Caffeine induces alveolar bone loss in rats submitted to orthodontic movement via activation of receptor activator of nuclear factor Ò¡B, receptor activator of nuclear factor Ò¡B ligand, and osteoprotegerin pathway.

INTRODUCTION: Caffeine is a widely consumed substance with several effects on bone metabolism. This study aimed to investigate the effect of caffeine on the bone tissue of rats submitted to orthodontic movement. METHODS: Twenty-five male Wistar rats underwent orthodontic movement (21 days) of the first permanent maxillary molars on the left side. The experimental group (caffeine; n = 13) and control group (n = 12) received caffeine and water, respectively, by gavage. Microcomputed tomography was performed to analyze orthodontic movement. Histologic analysis of the inflammatory infiltrate and osteoclast count by tartrate-resistant acid phosphatase were conducted. Maxilla tissue was evaluated for receptor activator of nuclear factor Ò¡B (RANK), RANK ligand (RANKL), and osteoprotegerin by immunohistochemistry. RESULTS: Caffeine exhibited a lower bone volume/tissue volume ratio (78.09% ± 5.83%) than the control (86.84% ± 4.89%; P <0.05). Inflammatory infiltrate was increased in the caffeine group compared with the control group (P <0.05). A higher number of tartrate-resistant acid phosphatase-positive cells was observed in the caffeine (9.67 ± 1.73) than in the control group (2.66 ± 0.76; P <0.01). Immunoexpression of RANK and RANKL in the caffeine group was greater than the control (P <0.05). CONCLUSIONS: The use of caffeine thermogenic induces alveolar bone loss in rats submitted to orthodontic movement via activation of RANK, RANKL, and osteoprotegerin signaling pathways.

Evaluation of the Anatomic Position of the Mandibular Canal Regarding to the Segments of the Mandibular Sagittal Split Ramus Osteotomy to Diminish the Possibility of Injuries: a Pilot Study.

Objectives: This pilot study evaluated the relationship between inferior alveolar nerve location through computed tomography scan and intraoperative inferior alveolar nerve entrapment after bilateral sagittal split osteotomy. Material and Methods: Overall, 20 helicoidal computed tomography scans were evaluated in patients with facial deformities who underwent to bilateral sagittal split osteotomy (BSSO). The distance from the mandibular canal to the internal surface of the buccal and lingual cortical bone, mandibular thickness, bone density and proportion of medullary and cortical bone in 3 regions were evaluated. During the intraoperative period, the segment to which the nerve remained adhered after performing BSSO was analysed, and the data correlated. Results: The distance from the mandibular canal to the buccal cortical bone showed a mean of 2.6 mm when the inferior alveolar nerve was adhered to the distal segment and mean of 0.7 mm when the nerve was adhered to the proximal segment. The thickness was 11.2 mm and 9.8 mm when the nerve was adhered the distal the proximal segments respectively. Mandibular thickness, distance from the mandibular canal to the buccal and lingual cortical were statistically related to intraoperative nerve entrapment (P < 0.05). Conclusions: Narrow jaws and the distance from the mandibular canal to buccal cortical bone less than 2 mm increases the risk of the inferior alveolar nerve entrapment in bilateral sagittal split osteotomy.

Odontogenic Myxoma: Follow-Up of 13 cases after conservative surgical treatment and review of the literature.

BACKGROUND: We aim to report a serie of odontogenic myxoma over a 40-year period. MATERIAL AND METHODS: We conducted a retrospective and sectional review of OM cases. The clinical, radiographic and treatment data were collected from clinical records included cases whose medical records contained clinical, radiographic, histopathological, follow-up data of at least six months. RESULTS: There was a mild preference for the male with a mean age of 22.8 years. Seventy-seven percent of the lesions occurred in the posterior region of the mandible, presenting a multilocular radiolucent aspect (54%) with one presenting symptomatology. Conservative treatment was performed in all patients initially and recurrence was observed in two cases. CONCLUSIONS: Odontogenic myxoma has a well-defined clinical profile and the choice of treatment should consider aspects such as patient's age, lesion size, and location. Key words:Myxoma, odontogenic tumors, diagnosis, treatment.

Zirconia/hydroxyapatite (80/20) scaffold repair in critical size calvarial defect increased FGF-2, osteocalcin and OPG immunostaining and IL-10 levels.

The aim of this study was to characterize and evaluate zirconia/hydroxyapatite in a critical size calvarial defect model in rats. Zirconia/hydroxyapatite (80/20) scaffold was characterized by X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Critical size (8 mm) calvarial defects were created in wistar rats (n=48) and divided into four groups (90 days): G0 Group: positive control; G1 Group: hydroxyapatite; G2 Group: Zirconia; G3 Group: Zirconia/hydroxyapatite (80/20). Calvaria were subjected to Micro CT, histological and immunohistochemical analyses (RANK, RANKL, OPG, osteocalcin and FGF-2). IL-1 beta, IL-10 and TNF-alpha levels were analyzed by Elisa Immunoassay. The XRD analysis confirmed the formation of a crystalline structure and SEM showed the presence of regions corresponding to Zirconia and Hydroxyapatite. The Micro CT showed increased bone volume (BV/TV) and bone mineral density (BMD) in the G3 group (P<0.05). In addition, discrete periosteal bone formation was found at the interface of the defect edge and the external surface of the scaffold in the G3 group, showing osteocytes inside and osteoblasts (P<0.05) with scarce mononuclear inflammatory cells (P<0.01) in the central region of the defect. The immunostaining was moderate for RANKL, Osteocalcin and FGF-2 in the G3 group (P<0.5), while it was intense for OPG (P<0.001). IL-1 beta levels were decreased and IL-10 levels increased (P<0.05). Zirconia/hydroxyapatite (80/20) scaffold repair in critical size calvarial defects increased bone density, osteoblast and osteoclast cell numbers, FGF-2, osteocalcin and OPG immunostaining and IL-10 levels.

Tranexamic acid as a local hemostasis method after dental extraction in patients on warfarin: a randomized controlled clinical study.

OBJECTIVES: The present work is a controlled, blinded, and randomized clinical trial comparing hemostatic measures for the control of post-tooth extraction hemorrhage in patients on anticoagulation therapy with warfarin. MATERIALS AND METHODS: The sample consisted of 37 patients (37.8% male and 62.2% female) with a mean age of 45.5 years. After randomization, 20 patients were allocated to the control group (conventional hemostasis measures) and 17 to the study group (addition of local tranexamic acid). All variables that could influence the outcome were similar between the groups and no significant difference was seen (p > 0.05). RESULTS: In the assessment of immediate hemostasis, for the control group, the time to achieve cessation of bleeding was 9.1 (± 3.6) minutes. For the study group this was much lower, and this difference (6.018 / confidence interval of 95%, 4.677 to 7.359) was statistically significant (p < 0.001). In evaluating the control of intermediate hemorrhage, the use of tranexamic acid was more significantly associated with the absence of bleeding, especially in the first 24 h. CONCLUSIONS AND CLINICAL RELEVANCE: Thus, this measure of local hemostasis in topical form with gauze compression and irrigation was shown to be more effective in reducing the time to attain immediate hemostasis, and in preventing intermediate hemorrhage.

Low-level laser therapy (780 nm) combined with collagen sponge scaffold promotes repair of rat cranial critical-size defects and increases TGF-ß, FGF-2, OPG/RANK and osteocalcin expression.

The aim of this study was to evaluate the effect of collagen sponge scaffold (CSS) implantation associated with low-level laser therapy (LLLT) on repairing bone defects. A single 5-mm cranial defect was surgically created in forty Wistar rats, which then received one of the following four interventions (n = 10 per group): no treatment (G0); bone defect implanted with collagen sponge scaffold (CSS) alone (G1); defect treated with low-level laser therapy (LLLT) (wavelength 780 nm; total energy density 120 J/cm2 ; power 50 mW) alone (G2); and CSS associated with LLLT treatment (G3). After surgery, animals in each group were euthanized at 21 days and 30 days (n = 5 per euthanasia time group). Bone formation was monitored by X-ray imaging analysis. Biopsies were collected and processed for histological analysis and immunohistochemical evaluation of transforming growth factor-beta (TGF-ß), fibroblast growth factor-2 (FGF-2), osteoprotegerin (OPG) and receptor activator of nuclear factor ƙ (RANK). Osteocalcin (OCN) was detected by immunofluorescence analysis. Compared to the G0 group, defects in the 30-day G3 group exhibited increased bone formation, both by increase in radiopaque areas (P < 0.01) and by histomorphometric analysis (P < 0.001). The histopathological analysis showed a decreased number of inflammatory cells (P < 0.001). The combined CCS + LLLT (G3) treatment also resulted in the most intense immunostaining for OPG, RANK, FGF-2 and TGF-ß, and the most intense and diffuse OCN immunofluorescent labelling at 30 days postsurgery (G3 vs. G0 group, P < 0.05). Therefore, the use of CCS associated with LLLT could offer a synergistic advantage in improving the healing of bone fractures.

Factors associated to post-operative nausea and vomiting following oral and maxillofacial surgery: a prospective study.

AIM: This study aims to address and assess possible factors associated with nausea and vomiting (NV) following oral and maxillofacial surgery. MATERIAL AND METHODS: A prospective study was carried out in the period from December 2013 to January 2016 targeting all attended cases in that period. For statistical analysis, Pearson chi-square and Fisher tests were used to verify association and ANOVA and Student's t tests to test for significant difference, p was defined as ≤0.05. The sample group consisted of 207 patients with an average age of 33.56 years (±13.23), and 70.5% of subjects were male. RESULTS: Calculations based on the predictive model showed that a female patient with prior history of nausea and vomiting who used opioids and had intra-oral surgical access would have a 96% chance of experiencing a nausea and vomiting episode. Other factors like age, being overweight, anesthesia, surgery duration, and duration of hospital stay also contribute so that these aspects must be paid careful attention prior to surgery to ensure a suitably orientated treatment that will avoid disturbances caused by post-operative nausea and vomiting. CONCLUSION: The occurrence of post-operative nausea and vomiting after oral and maxillofacial surgery was found to be more higher incidence associated to female patients who used opioids, who had a prior history of NV, whose surgery involved intra-oral access, who were in the second or third decades of their lives, who have above average weight, and who have long anesthesia when undergoing surgery, resulting in a long hospital stays.

Large solitary fibrous tumor of the oral cavity--report of a case.

The solitary fibrous tumor (SFT) is a rare soft tissue tumor with a substantially benign clinical behavior. The SFT of the oral cavity is a very uncommon entity. It is also of complicated diagnosis because of its extensive morphologic diversity and because of its similarity to many mesenchymal tumors. A 44-year-old man was referred for management of an asymptomatic lesion in the left buccal mucosa, which had been identified 10 years earlier. Intra-oral examination revealed a well-demarcated, fibroelastic, rounded exophytic mass located in the left buccal mucosa. The mass was covered with a non-ulcerated mucosa of normal color and measured approximately 4.0 cm in diameter. Histopathological examination showed proliferation of spindle-shaped cells arranged in fascicles and in a patternless pattern, highly vascularized, with focal staghorn vessels. Immunohistochemical analysis revealed diffuse positivity for CD34 and focal positivity for Bcl-2. Awareness of the morphological diversity of SFT coupled to a judicious use of appropriate immunohistochemical probes should prove valuable to accurately segregate SFT from other spindle cell neoplasms.

External apical root resorption in retracted incisors.

AIM: To evaluate the occurrence of external apical root resorption (EARR) in the incisors after anterior retraction in corrective orthodontic treatment with first premolar extractions and whether it was related with the type of root apex movement and its inclination. METHOD: The maxillary and mandibular incisors of 22 patients (12 to 25 years of age; 9 males and 13 females) were treated with fixed appliances and premolar extraction. EARR was defined as the difference in root length before and after incisal retraction on periapical radiographs. Distortion of radiographic images and changes due to incisal tipping were controlled for. Pre- and post-incisal retraction lateral cephalometric radiographs established the relationship between EARR and the tipping of the incisors, along with the vertical, horizontal, and total movement of the root apex. RESULTS: There was significant EARR (1.51 to 2.37 mm) during incisor retraction, but this was not related to the movement or the tipping of the root apex of almost all teeth. It was observed that after the retraction stage, EARR occurred in all evaluated incisors, but it was more significant (P < .05) in the mandibular right lateral incisor. CONCLUSION: The EARR that did occur was unrelated to movement or tipping of the root apex, except for the vertical root apex movement of the mandibular left central incisor and the inclination of the maxillary right lateral incisor.

Osteoblastlike cell adhesion on titanium surfaces modified by plasma nitriding.

PURPOSE: The aim of this study was to evaluate the characteristics of various titanium surfaces modified by cold plasma nitriding in terms of adhesion and proliferation of rat osteoblastlike cells. MATERIALS AND METHODS: Samples of grade 2 titanium were subjected to three different surface modification processes: polishing, nitriding by plasma direct current, and nitriding by cathodic cage discharge. To evaluate the effect of the surface treatment on the cellular response, the adhesion and proliferation of osteoblastlike cells (MC3T3) were quantified and the results were analyzed by Kruskal-Wallis and Friedman statistical tests. Cellular morphology was observed by scanning electron microscopy. RESULTS: There was more MC3T3 cell attachment on the rougher surfaces produced by cathodic cage discharge compared with polished samples (P < .05). CONCLUSIONS: Plasma nitriding improves titanium surface roughness and wettability, leading to osteoblastlike cell adhesion.