RESUMEN
Statement of the Problem: Odontogenic keratocyst [OKC] is a developmental odontogenic cyst with specific histopathological features, high recurrence rate, and aggressive clinical behavior. Angiogenesis might be considered as an important factor for the growth, expansion, and distribution of this lesion
Purpose: The aim of the present study was to determine the mean vascular densities [MVD] of OKCs and dentigerous cysts to evaluate their relationship with the biolog-ic behavior of these lesions
Materials and Method: In this cross-sectional analytical study, angiogenesis was assessed in OKC and dentigerous cyst by measuring the MVD. Immunohistochemis-try was carried out using CD34 and CD105. The results were analyzed with inde-pendent samples t-test. The data were analyzed, setting p value at 0.05
Results: The MVDs with the use of CD34 and CD105 markers were significantly higher in OKC compared to dentigerous cyst [p< 0.05]. In addition, MVDs obtained by CD105 in dentigerous cysts and OKC were significantly less than those based on CD34 [p< 0.05]
Conclusion: Based on the results of the present study, it can be suggested that angi-ogenesis might be one of the possible mechanisms involved in higher aggressive biologic behavior and greater recurrence rate of OKC compared to dentigerous cysts
RESUMEN
Statement of the Problem: Stem cells are considered as new implement for tissue regeneration. Several niches in adult human body are colonized by multipotent stem cells but access to these potential reservoirs is often limited. Although human dental pulp stem cells isolated from healthy teeth have been extensively characterized, it is still unknown whether stem cells also exist in reactive lesions of oral cavity such as pyogenic granuloma and peripheral ossifying fibroma which are deliberated as inflammatory proliferation of different cell families
Purpose: The aim of this study was to explore for clues to see whether pyogenic granuloma or peripheral ossifying fibroma contain dental mesenchymal stem cell [DMSC]
Materials and Method: Four pyogenic granuloma and four peripheral ossifying fibroma specimens were collected by excisional biopsy and preserved in PBS-EDTA at -86 [degree]C. Then we cut them in 5?m diameter using Cryostat. Having been rinsed with PBS, the samples were stained with a primary mouse anti-human STRO-1 monoclonal IgM antibody. Afterward, a secondary goat anti-mouse IgM-FITC antibody was applied to detect STRO-1+ cells as probable stem cells by immunofluorescence technique
Results: Immunofluorescence microscopy revealed presence of STRO-1+ cells in these lesions, particularly localized on perivascular zone. The negative control group was not glowing
Conclusion: Based on these results, it was found that reactive lesions of pyogenic granuloma and peripheral ossifying fibroma have STRO-1 positive cells, which raises the possibility that these cells may be DMSCs
RESUMEN
Statement of the Problem: Fixed retainers were developed to maintain incisor alignments after orthodontic treatments. Although the effects of fixed retainers on periodontal health are clinically studied, no studies have still evaluated the histological changes in the periodontium after the placement of thefixed retainers
Purpose: The aim of this study was to evaluate the effects of customised retainers on periodontium histologically
Materials and Method: Forty pairs of maxillary and mandibular central incisors of twenty rabbits were randomly divided into four equal groups: The first group was considered as the control and in the second group, Fiber Reinforced Composite [FRC], in the third group, 0.014 inch stainless steel [SS] wire and in the fourth group, 0.175 inch multistrand stainless steel [MSS] wire were bonded on the labial surfaces of the incisors. After sixty days; animals' periodontium were evaluated histologically
Results: The number of bone resorption lacuna in the control group was significantly less than FRC and 0.014 SS groups. The periodontal vessel count and their diameter in the control group was significantly lower than the other groups. The pulp vessel count and their diameter in controls were significantly more than the 0.014 SS and the 0.175 MSS groups
Conclusion: Findings of this study suggest that FRC fixed retainer might cause detrimental effects on the periodontal ligaments and supporting bone and the 0.014- inch and 0.175- inch fixed retainers can cause hyalinization and possibly the necrosis of the pulp
RESUMEN
Statement of the Problem: Alveolar bone necrosis induced by Herpes zoster infection is considered as a rare manifestation of osteomyelitis and few case reports are presented in the literature
Purpose: The aim of this study was to evaluate mandibular osteomyelitis caused by herpes zoster in the immunocompromised patients with histopathologically documented osteomyelitis in the mandible and herpes zoster infection
Materials and Method: 30 patients were recruited in this cross-sectional study. 19 patients were completely edentulous, 4 patients were partially edentulous and 7 with complete dentition. In all cases, specimens were analyzed using a conventional polymerase chain reaction [PCR] test for varicella zoster virus
Results: 16 patients underwent dialysis, 9 patients received chemotherapy treatments and 5 patients had transplantation [four kidneys and one liver]. Histopathological assessment demonstrated a nonspecific bone necrosis exhibiting an eosinophilic, homogeneous non-vital bone tissue with peripheral resorption surrounded by reactive connective tissue. PCR test was positive in 21 cases
Conclusion: This study demonstrated that the frequency of osteomyelitis induced by herpes zoster could be more than the records provided by previous studies. Histopathological findings might be nonspecific in such patients. PCR test was not positive for all HZ induced osteomyelitis patients