Sex dependent differences of temporomandibular condylar bone mineral density distribution.

OBJECTIVE: The objective of this study was to examine whether bone mineral density (BMD) distribution in the mandibular condyle and facial morphology are associated with temporomandibular joint osteoarthritis (TMJ OA) using clinical cone beam computed tomography (CBCT) images. METHODS: CBCT images of 35 adults (16 male and 19 female) were examined to obtain TMJ OA counts, cephalometric analyses, and histograms of gray values that are proportional to BMD. Mean, standard deviation (SD), and low and high gray values at the 5th and 95th percentiles (Low5 and High5) of the histograms were measured. RESULTS: The female group had significantly higher values of TMJ OA counts, mean, and SD on the right mandibular condyle, High5 on both sides, and all gray value parameters for total (right + left) than the male group. CONCLUSION: Comprehensive analysis of BMD distribution in the mandibular condyle can provide useful information for prognosis of TMJ OA.

Alendronate-induced Perturbation of the Bone Proteome and Microenvironmental Pathophysiology.

Objectives: Bisphosphonates (BPs) are powerful inhibitors of osteoclastogenesis and are used to prevent osteoporotic bone loss and reduce the risk of osteoporotic fracture in patients suffering from postmenopausal osteoporosis. Patients with breast cancer or gynecological malignancies being treated with BPs or those receiving bone-targeted therapy for metastatic prostate cancer are at increased risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Although BPs markedly ameliorate osteoporosis, their adverse effects largely limit the clinical application of these drugs. This study focused on providing a deeper understanding of one of the most popular BPs, the alendronate (ALN)-induced perturbation of the bone proteome and microenvironmental pathophysiology. Methods: To understand the molecular mechanisms underlying ALN-induced side-effects, an unbiased and global proteomics approach combined with big data bioinformatics was applied. This was followed by biochemical and functional analyses to determine the clinicopathological mechanisms affected by ALN. Results: The findings from this proteomics study suggest that the RIPK3/Wnt/GSK3/ß-catenin signaling pathway is significantly perturbed upon ALN treatment, resulting in abnormal angiogenesis, inflammation, anabolism, remodeling, and mineralization in bone cells in an in vitro cell culture system. Conclusion: Our investigation into potential key signaling mechanisms in response to ALN provides a rational basis for suppressing BP-induced adverse effect and presents various therapeutic strategies.

Oral Findings of Erdheim-Chester Disease: A Case Report and Review of the Literature.

Erdheim-Chester Disease (ECD) is a rare non-Langerhans cell histiocytosis characterized by histiocytic infiltration of multiple organ systems, including the bony skeleton, central nervous system, cardiovascular system, lungs, and kidneys. Manifestations of the disease are highly variable, ranging from focal disease to multisystem involvement. Oral manifestations are exceedingly rare, with only 10 known reports of ECD involving the jaws. The objective of this case report is to highlight the radiographic, clinical, and histological features of ECD involving the maxillofacial complex. A 35-year-old male admitted for sepsis secondary to pyelonephritis and suspected diabetes insipidus received an extensive workup for ECD versus IgG4 disease versus lymphoma. The oral-maxillofacial surgery service was consulted for biopsy of maxillary lesions noted to have increased activity on positron emission tomography. Intraoral biopsy yielded the characteristic histopathological features of ECD, confirming the diagnosis. We compare the clinical, radiographic, and microscopic features of ECD with past findings, contributing to the profile of this rare disease.

Enhancement of bone marrow aspirate concentrate with local self-healing corticotomies.

Bone marrow aspirate concentrate (BMAC) is a potentially useful biological product for bone regeneration. This study investigated whether BMAC can be enriched by local minor corticotomies. Five 4-month-old domestic pigs were used with each pig undergoing two minor corticotomies at one randomly-selected tibia. Two weeks after the operation, bone marrow was aspirated from both tibiae and processed into BMAC samples. The amount of mesenchymal stem cells (MSCs) and the concentration of several regenerative growth factors contained in BMAC, as well as the proliferative and osteogenic differentiation capacity of MSCs, were compared between the corticotomy and the control sides. Another four weeks later, healing of the corticotomies was evaluated by radiographic and histological methods. The results demonstrated that BMAC from the corticotomy side contained significantly more MSCs than the control side. MSCs from the corticotomy side also proliferated significantly faster and tended to have stronger osteogenic differentiation than those from the control side. In contrast, the protein concentration of TGF-ß, BMP-2 and PDGF contained in BMAC was only minimally changed by the corticotomies. The corticotomies in all pigs healed uneventfully, showing complete obliteration of the corticotomy gaps on CT images. Comparison between the two sides showed that the corticotomy side had thicker and denser cortical bone and more abundant osteogenic cell differentiation than the control side. These findings suggest that the quantity and proliferative/osteogenic differentiation capacity of MSCs contained in local BMAC can be enhanced by minor corticotomies, and spontaneous healing of the corticotomy can be completed within 6 weeks of the operation.

Human gingiva-derived mesenchymal stem cells are therapeutic in lupus nephritis through targeting of CD39-CD73 signaling pathway.

Cell specific and cytokine targeted therapeutics have underperformed in systemic lupus erythematosus (SLE). Mesenchymal stem cells (MSCs) have emerged as a novel therapy to address the dysregulation in autoimmune diseases but also have limitations. Human gingiva derived MSCs (GMSCs) are superior in regulating immune responses. Here, we demonstrate that the adoptive transfer of GMSCs homes to and maintains in the kidney and has a robust therapeutic effect in a spontaneous lupus nephritis model. Specifically, GMSCs limits the development of autoantibodies as well as proteinuria, decreases the frequency of plasma cells and lupus nephritis histopathological scores by directly suppressing B cells activation, proliferation and differentiation. The blockage of CD39-CD73 pathway dramatically abrogates the suppressive capacities of GMSCs in vitro and in vivo and highlights the significance of this signaling pathway in SLE. Collectively, manipulation of GMSCs provides a promising strategy for the treatment of patients with SLE and other autoimmune diseases.

The Effect of Parathyroid Hormone Analogues When Added to Mineralized Bone Xenografts.

Implants can be a treatment option when there is sufficient quantity and quality of bone to provide support for long-term success. In the reconstruction of defects, autogenous bone remains the gold standard for its osteogenic and compatibility properties. However, the disadvantage of secondary surgery and the associated donor site morbidity prompts researchers to develop the ideal bone substitute for optimum bone reconstruction. Parathyroid hormone (PTH1-34) has provided a new option for improvement in bone regeneration. This study used a pig model to evaluate the effectiveness of parathyroid hormone when added to a xenograft, Bio-Oss, in reconstructing mandible defects. Six domestic pigs were used to create 3 posterior mandibular defects measuring 2 × 1-cm bilaterally with a total of 36 defects to simulate tooth extraction sites in humans. The defects were grafted in random order and divided into 3 groups as follows: control (no graft), Bio-Oss without PTH, and Bio-Oss with PTH. Defects were assessed with cone beam computerized tomography (CBCT), micro computerized tomography (microCT), nanoindentation, and histology. Results showed that adding PTH1-34 significantly enhanced the graft construct. CBCT showed a significant increase in the degree of bone mineralization. Nanoindentation showed increased hardness of regenerated bone and accelerated bone mineralization with PTH. MicroCT analysis revealed a trend toward higher bone regeneration and mineralization. The histological analysis showed a positive trend of the increase in cortical bone thickness and mineral apposition rate. In conclusion, the local addition of PTH1-34 to a xenograft has shown promising results to enhance bone regeneration in the reconstruction of mandibular defects.

Ludwig's Angina: Anesthetic Management.

Ludwig's angina (LA) is a gangrenous cellulitis of the neck that spreads via continuity of the fascial planes. Treatment of LA includes aggressive antibiotic therapy as well as surgical drainage in many cases. The most common cause of infection is odontogenic and can be due to both aerobic and anaerobic bacteria. Signs and symptoms of LA include bilateral cervical swelling, dysphagia, drooling, neck tenderness, elevation and posterior distension of the tongue, restricted neck movement, trismus, dyspnea, and stridor, which can result in difficult airway management. Proper preoperative assessment of patients with LA should include identifying features that may cause difficulties with mask ventilation, direct laryngoscopy, and intubation. Alternative methods of ventilation should be considered and immediately accessible, including a plan on how and when they would be used in the event that a patient cannot be mask ventilated or intubated. Marking external anatomical airway landmarks prior to manipulating the airway can save vital time if an emergent airway becomes necessary.

Malignant Hyperthermia: A Case Study in the Dental Ambulatory Surgery Setting.

Historically, patients who developed malignant hyperthermia had an extremely high rate of mortality. Today, if treated appropriately, patients who experience an episode of malignant hyperthermia will most likely survive. This dramatic decrease in mortality associated with malignant hyperthermia is due to several factors, including an increased understanding of the disease, improved diagnostic and monitoring equipment, and the development of lifesaving pharmacologic agents. This article presents the very likely case of acute malignant hyperthermia in a 24-year-old man with special needs, who presented for restorative dentistry under general anesthesia in the outpatient clinic of The Ohio State University's College of Dentistry.

Tube Decompression for Staged Treatment of a Calcifying Odontogenic Cyst-A Case Report.

The calcifying odontogenic cyst is a rare developmental odontogenic lesion with a distinguishing cystic lining containing "ghost" epithelial cells. The variation in clinical, radiographic, and histologic findings makes the treatment decision difficult for these lesions. There are very few reports on treatment, with enucleation and curettage being the standard surgical method of choice for the cystic type and excision of the tumor for the solid type. A 2-stage surgical approach consisting of initial decompression with tube placement followed by a secondary procedure of enucleation and curettage is common for other large odontogenic cysts, such as dentigerous and odontogenic keratocysts. To the authors' knowledge, this is the first case managed with an intended 2-stage approach in the form of decompression followed by enucleation and curettage.

Efficacy of Cone-Beam Computed Tomography in Evaluating Bone Quality for Optimum Implant Treatment Planning.

PURPOSE: This study examined (1) if cone-beam computed tomography (CBCT) can determine relative differences in bone mineral density distribution using clinical images of patients' mandibular bone and (2) if the relative differences can be used to detect the effects of sex and age on bone mineral density distribution. MATERIALS AND METHODS: Sixty-six clinical CBCT images from patients (36 females and 30 males) of 3 age groups (40, 50, and 60 years) were identified. Alveolar (AB) and basal cortical bone (CB) regions were digitally isolated. A histogram of gray levels, which are proportional to degrees of bone mineralization, was obtained from each region. Mean, variability (SD and coefficient of variation), and percentage differences of gray level parameters between AB and basal CBs were computed. RESULTS: Significant sex differences in gray level variability were observed within the postmenopausal age group (P < 0.042). CONCLUSION: These findings suggest that clinical CBCT images can be a valuable tool in providing information on bone quality, which is an important criterion for optimum planning for dental implant placement.

Similarities and differences between porcine mandibular and limb bone marrow mesenchymal stem cells.

OBJECTIVE: Research has shown promise of using bone marrow mesenchymal stem cells (BMSCs) for craniofacial bone regeneration; yet little is known about the differences of BMSCs from limb and craniofacial bones. This study compared pig mandibular and tibia BMSCs for their in vitro proliferation, osteogenic differentiation properties and gene expression. DESIGN: Bone marrow was aspirated from the tibia and mandible of 3-4 month-old pigs (n=4), followed by BMSC isolation, culture-expansion and characterization by flow cytometry. Proliferation rates were assessed using population doubling times. Osteogenic differentiation was evaluated by alkaline phosphatase activity. Affymetrix porcine microarray was used to compare gene expressions of tibial and mandibular BMSCs, followed by real-time RT-PCR evaluation of certain genes. RESULTS: Our results showed that BMSCs from both locations expressed MSC markers but not hematopoietic markers. The proliferation and osteogenic differentiation potential of mandibular BMSCs were significantly stronger than those of tibial BMSCs. Microarray analysis identified 404 highly abundant genes, out of which 334 genes were matched between the two locations and annotated into the same functional groups including osteogenesis and angiogenesis, while 70 genes were mismatched and annotated into different functional groups. In addition, 48 genes were differentially expressed by at least 1.5-fold difference between the two locations, including higher expression of cranial neural crest-related gene BMP-4 in mandibular BMSCs, which was confirmed by real-time RT-PCR. CONCLUSIONS: Altogether, these data indicate that despite strong similarities in gene expression between mandibular and tibial BMSCs, mandibular BMSCs express some genes differently than tibial BMSCs and have a phenotypic profile that may make them advantageous for craniofacial bone regeneration.

Lateral tarsotomy: a practical alternative to lateral canthotomy to increase orbital access.

OBJECTIVE: Transconjunctival approach to the lower one-third of the orbit is commonly used to avoid transcutaneous incisions when surgical access is needed. A lateral canthotomy is used in conjunction with this approach if increased lateral exposure is required. A major disadvantage to lateral canthotomy is difficulty in resuspension of the lateral canthal tendon, which can lead to unaesthetic outcomes. The present report describes two cases of lateral tarsal incision or, as we decided to call it, the "lateral tarsotomy" technique. This simple approach is used to increase lateral access to the orbit without the need for lateral canthotomy. STUDY DESIGN: Two patients presented with internal orbital wall trauma that required repair; access was achieved with a transconjunctival approach in conjunction with lateral tarsotomy. The patients were followed up at 1 week, 1 month, and 3 months to document the development of possible unaesthetic and poor functional outcomes. RESULTS: Excellent cosmetic results were observed, with no noticeable deformity at the tarsotomy site. There was no evidence of ectropion, entropion, scleral show, and visible scars. CONCLUSIONS: The above results suggest that the lateral tarsotomy approach is a practical alternative to lateral canthotomy when increased lateral exposure is required.

Applied surgical anatomy of the nose.

Although anatomy often seems static, the continual innovation of new surgical techniques and approaches, in reality, make it a dynamic field. The first essential principal of any surgery is the comprehensive knowledge of the anatomic area and its physiology. This assertion is especially true in functional and or cosmetic nasal surgery.

Difference in soft tissue response between immediate and delayed delivery suggests a new mechanism for recombinant human bone morphogenetic protein 2 action in large segmental bone defects.

The ability of recombinant human bone morphogenetic protein 2 on absorbable collagen sponge (rhBMP2/ACS) to regenerate bone in segmental defect has been well characterized. However, clinical results of rhBMP2/ACS constructs in secondary reconstruction of large mandibular and craniofacial defects have not been consistent. We hypothesized that rhBMP2 delivery triggers an endogenous response in the soft tissues surrounding the defect, in the form of expression of BMP2 and vascular endothelial growth factor (VEGF). Such osteogenic response will occur only after immediate, as opposed to delayed, rhBMP2 delivery, suggesting a new explanation to the difference in bone regeneration between the two settings. A 35-mm segmental bone and periosteum defect was created on one side of the mandible in 16 dogs divided in three groups. Group 1 (Gp1, n=6) ACS was loaded with 8 mL of rhBMP2 (0.2 mg/mL). In Gp2 (n=5) the same dose of rhBMP2/ACS was delivered into the defect 4 weeks after surgery. In Gp3 (control; n=5) the defect was reconstructed using ACS loaded with 8 mL of buffer only (devoid of rhBMP2). Tissues were collected after 12 weeks of reconstruction in all groups. Direct measurement of physical dimensions of regenerates and bone morphometry was performed to evaluate bone regeneration. The mRNA expression of both BMP2 and VEGF in the soft tissue surrounding the defect was evaluated using real-time quantitative PCR. Both BMP2 and VEGF proteins were quantified in immunostained sections. Immunoflurescence colocalization of BMP2 and acetylated low density lipoprotein (AcLDL) was done to detect the source of BMP2. Immediate delivery yielded better bone regeneration. Both BMP2 and VEGF mRNA expression was upregulated only in Gp1 (+7.3, p=0.001; +1.53, p=0.001, respectively). BMP2 protein was significantly higher in the immediate reconstruction group; however, VEGF protein was undetected in the examined sections. Immediate delivery of rhBMP2 seemed to induce endogenous release of BMP2 from the surrounding soft tissues, an effect that was lacking in delayed delivery and may explain the variability of clinical results associated with BMP2 use. Colocalization of BMP2 and endothelial cells (ECs) suggested that ECs could be the source of endogenous BMP2.

Can an arch bar replace a second lag screw in management of anterior mandibular fractures?

PURPOSE: To evaluate the efficacy of using a single lag screw combined with an arch bar in the management of anterior mandibular fractures and to compare this method with the traditional application of 2 lag screws. MATERIALS AND METHODS: We designed and implemented a randomized clinical trial and enrolled a sample of patients with anterior mandibular fractures. Twenty adult male patients were randomly divided into 2 equal groups according to the number of lag screws used for fracture fixation after securing the occlusion with intermaxillary fixation. In group A, the fractures were treated using 2 lag screws. In group B, the fractures were treated using a single lag screw and an arch bar on the teeth, spanning the fracture line. Clinical and radiographic evaluations were used to evaluate the efficacy of each fixation method immediately and at 2 and 4 months postoperatively. RESULTS: The clinical examination showed stable fixation with no mobility or infection in all cases. One patient in group A showed a slight occlusal discrepancy that was managed with occlusal adjustment. The pretraumatic occlusal relationship of all other patients was re-established. Postoperative radiographs showed properly reduced fracture segments with gradual bone healing. No significant difference was noted (P > .05) between the 2 groups in the development of postoperative complications. CONCLUSIONS: The use of 1 lag screw in conjunction with an arch bar across the fracture line is rigid and stable enough to manage anterior mandibular fractures without the need for supplemental intermaxillary fixation. The use of a single lag screw offers several advantages compared with the traditional use of 2 lag screws. These advantages include decreased cost, use of materials, healing time, and risk of associated morbidity.

Microcomputed tomographic and histologic analysis of anorganic bone matrix coupled with cell-binding peptide suspended in sodium hyaluronate carrier after sinus augmentation: a clinical study.

PURPOSE: Anorganic bovine hydroxyapatite matrix (ABM), when coupled with synthetic cell-binding peptide (P15), mimics the cell-binding region of type 1 collagen and is commercially available suspended in a sodium hyaluronate carrier. The aim of the present study, therefore, was to test the efficacy of ABM/P-15 Putty (DENTSPLY Friadent CeraMed) as a sole graft material for sinus augmentation in patients with severely resorbed posterior maxillae. MATERIALS AND METHODS: Sinus augmentation was performed in 10 patients using ABM/P-15 Putty and two provisional dental implants (3.0 mm in diameter). The graft and implants were placed simultaneously with the aid of a surgical stent. After 8 or 16 weeks, the implants were removed using a 4.25-mm trephine bur; this was followed by immediate placement of wider-diameter (5.5-mm) implants. All 20 implants were scanned by microcomputed tomography to determine bone mineral density (BMD), percent bone volume (PBV), and percent bone contact (PBC). RESULTS: There was a significant increase in the BMD of bone around the implants at 8 weeks and 16 weeks compared to native residual (control) bone. There was no significant difference in PBV or PBC between 8 weeks and 16 weeks. The average increase in bone height at 16 weeks was 9.63 ± 1 mm. Microcomputed tomographic images and histologic sections showed dense graft particles surrounded by vital trabecular bone. CONCLUSION: BMD increases as early as 8 weeks and does not show an additional increase after 16 weeks. PepGen P-15 Putty was found to be a promising osteoconductive graft for sinus augmentation, supporting immediate placement of implants.

Comparison of cellular response to anorganic bone matrix/cell binding peptide and allogenic cranial bone after sinus augmentation in rhesus monkeys.

This study compared cellular responses of maxillary sinuses after augmentation with anorganic bovine-derived hydroxyapatite matrix linked to the cell binding polypeptide P-15 (ABM/P-15) or PepGen P-15 and allogenic freeze-dried cranial bone slabs. Five adult Macaque fascicularis monkeys were used. On one side, the floor of the sinus was augmented with ABM/P-15, while the other side was augmented with 2 cranial bone slabs. Trephine bone biopsies were obtained 6, 12, and 24 weeks postgrafting. Animals were sacrificed 8 months after grafting. Soft X-ray microradiography was used to determine bone density. The volume fraction (Vv) of regenerated bone, the number of mesenchymal cells, and the numbers of proliferating cell nuclear antigen (PCNA)- and alkaline phosphatase-positive cells at different augmentation sites were measured and compared. Basal bone heights were calculated at surgery and compared with total heights of the augmented sinus floors 8 months postgrafting. Bone formation, number of mesenchymal cells, PCNA index, and alkaline phosphatase index were significantly higher for the ABM/P-15 side than for the allogenic bone-augmented side. Both sides ended with a significant increase in bone height. The PCNA index decreased significantly over time (P < .05), while the alkaline phosphatase index increased significantly (P < .05) over time on both sides. Both graft materials have led to significant augmentation of the floor of the maxillary sinus with new bone; however, new bone formation and maturation were faster on the ABM/P-15 sites.