Bone healing pattern in surgically created circumferential defects around submerged implants: an experimental study in dog

Objective: To describe the healing of marginal defects below or above 1 mm of dimension around submerged implants in a dog model. Material and methods: In 12 Labrador dogs, all mandibular premolars and first molars were extracted bilaterally. After 3 months of healing, full‐thickness flaps were elevated in the edentulous region of the right side of the mandible. Two recipient sites were prepared and the marginal 5 mm were widened to such an extent to obtain, after implant installation, a marginal gap of 0.5 mm at the mesial site (small defect) and of 1.25 mm at the distal site (large defect). Titanium healing caps were affixed to the implants and the flaps were sutured allowing a fully submerged healing. The experimental procedures were subsequently performed in the left side of the mandible. The timing of the experiments and sacrifices were planned in such a way to obtain biopsies representing the healing after 5, 10, 20 and 30 days. Ground sections were prepared and histomorphometrically analyzed. Results: The filling of the defect with newly formed bone was incomplete after 1 month of healing in all specimens. Bone formation occurred from the base and the lateral walls of the defects. A larger volume of new bone was formed in the large compared with the small defects. Most of the new bone at the large defect was formed between the 10‐ and the 20‐day period of healing. After 1 month of healing, the outline of the newly formed bone was, however, located at a similar distance from the implant surface (about 0.4 mm) at both defect types. Only minor newly formed bone in contact with the implant, starting from the base of the defects, was seen at the large defects (about 0.8 mm) while a larger amount was detected at the small defects (about 2.2 mm). Conclusion: Marginal defects around titanium implants appeared to regenerate in 20–30 days by means of a distance osteogenesis. The bone fill of the defects was, however, incomplete after 1 month. To cite this article:
Rossi F, Botticelli D, Pantani F, Pereira FP, Salata LA, Lang NP. Bone healing pattern in surgically created circumferential defects around submerged implants: an experimental study in dog.
Clin. Oral Impl. Res 23 , 2012; 41–48.
doi: 10.1111/j.1600‐0501.2011.02170.x     

Development of a model of soft tissue simulation using ballistic gelatin for CBCT acquisitions related to dentomaxillofacial radiology research

Objectives:To present the ballistic gelatin as a new material capable of simulating the soft tissues in cone-beam CT (CBCT) images.Methods:CBCT images of three piglet heads were acquired with their soft tissues intact (standard group). Subsequently, the piglet heads were fixed in a container using metallic pins and moulded with acrylic resin; the soft tissues were then removed and replaced by ballistic gelatin, with the same thickness of the original soft tissues. The images were evaluated by two oral radiologists, to check the adaptation on bone surfaces, thickness and density, penetration into large bone cavities and cancellous bone, and the presence of air bubbles using a 5-score scale. Additionally, an objective analysis was carried out by one oral radiologist. For each CBCT scan, three axial reconstructions were selected to represent the mandibular, occlusal, and maxillary levels. The mean and standard deviation (SD) of the grey values were calculated in four regions of interest determined on soft tissue areas and compared by two-way ANOVA.Results:The ballistic gelatin showed subjective scores ranging from good to excellent for all parameters evaluated. There was no significant difference in the mean and SD values of the grey values between ballistic gelatin and the gold standard groups for all levels (p > 0.05). Higher SD values were observed in the occlusal level for both groups (p < 0.05).Conclusions:Ballistic gelatin has visual and objective similarity with the gold standard. Thus, the ballistic gelatin is a promising material capable of simulating soft tissues in CBCT images.     

Analysis of oral risk factors for ventilator-associated pneumonia in critically ill patients

Clinical Oral Investigations - This a cross-sectional study to evaluate the association between oral health findings and ventilator-associated pneumonia (VAP) among critically ill patients in...     

Heteroresistance to Itraconazole Alters the Morphology and Increases the Virulence of Cryptococcus gattii

Cryptococcus gattii is the main etiological agent of cryptococcosis in immunocompetent individuals. The triazole drug itraconazole is one of the antifungals used to treat patients with cryptococcosis. Heteroresistance is an adaptive mechanism to counteract the stress of increasing drug concentrations, and it can enhance the ability of a microorganism to survive under antifungal pressure. In this study, we evaluated the ability of 11 C. gattii strains to develop itraconazole heteroresistance. Heteroresistant clones were analyzed for drug susceptibility, alterations in cell diameter, capsule properties, and virulence in a murine model. Heteroresistance to itraconazole was intrinsic in all of the strains analyzed, reduced both the capsule size and the cell diameter, induced molecular heterogeneity at the chromosomal level, changed the negatively charged cells, reduced ergosterol content, and improved the antioxidant system. A positive correlation between surface/volume ratio of original cells and the level of heteroresistance to itraconazole (LHI) was observed in addition to a negative correlation between capsule size of heteroresistant clones and LHI. Moreover, heteroresistance to itraconazole increased the engulfment of C. gattii by macrophages and augmented fungal proliferation inside these cells, which probably accounted for the reduced survival of the mice infected with the heteroresistant clones and the higher fungal burden in lungs and brain. Our results indicate that heteroresistance to itraconazole is intrinsic and increases the virulence of C. gattii. This phenomenon may represent an additional mechanism that contributes to relapses of cryptococcosis in patients during itraconazole therapy.     

Psammomatoid juvenile ossifying fibroma: an analysis of 2 cases affecting the mandible with review of the literature

Juvenile ossifying fibroma (JOF) is a rare fibro-osseous neoplasm, defined as a variant of the ossifying fibroma that arises within the craniofacial bones. Two subgroups, juvenile psammomatoid ossifying fibroma (PsJOF) and juvenile trabecular ossifying fibroma, have been delineated by their histology. PsJOF occurs predominantly in the sinonasal and orbital bones. This work reports on 2 cases of extensive PsJOF in the body of the right mandible as well as reviews the literature regarding the radiographic and histologic features, treatment, and prognosis of PsJOF of the jaws.     

Influence of tinnitus on pain severity and quality of life in patients with temporomandibular disorders

Objective

The aim of this cross-sectional study was to evaluate the relationship among pain intensity and duration, presence of tinnitus and quality of life in patients with chronic temporomandibular disorders (TMD).

Material and Methods

Fifty-nine female patients presenting with chronic TMD were selected from those seeking for treatment at the Bauru School of Dentistry Orofacial Pain Center. Patients were submitted to the Research Diagnostic Criteria anamnesis and physical examination. Visual analog scale was used to evaluate the pain intensity while pain duration was assessed by interview. Oral Health Impact Profile inventory modified for patients with orofacial pain was used to evaluate the patients'' quality of life. The presence of tinnitus was assessed by self report. The patients were divided into: with or without self report of tinnitus. The data were analyzed statistically using the Student''s t-test and Pearson''s Chi-square test, with a level of significance of 5%.

Results

The mean age for the sample was 35.25 years, without statistically significant difference between groups. Thirty-two patients (54.24%) reported the presence of tinnitus. The mean pain intensity by visual analog scale was 77.10 and 73.74 for the groups with and without tinnitus, respectively. The mean pain duration was 76.12 months and 65.11 months for the groups with and without tinnitus, respectively. The mean OHIP score was 11.72 and 11.74 for the groups with and without tinnitus, respectively. There was no statistically significant difference between groups for pain intensity, pain duration and OHIP scoreS (p>0.05).

Conclusion

Chronic TMD pain seems to play a more significant role in patient''s quality of life than the presence of tinnitus.     

Activity of alemtuzumab monotherapy in treatment-naive, relapsed, and refractory severe acquired aplastic anemia

Antithymocyte globulin (ATG) + cyclosporine is effective in restoring hematopoiesis in severe aplastic anemia (SAA). We hypothesized that the humanized anti-CD52 mAb alemtuzumab might be active in SAA because of its lymphocytotoxic properties. We investigated alemtuzumab monotherapy from 2003-2010 in treatment-naive, relapsed, and refractory SAA in 3 separate research protocols at the National Institutes of Health. Primary outcome was hematologic response at 6 months. For refractory disease, patients were randomized between rabbit ATG + cyclosporine (n = 27) and alemtuzumab (n = 27); the response rate for alemtuzumab was 37% (95% confidence interval [CI], 18%-57%) and for rabbit ATG 33% (95% CI, 14%-52%; P = .78). The 3-year survival was 83% (95% CI, 68%-99%) for alemtuzumab and 60% (95% CI, 43%-85%) for rabbit ATG (P = .16). For relapsed disease (n = 25), alemtuzumab was administered in a single-arm study; the response rate was 56% (95% CI, 35%-77%) and the 3-year survival was 86% (95% CI, 72%-100%). In treatment-naive patients (n = 16), alemtuzumab was compared with horse and rabbit ATG in a 3-arm randomized study; the response rate was 19% (95% CI 0%-40%), and the alemtuzumab arm was discontinued early. We conclude that alemtuzumab is effective in SAA, but best results are obtained in the relapsed and refractory settings. The present trials were registered at www.clinicaltrials.gov as NCT00195624, NCT00260689, and NCT00065260.