Shigeo Yamachika

Development and Growth of Adenomatoid Odontogenic Tumor Related to Formation and Eruption of Teeth

The number of published cases of adenomatoid odontogenic tumor (AOT) has steadily increased, and about half were reported in Asian populations. Although the clinicopathologic profile of AOT has been extensively reported, factual knowledge of its pathogenesis is rudimentary at best, and there is controversy as to precisely which odontogenic epithelium it arises from. AOT is a successional tooth-associated lesion which develops during the mixed dentition. The permanent successor differs from its deciduous predecessor in that it has an eruptive pathway from the dental follicle to the gingiva, the gubernaculum dentis. With this background in mind, the present review focuses mainly on the early development of AOT. We successfully demonstrated a close spatial relationship between AOT and the gubernaculum dentis in a typical case. From further observations of the same AOT in which an enclosed permanent canine showed enamel hypoplasia, it is possible to pinpoint areas around the crown of a developing successional tooth in continuity with the gubernaculum dentis as starting points. In addition, we discuss the unifying histogenetic concept of three clinical variants, namely, pericoronal (follicular), extracoronal (extrafollicular), (see Article note) and peripheral.

The application of a night guard for sleep-related xerostomia.

OBJECTIVE The usefulness of a night guard for nocturnal xerostomia was investigated. STUDY DESIGN A controlled clinical trial was conducted, and the primary outcome measure was the satisfaction with the night guard in subjective improvement of the sensation of nocturnal dryness. The night guard device was fabricated with a 1.5-mm-thick ethylene vinyl acetate sheet, which covered the dental arch and the hard palate, and did not possess a reservoir for retaining a saliva substitute. RESULTS Following completion of 2-week treatment, substantial improvement was reported by the treatment group compared with the control group (P = .025). The posttreatment VAS value was significantly decreased compare with that of pretreatment period in sensation of oral dryness (P = .0295), thirstiness (P = .0012), and burning sensation of the tongue (P = .0371) in the treatment group CONCLUSION The application of a night guard is suggested to be a useful and simple method for the management of nocturnal xerostomia.

Inhibition of pilocarpine-induced saliva secretion by adrenergic agonists in ICR mice

The aim of the present study was to clarify the effects of the adrenoceptor agonist isoproterenol (IPR) on saliva secretion stimulated by the muscarinic receptor agonist pilocarpine (PILO) in mice. Mice were injected with either 0.5 mg/kg, i.p. PILO alone or simultaneously with 2 mg/kg, i.p., IPR to evaluate the inhibitory effects of adrenoceptor agonists on saliva secretion. The mechanisms underlying changes in saliva flow rate were evaluated by histological examination of aquaporin 5 (AQP5) and saliva flow rate using the adenylate cyclase (AC) inhibitor SQ22536 (0.25 mg per mouse, s.c.), which was administered 30 min prior to PILO and/or IPR. Saliva volume decreased significantly in the mice treated simultaneously with PILO + IPR compared with that in mice treated with PILO alone. Changes in the intracellular localization of AQP5 were seen in PILO + IPR‐treated mice, and those changes were reversed by SQ22536 pretreatment. In addition, the decreased salivary flow rate in the PILO + IPR‐treated mice was partially restored by SQ22536 pretreatment. There were no significant changes in intracellular calcium or ATP levels among the groups. The results of the present study suggest the existence of an inhibitory effect of the sympathetic nervous system on parasympathetic‐stimulated salivary secretion from the salivary gland.

Factors associated with the presence of atrophic tongue in patients with dry mouth

PURPOSE This study aimed to identify factors associated with atrophic tongue in patients with dry mouth. METHODS Discriminant analysis was performed in 1265 patients with dry mouth to identify factors that might influence the risk of developing atrophic tongue. The dependent variable was the presence of atrophic tongue, while patient age, resting saliva flow rate, stimulated saliva flow rate and Candida colony-forming units (CFU) were used as the independent variables. RESULTS The standardised linear discriminant coefficients showed that Candida CFU, stimulated saliva flow rate and age were significantly associated with the presence of atrophic tongue. The following linear discriminant function was obtained: z = 0.024 × age - 0.63 × (resting saliva flow rate) - 0.81 × (stimulated saliva flow rate) + 0.002 × Candida CFU - 0.611. CONCLUSION High Candida CFU, low stimulated saliva flow rate and advanced age were identified as closely associated factors for the risk of development of atrophic tongue.

Efficacy of Fungiflora Y staining for the diagnosis of oral erythematous candidiasis.

OBJECTIVE The purpose of this study was to investigate the efficacy of Fungiflora Y staining (fluorescent stain) for the diagnosis of erythematous candidiasis. SUBJECTS AND METHODS This study enrolled 48 patients who were diagnosed with erythematous candidiasis and who underwent fungal culture and microscopic examination of a smear specimen stained with CytoQuick (modification of the Giemsa stain) and Fungiflora Y. Fungiflora Y staining was observed using a portable fluorescent microscope (CyScope(®)). The sensitivity, specificity and positive and negative predictive values were calculated using fungal culture as the gold standard test. Accuracy was calculated, and the difference between the CytoQuick and Fungiflora Y groups was examined using contingency tables and the chi-square test. RESULTS The sensitivity and specificity of the CytoQuick stain was 0.51 and 0.91, respectively; the positive predictive value was 0.95, and the negative predictive value was 0.36. The sensitivity and specificity of the Fungiflora Y stain was 0.84 and 1.0, respectively; the positive predictive value was 1.00, and the negative predictive value was 0.65. The accuracy of Fungiflora Y (0.88) was superior to that of CytoQuick (0.60) (p = 0.0052). CONCLUSIONS Microscopic examinations of smear specimens using a combination of Fungiflora Y staining and the CyScope(®) portable fluorescent microscope was found to be useful for the diagnosis of oral erythematous candidiasis.

Efficient diagnosis of Sjögren's syndrome to reduce the burden on patients

Abstract Objective. The purpose of this study was to investigate the procedures for efficiently diagnosing Sjögrens syndrome to reduce patient burden. Methods. This study analyzed data from 254 Japanese patients diagnosed with Sjögrens syndrome out of 4967 who visited our clinic complaining of xerostomia. Results. Of the 254 Sjögrens syndrome patients, 140 fulfilled the criteria proposed by the Committee on Sjögrens Syndrome of the Ministry of Health and Welfare of Japan, 228 fulfilled the criteria proposed by the American-European Consensus Group, and 69 fulfilled the criteria proposed by the American College of Rheumatology. Numbers of definitive cases varied with each set of criteria. Logistic regression analysis was used to analyze useful examination items for definitive diagnosis of Sjögrens syndrome, demonstrating that anti-Ro/SSA (odds ratio (OR), 7.165), lip biopsy (OR, 4.273), sialography (OR, 2.402), and ANA (OR, 0.678) correlated significantly with definitive diagnosis of Sjögrens syndrome. Conclusions. These results suggest that the following diagnostic procedure for Sjögrens syndrome would reduce burden on patients. When clinicians choose examination items for diagnosing Sjögrens syndrome, they should first select which criteria to use. Then, to minimize the number of examination items, examinations should be performed in order of anti-SSA antibody, lip biopsy, and parotid gland sialography.