibulectomy group and a segmental mandibulectomy group. There were no differences in masticatory efficiency between two control groups. Masticatory efficiencies of the three oral cancer treatment groups were lower than in the unilateral occlusion group, even 12 months after surgery. Masticatory efficiency of the glossectomy group was significantly higher 12 months after surgery compared with pre-surgery. Masticatory and eating abilities of the marginal mandibulectomy group and the segmental mandibulectomy were reduced at 3 and 6 months after surgery. The masticatory efficiency 12 months after surgery was higher in the marginal mandibulectomy group than the segmental mandibulectomy group, although the difference was not statistically significant. The self assessed eating ability 12 months after surgery was significantly higher in the marginal mandibulectomy group than the segmental mandibulectomy group. These results suggest that discontinuation of the mandible may lead patients to eat only foods that do not require a substantial amount of chewing. Hence, the quality of life of patients in the marginal mandibulectomy group was considered to be better than that in the segmental mandibulectomy group. (J. Oral Sci. 46, 113-117, 2004)

View full abstract

Saliva is known to play important roles in such functions as swallowing, mastication, speech, and taste. Furthermore, salivary glands synthesize and secrete a number of growth factors involved in cell/tissue homeostasis. It has been demonstrated that IGF-1, which is structurally analogous to insulin, has been shown to be expressed in mouse submandibular glands, and that IGF-1 stimulates DNA synthesis, amino acid uptake, protein synthesis, and glucose transport in various cells. Diminished function of the salivary glands is thought to lead to increased dental caries and periodontal diseases, which are commonly associated with aging. However, very little is known regarding the effects of age on IGF-1 expression in submandibular glands. The senescence-accelerated mouse (SAM), an experimental murine model of accelerated aging, has been extensively used to examine the mechanisms responsible for aging. In the present study, IGF-1 production and mRNA levels in the submandibular glands of SAM-P1 mice were examined. IGF-1 levels were determined by radioimmunoassay and IGF-1 mRNA levels by semi-quantitative RT-PCR. We found that IGF-1 protein levels in homogenates and IGF-1 mRNA levels decreased with age in SAMP1 mice. These findings suggest that IGF-1 synthesis in submandibular glands decreases with aging, and this may result in lower levels of cellular proliferation, regeneration and wound healing in aged oral tissues. (J. Oral Sci. 46, 119-125, 2004)

View full abstract

The purpose of this survey was to investigate the relationship between demographic characteristics and willingness of patients to pay for regular dental check-ups in Japan. Questionnaires were distributed at private dental offices and collected via postage-paid return envelopes addressed to the center of the study groups. Questions focused on demographics and willingness to pay for regular check-ups. Five thousand one hundred thirty-two questionnaires were collected (response rate 56.8 %). The 3 groups most likely to have regular dental check-ups were found to be the under 20s, 50 to 59 year olds and civil servants. Of these groups, civil servants were found to be the most likely of all to have regular check-ups. More females than males were represented in the sample. More than 60 % of the patients responded that they would be willing to pay for regular check-ups if the cost were less than 2,000 yen (about $ 20). However, no statistically significant differences were observed in relation to household income. The results suggested that participation in regular dental check-ups might be related to gender and age, but not to household income. (J. Oral Sci. 46, 127-133, 2004)

View full abstract