Comparison of different bone substitutes in the repair of rat calvaria critical size defects: questioning the need for alveolar ridge presentation.

OBJECTIVE: This study aimed to evaluate the effectiveness of biomaterials in bone healing of critical bone defects created by piezoelectric surgery in rat calvaria. METHOD AND MATERIALS: Histomorphologic analysis was performed to assess bone regeneration and tissue response. Fifty animals were randomized into five groups with one of the following treatments: Control group (n = 10), spontaneous blood clot formation with no bone fill; BO group (Bio-Oss, Geistlich Pharma; n = 10), defects were filled with bovine medullary bone substitute; BF group (Bonefill, Bionnovation; n = 10), defects were filled with bovine cortical bone substitute; hydroxyapatite group (n = 10), defects were filled with hydroxyapatite; calcium sulfate group (n = 10), defects were filled with calcium sulfate. Five animals from each group were euthanized at 30 and 45 days. The histomorphometry calculated the percentage of the new bone formation in the bone defect. RESULTS: All data obtained were evaluated statistically considering P < .05 as statistically significant. The results demonstrated the potential of all biomaterials for enhancing bone regeneration. The findings showed no statistical differences between all the biomaterials at 30 and 45 days including the control group without bone grafting. CONCLUSION: In conclusion, the tested biomaterials presented an estimated capacity of osteoconduction, statistically nonsignificant between them. In addition, the selection of biomaterial should consider the specific clinical aspect, resorption rates, size of the particle, and desired bone healing responses. It is important to emphasize that in some cases, using no bone filler might provide comparable results with reduced cost and possible complications questioning the very frequent use of ridge presentation procedures.

A randomised trial of the bone formation after maxillary sinus floor augmentation with bovine hydroxyapatite (Cerabone®) and Photobiomodulation: histomorphometric and immunohistochemical analysis.

Background: The use of non-autogenous biomaterial to increase bone height in the maxillary sinus has been shown to be effective, but the results are still inconclusive. Material and Methods: Eight participants were selected and included in the research. After surgical access with osteotomy on the lateral wall of both maxillary sinuses, these were filled with Cerabone®. Then, by blind randomization, they received one of the following treatments: Filling with Cerabone® (Control group); treatment with Photobiomodulation (PBM), filling with Cerabone® and treatment with low-power laser (PBM group). Biopsies were obtained 30 days after the surgery, using a 2.8 mm internal diameter trephine bur. Qualitative and quantitative histological analyzes were performed and immunohistochemical analyzes of osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) were performed with scores for each of the biological events. Results: The Cerabone® biomaterial demonstrated a high degree of biocompatibility. New bone formation was observed in both groups. In the PBM group, there was greater bone formation and newly formed tissue in an advanced state of bone maturation. The immunostaining of OCN was greater at 30 days in the PBM group than in the control. There was no significant difference in TRAP immunostaining at 30 days between the groups. Conclusions: Low-power laser-mediated by PBM promoted greater bone formation; the newly formed tissue showed a more advanced state of bone maturation in maxillary sinuses filled with Cerabone® biomaterial and treatment with PBM, within the 30-day evaluation period. Key words:Sinus floor augmentation, dental implants, bone and bones, low-level light therapy.

The Risk of Osseointegration in the Coronavirus Disease 19 Pandemic.

ABSTRACT: Coronavirus disease 19 (COVID-19) is associated with respiratory complications but also with alterations on bone metabolism. Coronavirus disease 19, therefore, might be a risk factor for osseointegration. Recent studies suggest that severe acute respiratory syndrome coronavirus 2 is related with bone abnormalities mainly for act via renin-angiotensin system. This report aims to list the bone alterations caused by coronavirus disease 19 and the possible consequences on the peri-implant bone healing. The current data add to the accumulating knowledge that coronavirus disease 19 may negatively impact the osseointegration and it requires further research.

Technical Strategy of Bone Graft Augmentation in the Anterior Maxilla.

Bone graft augmentation in the anterior maxilla has a high successful rate. However, suture dehiscence and consequent bone graft exposure can compromise and fail this procedure. Therefore, this article presents a new strategy of closure technique to guarantee the bone graft augmentation. The sutures occur in muscular and mucous planes to avoid suture tension, thus decreasing complications of bone graft augmentation in the anterior maxilla.

Strategy of Mandibular Central Arch Reconstruction After Firearm Injury.

Gunshot wounds can cause extensive destruction of soft tissue and bone, and the maxillofacial region is often affected. The reconstructive treatment is complex due to the difficulty to reestablish the central arch mandibular contour and volume. Moreover, the goal is to avoid postoperative infections and obtain bone graft neovascularization. Therefore, this report shows a clinical case of a patient presenting mandibular deformity with a mandibular central arch discontinuity caused by a firearm injury. The strategy to the reconstructive treatment as performed with a condensed and stabilized particulate autogenous bone graft was essential and effectiveness. After 1 year, it was obtained a satisfactory result to the patient.

Losartan improves alveolar bone dynamics in normotensive rats but not in hypertensive rats

Abstract Hypertension is one of the main causes of premature death in the world; also, it is associated with several bone alterations. Preclinical studies have demonstrated delayed alveolar bone healing in hypertensive rats. However, losartan has been favorable for consolidation of bone grafts and reduction in active periodontitis. Therefore, losartan is suggested to be effective in bone formation stages, as well as in the synthesis of matrix proteins and mineralization. Objectives: To evaluate the alveolar bone dynamics in hypertensive rats treated with losartan by laser confocal microscopy and histological analysis. Methodology: Thirty-two rats, 16 spontaneously hypertensive rats (SHR) and 16 Wistar albinus rats, treated or not with losartan (30 mg/kg/day) were used. Calcein fluorochrome at 21 days and alizarin red fluorochrome at 49 days were injected in rats (both 20 mg/kg). The animals were submitted to euthanasia 67 days after treatment, and then the right maxilla was removed for laser confocal microscopy analysis and the left maxilla for histological analysis. Results: This study showed a greater calcium marking in normotensive animals treated with losartan in relation to the other groups. Laser confocal microscopy parameters showed higher values of bone volume formed, mineralized surface, active surface of mineralization and bone formation rate in normotensive animals treated with losartan. However, a smaller mineralized surface was observed in all hypertensive animals. Conclusion: Losartan can improve bone mineralization parameters under normal physiological conditions, but the same anabolic effect does not occur under hypertension.

Orbital Emphysema: A Rare Postoperative Complication.

Orbital emphysema can be a rare and severe postoperative complication. Fast and critical diagnosis is essential to avoid permanent visual loss to the patient. Therefore, a case of a male patient victim of a motorcycle accident with a postoperative complication of orbital emphysema has been presented. The immediate diagnosis and treatment of the orbital emphysema revealed to be the main success factors for the resolution of this complication.

Upper Airway Obstruction in a Panfacial Fracture.

Panfacial fractures are considered the most aggressive and complex facial fracture, and most of them are the results of a high energy trauma. Therefore, a clinical report of a male patient with a panfacial fracture and Richards type 3 fracture resulting in an airway obstruction is presented. This type of fracture can promote an upper airway obstruction, which needs a correct and fast diagnosis to the life support of the patient.

Immediate Treatment of Complex Mandible Fracture in a Pediatric Patient.

The facial fractures in pediatric patients are rare, and they can need an immediate treatment to recover the function and aesthetic to the young patients. However, the open reduction internal fixation is controversial in pediatrics; it can be effectiveness to treat complex mandible fractures. Therefore, we present a case of a pediatric patient with a complex mandible fracture caused by an auto accident. The immediate treatment was successful with the use of open reduction internal fixation.

Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis.

INTRODUCTION: Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. OBJECTIVES: The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis. MATERIAL AND METHODS: Thirty animals (Rattus norvegicus, Albinus Wistar) were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG), receptor activator of nuclear kappa B ligand (RANKL) and tartrate resistant acid phosphate (TRAP) was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2), osteocalcin (OC), osteopontin (OPN), osterix (OST) and receptor activator of nuclear kappa B (RANK) were performed to determine the expression of these proteins in the alveolar bone healing. RESULTS: Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. CONCLUSION: Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic multicellular units during the alveolar bone healing.

Short-Blunt Injury in Child Resulting From Pet Bite.

The frequency of accidents due to dog bite in children is high, and in the most cases, the child already knows the aggressor dog. Patient, 3 years, female, melanoderm, victim of pet dog attack on the right side of the face region. After the physical examination, conscious sedation was performed with the supplementation of oxygen by pediatrics and the suture by oral and maxillofacial surgeon, under local anesthesia with adrenergic vasoconstrictor, with internal points in the muscles using vicryl 4-0 and in the skin with 5-0 nylon; the lesser number of stitches were performed in the lower region of the wound, allowing spontaneous drainage spaces. The immediate wounds closure of dog bites on the face is safe, even in cases after several hours of the injury.

Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis

Abstract Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. Objectives The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis. Material and Methods Thirty animals (Rattus norvegicus, Albinus Wistar) were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG), receptor activator of nuclear kappa B ligand (RANKL) and tartrate resistant acid phosphate (TRAP) was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2), osteocalcin (OC), osteopontin (OPN), osterix (OST) and receptor activator of nuclear kappa B (RANK) were performed to determine the expression of these proteins in the alveolar bone healing. Results Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. Conclusion Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic multicellular units during the alveolar bone healing.

Morphometric and histologic characterization of alveolar bone from hypertensive patients.

BACKGROUND: Hypertension is considered a risk factor in implant dentistry but the underlying reasons remain unclear. It may be that hypertension has a negative impact on the local bone quality. PURPOSE: Here we evaluated the structural and histological parameters of bone collected from hypertensive patients treated by antagonists of the renin-angiotensin system, and of bone collected from normotensive patients. MATERIAL AND METHODS: A total of 30 patients were referred for rehabilitation with dental implants to be placed in the posterior mandible. The first group were hypertensive patients treated with RAS antagonists. The second group were normotensive patients not taking medication. Bone biopsies collected during implant installation were subjected to analysis. Micro CT revealed the structural parameters. Histological analyses together with immunohistochemical staining of osteogenic markers were performed. RESULTS: The structural parameters of bone volume, trabecular thickness, trabecular number, separation of the trabecular, and total porosity were similar between the 2 groups (P > .05). The histological appearance of bone derived from hypertensive patients was normal. The staining pattern of Runx-2, osteopontin, and osteocalcin were comparable in both groups. CONCLUSIONS: These observations suggest that hypertensive patients treated with renin-angiotensin system antagonists have regular alveolar bone with respect to bone structure and histological parameters.

Andy Gump Fracture of the Mandible in a Pediatric Patient.

The mandibular fractures in pediatric patients are rare, and they can need a fast and safe treatment. We present a case of a pediatric patient with "Andy Gump" fracture, resulting in a retrognathic mandible, distress to breathe, and functional discomfort to the patient caused by a cycling accident. The treatment was successful with the fast release of airway path and use of titanium plates to fix the fracture.

Diagnosis and Management of Cerebrospinal Fluid Leak in a Panfacial Fracture.

Cerebrospinal fluid fistula caused by head trauma is a potentially dangerous problem and precise localization and radical treatment are necessary. We present a case of a patient with Panfacial fracture caused by a motorcycle accident, resulting in a cerebrospinal fluid leakage. The correct diagnosis was realized by computed tomography and auxiliary tests. The successful treatment can be confirmed with the support of radionuclide cisternography examination.