Biomonitoring of DNA damage and cytotoxicity in individuals exposed to cone beam computed tomography.

OBJECTIVES: The aim of the present study was to evaluate DNA damage (micronucleus) and cellular death (pyknosis, karyolysis and karyorrhexis) in exfoliated buccal mucosa cells from adults following cone beam CT exposure. METHODS: A total of 19 healthy adults (10 men and 9 women) submitted to cone beam CT were included. RESULTS: No significant statistically differences (P > 0.05) in micronucleus frequency were seen before and after cone beam CT exposure. In contrast, the tomography was able to increase other nuclear alterations closely related to cytotoxicity such as karyorrhexis, pyknosis and karyolysis (P < 0.05). CONCLUSION: In summary, these data indicate that cone beam CT may not be a factor that induces chromosomal damage, but it is able to promote cytotoxicity.

Low-level laser therapy improves bone repair in rats treated with anti-inflammatory drugs.

Nowadays, selective cyclooxygenase-2 non-steroidal anti-inflammatory drugs have been largely used in surgical practice for reducing oedema and pain. However, the association between these drugs and laser therapy is not known up to now. Herein, the aim of this study was to evaluate the action of anti-COX-2 selective drug (celecoxib) on bone repair associated with laser therapy. A total of 64 rats underwent surgical bone defects in their tibias, being randomly distributed into four groups: Group 1) negative control; Group 2) animals treated with celecoxib; Group 3) animals treated with low-level power laser and Group 4) animals treated with celecoxib and low-level power laser. The animals were killed after 48 h, 7, 14 and 21 days. The tibias were removed for morphological, morphometric and immunohistochemistry analysis for COX-2. Statistical significant differences (P < 0.05) were observed in the quality of bone repair and quantity of formed bone between groups at 14 days after surgery for Groups 3 and 4. COX-2 immunoreactivity was more intense in bone cells for intermediate periods evaluated in the laser-exposed groups. Taken together, such results suggest that low-level laser therapy is able to improve bone repair in the tibia of rats as a result of an up-regulation for cyclooxygenase-2 expression in bone cells.

Ex vivo biocompatibility tests of regular and white forms of mineral trioxide aggregate.

AIM: To examine the genotoxicity and cytotoxicity of regular and white mineral trioxide aggregate (MTA) ex vivo by the single-cell gel (comet) assay and trypan blue exclusion test, respectively. METHODOLOGY: Aliquots of 1 x 10(4) Chinese hamster ovary cells were incubated at 37 degrees C for 3 h with grey and white forms of MTA at final concentrations ranging from 1 to 1,000 microg mL(-1). The negative control group was treated with vehicle control phosphate buffer solution for 3 h at 37 degrees C and the positive control group was treated with methyl metasulfonate (at 1 microg mL(-1)) for 1 h at 37 degrees C. After incubation, the cells were centrifuged at 180 g for 5 min and washed twice with fresh medium and resuspended with fresh medium. Each individual treatment was repeated three times consecutively to ensure reproducibility. Parameters from single-cell gel (comet) and cytotoxicity assays were assessed by the Kruskal-Wallis nonparametric test. RESULTS: Neither compounds produced genotoxic effects with respect to the single-cell gel (comet) assay in all concentrations evaluated. In the same way, the dose-response relationships of all compounds tested at concentrations ranging from 1 to 1,000 microg mL(-1) on cell viability assessed by the trypan blue assay displayed no statistically significant differences (P > 0.05) for either endodontic material. CONCLUSIONS: Regular (grey) and white MTA are not genotoxins and do not induce cellular death.

Efeito da interceptação precoce dos hábitos orais no desenvolvimento da oclusão / Effect of the early intervention of oral habits on the development of dental occlusion

BACKGROUND: Sucking habits are related to malocclusion. AIM: To evaluate the effect of a counseling interview about inhibiting this oral habit and, its influence on dental occlusion and labial-lingual posture. METHOD: 40 children (mean age = three years), with a sucking habit and anterior open bite, received counseling aiming for the interruption of this habit. Measurements of the open bite were made, as well as a myofunctional evaluation, prior to counseling and, three and six months after it. RESULTS: 26 children stopped with the habit of sucking, with 25 children presenting a reduction of the open bite. No change was observed in labial-lingual posture. CONCLUSION: The counseling interview favored the interruption of the oral habit and the correction of the open bite.

Tema: hábitos de sucção associam-se às más oclusões dentárias. Objetivo: analisar o efeito da entrevista de esclarecimento sobre a interrupção do hábito e sua influência na oclusãodentária e postura lábio-lingual. Método: 40 crianças (média de idade = três anos) com hábito de sucção e mordida aberta anterior foram orientadas visando a interrupção do hábito. Realizou-se medições da mordida aberta e avaliação miofuncional no início daorientação, três e seis meses após. Resultados: 26 crianças cessaram o hábito, com redução da mordida aberta em 25. Não houve mudança na postura lábio-lingual. Conclusão: a entrevista de esclarecimento propiciou a interrupção do hábito e a correção da mordida aberta anterior.

Periapical radiolucency mimicking an odontogenic cyst.

AIM: To present a clinical case of a giant cell lesion located in an unusual site, initially misdiagnosed and treated as an odontogenic cyst. SUMMARY: Periapical radiolucencies often suggest the presence of odontogenic pathosis, usually inflammatory granulomas or cysts. The high frequency of such lesions tends to lead clinicians to arrive at a diagnosis without completing a comprehensive assessment of the patient or carrying out the full range of available diagnostic tests. A case report of a giant cell lesion, which was misdiagnosed and treated initially as an odontogenic lesion because of its unusual location, is presented. KEY LEARNING POINTS: Clinical signs and radiographic appearance are usually sufficient to reach a diagnosis of periapical pathosis. When traditional treatment does not lead to success, a biopsy should be considered to ascertain the diagnosis and allow the correct treatment to be provided. Histological examination of soft tissue removed during endodontic surgery is essential.

Cephalometric evaluation of patients with anterior open-bite.

Cephalometric evaluations of the skeletal pattern of 30 patients with anterior open-bite malocclusion were compared to those of 30 individuals with a normal overbite. The posterior/anterior face height ratio (PFH/AFH) was the only skeletal characteristic statistically different in the two groups. The other cephalometric measurements were not found to be statistically different in the malocclusion and normal overbite groups (SN-GoGn, SN-PP, gonial angle, LFH/AFH ratio), indicating that there is no skeletal origin in the group with anterior open-bite in this study.

Bone morphology of the temporomandibular joint and its relation to dental occlusion.

The mandibular and temporal osseous components were analyzed in a sample of 30 dry skulls and their morphology was correlated with occlusal characteristics. In skulls with condyles of a more rounded shape, the depth of the fossa was greater. Furthermore, there was a significant correlation between greater depth of the fossa and skulls with normal overbite. However, no correlation was observed between depth of the fossa, tooth attrition and Spee curve.

Radiographic morphology of the temporomandibular joint related to occlusal characteristics.

The radiographic image of the temporomandibular joints of 52 individuals obtained by oblique lateral transcranial exposure was studied in terms of the appearance of the articular components (depth of the mandibular fossa, inclination of the posterior slope of the articular eminence, and condyle shape) and correlated with occlusal characteristics (overbite, tooth wear or attrition, and Spee curve). This investigation did not permit us to demonstrate a definite correlation between dental occlusion and articular morphology based on the radiographic image of the temporomandibular joint.

Tension pyopneumothorax. Rare presentation of ruptured Barrett's esophagus.

Tension pneumothorax following esophageal rupture is very rare. We report a case in which a perforated Barrett's esophagus rapidly developed a spontaneous tension pyopneumothorax. The mechanism for the tension remains obscure. Knowing that a tension pneumothorax can occur with esophageal rupture can help prevent misdiagnosis.