Histopathologic and immunohistochemical investigations of dental abscess formed in maxillofacial area.

BACKGROUND: An abscess is a pocket of pus that forms around the root of an infected tooth. In this study, we aimed to investigate the extracellular matrix proteases ADAMTS1, ADAMTS4, osteonectin, and osteopontin expressions in abscess fluid cells in jaws after implantation and prosthesis operation. MATERIALS AND METHODS: In this clinical study, abscess fluids belonging to 17 patients who applied to the Department of Oral and Maxillofacial Surgery were examined histopathologically and immunohistochemically. In the histopathological examination of the abscess fluid, separation of chromatin bridges in the nuclei of neutrophil cells, pyknosis and apoptotic changes in the nucleus, degenerative change in the cytoplasm, and occasional vacuolar structures were observed. RESULTS: The positive reaction of ADAMTS1 was observed in fibroblast cells, plasma cells, and macrophage cells. The positive reaction of ADAMTS4 was observed in fibroblast cells, osteoclast cells, and some apoptotic leukocyte cells. Osteopontin expression in osteoclastic cells and polymorphonuclear cells was defined as positive. Osteonectin expression was positive in polymorphonuclear leukocytes and hypertrophic fibroblast cells. CONCLUSIONS: ADAMTS1 and ADAMTS4 may induce bone destruction with its distinctive property in alveolar bone resorption, which promotes the activation of osteoclasts, which can accelerate the destruction of the extracellular matrix in the acute phase. Furthermore, osteoclastic activity increased with the increase of osteonectin and osteopontin protein expression due to inflammation in the abscess cases.

MR T1 and T2 relaxations in cysts and abscesses measured by 1.5 T MRI.

OBJECTIVES: The main objective of this study was to make a comparison between the relaxation rates in jaw cysts and abscesses. Such a comparison should provide quantitative information for MR image analysis. METHODS: A phantom containing 20 odontogenic jaw cysts and 11 jaw abscesses was imaged with 1.5 T MR. T(1) measurements were performed by using a mixed sequence of inversion recovery and spin echo, while T(2) measurements were carried out by the Carr-Purcell Meiboom-Gill (CPMG) sequence. Cystic fluids and abscesses were compared statistically. RESULTS: In cysts and abscesses, respectively, the mean 1/T(1) was 0.9355 s(-1) and 0.8245 s(-1) and the mean 1/T(2) was 2.4575 s(-1) and 4.7073 s(-1). The 1/T(2) in cysts was very highly significantly different from that in abscesses (p = 0.0001). Both T(1) and T(2) were linearly proportional to material contents. T(2) relaxivities [26.458 ml (g s)(-1) for abscesses and 21.455 ml (g s)(-1) for cysts] were higher than T(1) relaxivities [5.4766 ml (g s)(-1) for abscesses and 10.075 ml (g s)(-1) for cysts]. DISCUSSION: Present T(2) measurements differentiate cysts from abscesses with a confidence interval of 95%. Because in vivo and in vitro image contrasts are changed by the same parameters, the T(2) findings should present valuable information for in vivo MRI. Hence the significant difference and the relaxivities may provide quantitative information for clinicians and researchers making image analyses. CONCLUSION: T(2) may differentiate cysts from abscesses. The difference in T(2) is related to the material content of samples.

Determinants of MR relaxation rates in jaw cysts: implications for diagnostic values of the relaxation times.

OBJECTIVES: The MRI signal intensities and the relaxation times (T1 and T2) have already been used for comparisons among various types of cysts. The signal intensities (or T1 and T2) were suggested to be related to cyst content. However, such a relationship between the relaxation rates (1/T1 and 1/T2) and the aspirated content of jaw cysts was not given. Therefore, an investigation on the determinants of the relaxation rates in the jaw cysts may be helpful in elucidating the biological basis for the differences in relaxation rates among the categories of jaw cysts. METHODS: The aspirated contents of 23 cysts (16 radicular and 7 haemorrhagic) were scanned using an MR imager operating at 1 T magnetic field strength. The viscosities and the dry-weight-to-water-weight ratios (Ms/Mw) were determined. Also, the mean values of cyst categories were compared using statistical analysis. RESULTS: The 1/T1 had a moderate correlation with viscosity (0.66) and Ms/Mw (0.56), while the 1/T2 had a good correlation with viscosity (0.87) and Ms/Mw (0.82). The mean values of viscosity, Ms/Mw and relaxation rates in radicular cysts were significantly lower (P < 0.05) than those of haemorrhagic cysts. CONCLUSIONS: The present data suggest that similarities and differences between relaxation rates of radicular and haemorrhagic cysts can be explained by the solid content and viscosity of cysts.