Salivary Cotinine Concentrations and Prevalence of Periodontal Disease in Young Japanese Women: The Kyushu Okinawa Maternal and Child Health Study

Background: The authors investigated the relationship between objectively assessed tobacco smoke exposure and periodontal disease. Methods: This cross‐sectional study included 1,103 women with a mean age of 31.5 years. Information on potential confounding factors was obtained through a self‐administered questionnaire. Periodontal disease was defined as positive if a woman had at least one tooth with a probing depth of ≥3.5 mm. Exposure to tobacco smoke was determined based on salivary cotinine concentration. Adjustment was made for age, region of residence, household income, education, toothbrushing frequency, and use of an interdental brush. Results: The prevalence of periodontal disease was 11.3%. Salivary cotinine concentration was independently positively associated with the prevalence of periodontal disease: the adjusted odds ratio for every 1‐unit (ng/mL) increase in salivary cotinine was 1.004 (95% confidence interval: 1.000 to 1.007). Conclusion: Salivary cotinine concentrations were positively associated with the prevalence of periodontal disease among young women.     

Influence of preoperative dental procedures on the prognosis of patients with squamous cell carcinoma of the gingiva

Our aim was to investigate the prognosis of patients with squamous cell carcinoma (SCC) of the gingiva who had preoperative dental operations. We studied 102 patients who were being operated on for SCC of the gingiva with special reference to the effects of preoperative dental operations on the prognosis. Twenty-six patients had dental procedures such as tooth extraction, or incision, or curettage before they visited our hospital, while the remaining 76 had no such interventions. The percentage of patients with advanced T stage disease (T3 or T4) was higher among those who had interventions (17/26, 65%) than among those who had not (35/76, 46%). The difference was not significant. Histopathologically invaded nodes were detected in half the patients in the intervention group (13/26), while they were found in only 18/76 (24%) of those in the no intervention group (p < 0.02). The incidence of nodal metastases with extranodal spread was significantly higher in the intervention group than in the no intervention group (p < 0.05), and those in the intervention group were more likely to develop distant metastases than those in the other group (p < 0.001). The 5-year survival in the two groups was 65% and 92%, respectively (p < 0.01). Preoperative dental operations such as tooth extraction, incision, or curettage possibly lead to regional and distant metastases and therefore a poor prognosis in patients with SCC of the gingiva.     

A Case of Carcinoma Ex Pleomorphic Adenoma in the Buccal Mucosa: Review of the Literature

We present a case of carcinoma ex pleomorphic adenoma on the right buccal mucosa in a 52-year-old Japanese woman. Based on the histopathology, the excised tumor was the non-invasive type, but the majority of the tumor consisted of poorly-differentiated adenocarcinoma cells. We performed proton radiation after the surgery. The patient was well, without evidence of disease, 48 months after surgery. Carcinoma ex pleomorphic adenoma in the buccal mucosa has been reported in only four cases during the past twenty years. Therefore, our case was comparatively rare.     

Micro-CT observation of test food materials for videofluoroscopic swallowing studies

Objectives

We examined the usefulness of micro-computed tomography (micro-CT) to measure the distributions of contrast media in materials that simulated the properties of test foods for videofluoroscopic (VF) swallowing studies (VFSS).

Methods

Food samples that simulated rice, rice gruel, custard pudding, udon noodles, and liquids were prepared with barium sulfate and iodine contrast media. These samples and simulated foods containing no contrast medium were subjected to micro-CT. The micro-CT scanning was performed using a ScanXmate-RB090SS. Each sample was used to fill a cylindrical container with an inner diameter of 8 mm and a height of 35 mm or a 1-mL plastic syringe, and images were acquired at a voltage of 90 kV, current of 45 μA, and magnification power of 2.5. From the acquired data, 610 × 610-pixel 8-bit image slices were prepared and observed using OsiriX software. The image densities (pixel values) were measured for regions of interest. The obtained pixel values were then normalized on the basis of the density of the barium sulfate contrast medium and water.

Results

The infiltration or distributions of the contrast media in the VF test materials were successfully observed, and their values ranged widely compared with the barium sulfate contrast medium.

Conclusions

Micro-CT imaging was capable of numerically presenting or visualizing the density and distribution of VF test materials, thereby showing its usefulness as an objective evaluation method. Using this technique, it may be possible to adjust test foods to the optimum contrast properties for clinical VF examinations.     

The observational study of delayed wound healing after tooth extraction in patients receiving oral bisphosphonate therapy

IntroductionIn this study, we investigated whether such a discontinuation of oral bisphosphonate (BP) for 3 months might influence the incidence of BP-related osteonecrosis of the jaw (BRONJ) and wound healing after tooth extraction in patients receiving oral BP therapy.Material and methodsThere were a total of 434 teeth in 201 patients (18 males and 183 females). The patients were divided into two groups depending on whether or not they underwent a 3-month discontinuation of BP therapy (BP? and BP+) before tooth extraction. In this observational study investigated delayed wound healing after tooth extraction in patients receiving oral BP therapy.ResultsIn all cases of the BP? group, there were no BRONJ although there was delayed wound healing in two cases. However, in one case of the BP+ group, oral BP was continued because it was deemed high risk to discontinue treatment by the patient's physician. In this case, an intraoral fistula was still present with bone exposure at 120 weeks after extraction (BRONJ stage 1).ConclusionThis study supports the idea of a drug holiday and encourages further clinical research on this topic of tooth extraction in patients receiving oral BP therapy.     

Electric current induced in teeth by electromagnetic fields from electric toothbrushes and curing lights

PurposeThe purpose of this study was to examine the electric current induced in teeth and tooth-bonded brackets by electromagnetic fields from electric toothbrushes and the curing lights used for photo-activating light-cured resins.Materials and methodsCuring lights-generated low-frequency magnetic fields (1–2000 Hz) were measured with a spectrum analyzer. Temperature changes induced in the enamel and pulpal dentin surface of extracted upper premolar teeth (with or without a stainless steel or zirconia bracket) by electric toothbrushes and curing lights were estimated using an infrared thermometer. Electric current induced in these extracted teeth by electric appliances was estimated using a digital multimeter.ResultsCuring lights generated low-frequency magnetic fields. Irradiation of the tooth surface by curing lights elevated the temperature of the enamel and pulpal dentin surfaces, but there were no differences between curing lights. About electric current induced in extracted teeth (with or without a bracket) by electric toothbrushes and curing lights, the highest current was induced in teeth to which a zirconia bracket was bonded, whereas the lowest current was in unmodified teeth. Intermediate currents were generated in teeth bonded to stainless steel brackets.ConclusionThe low-frequency magnetic fields induced by electric toothbrushes and light curing units induce electric current in tooth tissue, irrespective of whether these teeth are bonded to stainless steel or zirconia brackets.     

Factors affecting the bond strength of denture base and reline acrylic resins to base metal materials

Objective

The shear bond strengths of two hard chairside reline resin materials and an auto-polymerizing denture base resin material to cast Ti and a Co-Cr alloy treated using four conditioning methods were investigated.

Material and Methods

Disk specimens (diameter 10 mm and thickness 2.5 mm) were cast from pure Ti and Co-Cr alloy. The specimens were wet-ground to a final surface finish of 600 grit, air-dried, and treated with the following bonding systems: 1) air-abraded with 50-70-µm grain alumina (CON); 2) 1) + conditioned with a primer, including an acidic phosphonoacetate monomer (MHPA); 3) 1) + conditioned with a primer including a diphosphate monomer (MDP); 4) treated with a tribochemical system. Three resin materials were applied to each metal specimen. Shear bond strengths were determined before and after 10,000 thermocycles.

Results

The strengths decreased after thermocycling for all combinations. Among the resin materials assessed, the denture base material showed significantly (p<0.05) greater shear bond strengths than the two reline materials, except for the CON condition. After 10,000 thermocycles, the bond strengths of two reline materials decreased to less than 10 MPa for both metals. The bond strengths of the denture base material with MDP were sufficient: 34.56 MPa for cast Ti and 38.30 for Co-Cr alloy.

Conclusion

Bonding of reline resin materials to metals assessed was clinically insufficient, regardless of metal type, surface treatment, and resin composition. For the relining of metal denture frameworks, a denture base material should be used.     

Small Intestinal Strangulation Due to a Rare Type of Primary Internal Hernia

Internal hernias in which the gate is located in the paracolic gutter are rare. A 75-year-old man was admitted to our hospital with severe epigastric pain without past history of laparotomy and/or trauma. He was diagnosed with strangulation of the ileum by the findings of computed tomography, and the operation was performed. During laparotomy, the small intestine was found to be strangulated and to enter the retroperitoneum from the right paracolic gutter near the hepatic flexure. The patient was diagnosed with an internal hernia, which differed from a pericecal hernia in that the hernia gate was located along the paracolic gutter near the hepatic flexure far from the cecum. Hence, it was considered to be a rare type of internal hernia. We report the clinical presentation and imaging findings of this rare internal hernia.