Bacteria in the tooth root canal may cause apical periodontitis. This study examined the bacterial species present in the apical root canal of teeth with apical periodontitis. Antibiotic sensitivity tests were performed to evaluate whether these identified bacterial species were susceptible to specific kinds of antibiotics. Selective media plating and biochemical tests were used first to detect the bacterial species in samples taken from the apical portion of root canals of 62 teeth with apical periodontitis. The isolated bacterial species were further confirmed by matrix-assisted laser desorption ionization-time of flight mass spectrometry. We found concomitant presence of two (32 teeth) or three species (18 teeth) of bacteria in 50 (80.6%) out of 62 tested teeth. However, only 34 bacterial species were identified. Of a total of 118 bacterial isolates (83 anaerobes and 35 aerobes), Prophyromonas endodontalis was detected in 10; Bacteroides, Dialister invisus or Fusobacterium nucleatum in 9; Treponema denticola or Enterococcus faecalis in 8; Peptostreptococcus or Olsenella uli in 6; and Veillonella in 5 teeth. The other 25 bacterial species were detected in fewer than five teeth. Approximately 80-95% of bacterial isolates of anaerobes were sensitive to ampicillin/sulbactam (Unasyn), amoxicillin/clavulanate (Augmentin), cefoxitin, and clindamycin. For E. faecalis, 85-90% of bacterial isolates were sensitive to gentamicin and linezolid. Root canal infections are usually caused by a mixture of two or three species of bacteria. Specific kinds of antibiotic can be selected to control these bacterial infections after antibiotic sensitivity testing.

Reprogramming of cellular energy metabolism, such as lipid metabolism, is a hallmark of squamous cell carcinoma of the head and neck (SCCHN). However, whether protein expression related to fatty acid oxidation (FAO) affects survival in SCCHN remains unclear. We aimed to investigate FAO-related enzyme expression and determine its correlation with clinicopathological variables in SCCHN patients. Immunohistochemical analysis (IHC) of FAO-related protein expression, including carnitine palmitoyltransferase 1 (CPT1), the acyl-CoA dehydrogenase family, and fatty acid synthase (FAS), was performed using tissue microarrays from 102 resected SCCHN tumors. Expressions were categorized according to IHC scores, and the statistical association with clinicopathological factors was determined. Moderate-to-high expression of long-chain acyl-CoA dehydrogenase (LCAD) had a protective role against cancer-related death (adjusted hazard ratio (HR), 0.2; 95% confidence interval (CI), 0.05–0.87) after covariate adjustment. Age and clinical stage remained independent predictors of survival (adjusted HR, 1.75; 95% CI, 1.22–2.49 for age; adjusted HR, 14.33; 95% CI, 1.89–108.60 for stage III/IV disease). Overexpression of medium-chain acyl-CoA dehydrogenase and FAS correlated with advanced tumor stage (T3/T4); however, none of these factors were independent predictors of survival. Several FAO-related enzymes were upregulated and LCAD overexpression had a protective effect on overall survival in advanced SCCHN patients. FAO-related-enzyme expression might have a prognostic impact on survival outcomes in SCCHN.

Oral cancer is a major cause of cancer morbidity and mortality worldwide, especially in Taiwan. This study investigated the morbidity and mortality of oral cancer in Taiwan from 2000 to 2021. The population data and the records of cancer registry were obtained from the websites of the Ministry of the Interior and the Ministry of Health and Welfare, respectively. The numbers of oral cancer cases and deaths were analyzed from 2000 to 2021. The numbers of oral cancer cases and deaths increased from 3378 to 1494 in 2000–8277 in 2020 and 3395 in 2021, respectively. The total increase of oral cancer cases was 4899 with a total increase rate of 145.03%, while the total increase of oral cancer deaths was 1901 with a total increase rate of 127.24%. The changes in the numbers of all cancer cases and deaths, as well as the morbidity and mortality of oral cancer or all cancers also showed similar trends. Furthermore, the death-to-case ratio of oral cancers decreased from 44.23% in 2000 to 40.84% in 2020. The total decrease was 3.39% with a total decrease rate of 7.66%. In Taiwan, people's awareness of oral mucosal health is still inadequate. Obviously, there is still much room for improvement in the oral mucosal health education for our people. With the expertise and responsibility for taking good care of oral health of our people, the dental personnel should take active roles in the prevention and screening for oral cancers.

Background/purpose Langerhans cells (LCs) are antigen-presenting cells. This study mainly evaluated the LC counts in 60 odontogenic keratocysts (OKCs). Materials and methods The CD1a-positive LC numbers in the lining epithelia and subepithelial connective tissues were counted at 60 OKC sites without inflammation, 39 OKC sites with mild/moderate inflammation, and 13 OKC sites with severe inflammation from 60 OKC specimens. Results: The mean CD1a-positive LC counts in the lining epithelia and subepithelial connective tissues increased significantly from no inflammation (0.5 ± 0.4 and 0.2 ± 0.3 cell/high-power field or HPF, respectively) through mild/moderate inflammation (5.3 ± 2.5 and 2.5 ± 2.7 cells/HPF, respectively) to severe inflammation OKC sites (12.7 ± 5.6 and 9.3 ± 7.2 cells/HPF, respectively; all P-values < 0.001). OKC sites with inflammation had thicker lining epithelia than those without inflammation. Moreover, the mean CD1a-positive LC counts in the lining epithelia and subepithelial connective tissues of OKCs were significantly higher in the thicker lining epithelium (>100 μm) group (6.8 ± 5.1 and 3.7 ± 4.9 cells/HPF, respectively) than in the thinner lining epithelium (≦100 μm) group (1.0 ± 1.7 and 0.8 ± 2.5 cell/HPF, respectively; both P-values < 0.001). Conclusion: There is a significant association of inflammation grade with the number of LCs in OKCs. The scarce LCs in the lining epithelia of OKCs without inflammation suggests the loss of immunosurveillance ability against the OKC lining epithelial cells; this can explain why OKCs have aggressive clinical behavior, a great growth potential, and a high recurrence rate.