Efficacy of treating segmental bone defects through endochondral ossification: 3D printed designs and bone metabolic activities.

Three-dimensional printing (3D printing) is a promising technique for producing scaffolds for bone tissue engineering applications. Porous scaffolds can be printed directly, and the design, shape and porosity can be controlled. 3D synthetic biodegradable polymeric scaffolds intended for in situ bone regeneration must meet stringent criteria, primarily appropriate mechanical properties, good 3D design, adequate biocompatibility and the ability to enhance bone formation. In this study, healing of critical-sized (5 â€‹mm) femur defects of rats was enhanced by implanting two different designs of 3D printed poly(l-lactide-co-ε-caprolactone) (poly(LA-co-CL)) scaffolds seeded with rat bone marrow mesenchymal stem cells (rBMSC), which had been pre-differentiated in vitro into cartilage-forming chondrocytes. Depending on the design, the scaffolds had an interconnected porous structure of 300-500 â€‹µm and porosity of 50-65%. According to a computational simulation, the internal force distribution was consistent with scaffold designs and comparable between the two designs. Moreover, the defects treated with 3D-printed scaffolds seeded with chondrocyte-like cells exhibited significantly increased bone formation up to 15 weeks compared with empty defects. In all experimental animals, bone metabolic activity was monitored by positron emission tomography 1, 3, 5, 7, 11 and 14 weeks after surgery. This demonstrated a time-dependent relationship between scaffold design and metabolic activity. This confirmed that successful regeneration was highly reproducible. The in vitro and in vivo data indicated that the experimental setups had promising outcomes and could facilitate new bone formation through endochondral ossification.

Corrigendum to "Health-Related Quality of Life and Sleep Quality after 12 Months of Treatment in Nonsevere Obstructive Sleep Apnea: A Randomized Clinical Trial with Continuous Positive Airway Pressure and Mandibular Advancement Splints".

[This corrects the article DOI: 10.1155/2020/2856460.].

Temporomandibular joint pain and associated magnetic resonance findings: a retrospective study with a control group.

BACKGROUND: To better understand and evaluate clinical usefulness of magnetic resonance imaging (MRI) in diagnosis and treatment of temporomandibular disorders (TMD), parameters for the evaluation are useful. PURPOSE: To assess a clinically suitable staging system for evaluation of MRI of the temporomandibular joint (TMJ) and correlate the findings with age and some clinical symptoms of the TMJ. MATERIAL AND METHODS: Retrospective analysis of 79 consecutive patients with clinical temporomandibular disorder or diagnosed inflammatory arthritis. Twenty-six healthy volunteers were included as controls. Existing data included TMJ pain, limited mouth opening (<30 mm) and corresponding MRI evaluations of the TMJs. RESULTS: The patients with clinical TMD complaints had statistically significantly more anterior disc displacement (ADD), disc deformation, caput flattening, surface destructions, osteophytes, and caput edema diagnosed by MRI compared to the controls. Among the arthritis patients, ADD, effusion, caput flattening, surface destructions, osteophytes, and caput edema were significantly more prevalent compared to the healthy volunteers. In the control group, disc deformation and presence of osteophytes significantly increased with age, and a borderline significance was found for ADD and surface destructions on the condylar head. No statistically significant associations were found between investigated clinical and MRI parameters. CONCLUSION: This study presents a clinically suitable staging system for comparable MRI findings in the TMJs. Our results indicate that some findings are due to age-related degenerative changes rather than pathological changes. Results also show that clinical findings such as pain and limited mouth opening may not be related to changes diagnosed by MRI.

Health-Related Quality of Life and Sleep Quality after 12 Months of Treatment in Nonsevere Obstructive Sleep Apnea: A Randomized Clinical Trial with Continuous Positive Airway Pressure and Mandibular Advancement Splints.

In this randomized controlled trial, patients with nonsevere obstructive sleep apnea (OSA) were treated with continuous positive airway pressure (CPAP) or a twin block mandibular advancement splint (MAS). The primary objective was to compare how CPAP and MAS treatments change the health-related quality of life (HRQoL) and self-reported sleep quality of patients after 12 months of treatment. In total, 104 patients were recruited: 55 were allocated to the CPAP treatment group and 49 to the MAS treatment group. We used the SF36 questionnaire to evaluate HRQoL and the Pittsburgh Sleep Quality Index (PSQI) to evaluate sleep quality. All patients were included in the intention-to-treat analyses. These analyses showed improvements in the SF36 physical component score (from 48.8 ± 7.6 at baseline to 50.5 ± 8.0 at follow-up, p=0.03) in the CPAP treatment group and in the mental component score (from 44.9 ± 12.1 to 49.3 ± 9.2, p=0.009) in the MAS treatment group. The PSQI global score improved in both the CPAP (from 7.7 ± 3.5 to 6.6 ± 2.9, p=0.006) and the MAS (8.0 ± 3.1 to 6.1 ± 2.6, p < 0.001) treatment groups. No difference was found between the treatment groups in any of the SF36 scores or PSQI global score at the final follow-up (p > 0.05) in any analysis. The improvement in the SF36 vitality domain moderately correlated to the improvement in the PSQI global score in both groups (CPAP: |r|=0.47, p < 0.001; MAS: |r|=0.36, p=0.01). In the MAS treatment group, we also found a weak correlation between improvements in the SF36 mental component score and PSQI global score (|r|=0.28, p=0.05). In conclusion, CPAP and MAS treatments lead to similar improvements in the HRQoL and self-reported sleep quality in nonsevere OSA. Improvements in aspects of HRQoL seem to be moderately correlated to the self-reported sleep quality in both CPAP and MAS treatments.

Friedman Score in Relation to Compliance and Treatment Response in Nonsevere Obstructive Sleep Apnea.

Nonsevere obstructive sleep apnea (OSA) is most often treated with a continuous positive airway pressure (CPAP) device or a mandibular advancement splint (MAS). However, patient compliance with these treatments is difficult to predict. Improvement in apnea-hypopnea index (AHI) is also somewhat unpredictable in MAS treatment. In this study, we investigated the association between Friedman tongue position score (Friedman score) and both treatment compliance and AHI improvement in patients with nonsevere OSA receiving CPAP or MAS treatment. 104 patients with nonsevere OSA were randomly allocated to CPAP or MAS treatment and followed for 12 months. Data were collected through a medical examination, questionnaires, sleep recordings from ambulatory type 3 polygraphic sleep recording devices, and CPAP recordings. Associations between Friedman score, treatment compliance, and AHI improvement were analysed with logistic regression analyses. Friedman score was not associated with treatment compliance (odds ratio [OR]: 0.85, 95% confidence interval [CI]: 0.59-1.23), or AHI improvement (OR: 1.05, 95% CI: 0.62-1.76) in the overall study sample, the CPAP treatment group, or the MAS treatment group. Adjustment for socioeconomic factors, body mass index, and tonsil size did not significantly impact the results. Although Friedman score may predict OSA severity and contribute to the prediction of success in uvulopalatopharyngoplasty, we found no association between Friedman score and treatment compliance in patients with nonsevere OSA receiving CPAP or MAS treatment, nor did we find any association between Friedman score and AHI improvement. Factors other than Friedman score should be considered when deciding whether a patient with nonsevere OSA should be treated with CPAP or MAS.

Translation of a standardized manufacturing protocol for mesenchymal stromal cells: A systematic comparison of validation and manufacturing data.

BACKGROUND: Many data are available on expansion protocols for mesenchymal stromal cells (MSCs) for both experimental settings and manufacturing for clinical trials. However, there is a lack of information on translation of established protocols for Good Manufacturing Practice (GMP) from validation to manufacturing for clinical application. We present the validation and translation of a standardized pre-clinical protocol for isolation and expansion of MSCs for a clinical trial for reconstitution of alveolar bone. METHODS: Key parameters of 22 large-scale expansions of MSCs from bone marrow (BM) for validation were compared with 11 expansions manufactured for the clinical trial "Jaw bone reconstruction using a combination of autologous mesenchymal stromal cells and biomaterial prior to dental implant placement (MAXILLO1)" aimed at reconstruction of alveolar bone. RESULTS: Despite variations of the starting material, the robust protocol led to stable performance characteristics of expanded MSCs. Manufacturing of the autologous advanced therapy medicinal product MAXILLO-1-MSC was possible, requiring 21 days for each product. Transport of BM aspirates and MSCs within 24 h was guaranteed. MSCs fulfilled quality criteria requested by the national competent authority. In one case, the delivered MSCs developed a mosaic in chromosomal finding, showing no abnormality in differentiation capacity, growth behavior or surface marker expression during long-term culture. The proportion of cells with the mosaic decreased in long-term culture and cells stopped growth after 38.4 population doublings. CONCLUSIONS: Clinical use of freshly prepared MSCs, manufactured according to a standardized and validated protocol, is feasible for bone regeneration, even if there was a long local distance between manufacturing center and clinical site. Several parameters, such as colony forming units fibroblasts (CFU-F), percentage of CD34+ cells, cell count of mononuclear cells (MNCs) and white blood cells (WBCs), of the BM may serve as a predictive tool for the yield of MSCs and may help to avoid unnecessary costs for MSC manufacturing due to insufficient cell expansion rates.

Cell therapy induced regeneration of severely atrophied mandibular bone in a clinical trial.

BACKGROUND: Autologous grafting, despite some disadvantages, is still considered the gold standard for reconstruction of maxillofacial bone defects. The aim of this study was to evaluate bone regeneration using bone marrow-derived mesenchymal stromal cells (MSCs) in a clinical trial, a less invasive approach than autologous bone grafting. This comprehensive clinical trial included subjects with severe mandibular ridge resorption. METHODS: The study included 11 subjects aged 52-79 years with severe mandibular ridge resorption. Bone marrow cells were aspirated from the posterior iliac crest and plastic adherent cells were expanded in culture medium containing human platelet lysate. The MSCs and biphasic calcium phosphate granules as scaffolds were inserted subperiosteally onto the resorbed alveolar ridge. After 4-6 months of healing, new bone formation was assessed clinically and radiographically, as were safety and feasibility. Bone at the implant site was biopsied for micro-computed topography and histological analyses and dental implants were placed in the newly regenerated bone. Functional outcomes and patient satisfaction were assessed after 12 months. RESULTS: The bone marrow cells, expanded in vitro and inserted into the defect together with biphasic calcium phosphate granules, induced significant new bone formation. The regenerated bone volume was adequate for dental implant installation. Healing was uneventful, without adverse events. The patients were satisfied with the esthetic and functional outcomes. No side effects were observed. CONCLUSIONS: The results of this comprehensive clinical trial in human subjects confirm that MSCs can successfully induce significant formation of new bone, with no untoward sequelae. Hence, this novel augmentation procedure warrants further investigation and may form the basis of a valid treatment protocol, challenging the current gold standard. TRIAL REGISTRATION: EudraCT, 2012-003139-50. Registered on 21 August 2013. ClinicalTrials.gov, NCT 02751125 . Registered on 26 April 2016.

Comparison of short-run cell seeding methods for poly(L-lactide-co-1,5-dioxepan-2-one) scaffold intended for bone tissue engineering.

Constructs intended for bone tissue engineering are influenced by the initial cell seeding procedure. The seeding method should be rapid, convenient, improve cell spatial distribution, and have no negative effects on cellular viability and differentiation. This study aimed to compare the effect of short-run seeding methods (centrifuge and vortex) with a static method on the scaffolds prepared from poly(L-lactide-co-1,5-dioxepan-2-one) by solvent-casting particulate-leaching (SCPL) technique. Human osteoblast-like cells (HOB) were seeded by the three methods described above. The seeding efficiency was determined by attached cell numbers. Cellular proliferation was analyzed by WST-1 and dsDNA assay. Cell distribution was examined by scanning electron (SEM) and fluorescence microscopy. Expression of alkaline phosphatase (ALP), collagen type I (Col I), osteocalcin (OC) and proliferating cell nuclear antigen (PCNA) were determined by real time RT-PCR. Results indicated that centrifuge and vortex increased seeding efficiency and had no negative effects on cellular viability. The data obtained by the fluorescence microscope confirmed the SEM results that the vortex method improved cell distribution through the scaffolds more than the other two methods (p<0.05). The RT-PCR results showed no significant differences on the expression of mRNA between the three methods of the above markers. The vortex method was found to be a simple and feasible seeding method for the poly(L-lactide-co-1,5-dioxepan-2-one) scaffolds.

Effect of endothelial cells on bone regeneration using poly(L-lactide-co-1,5-dioxepan-2-one) scaffolds.

Our recent in vitro study demonstrated that endothelial cells (ECs) might influence the differentiation of bone marrow stromal cells (BMSCs). Therefore, the aim of this study was to describe this effect in vivo, using a rat calvarial bone defect model. BMSCs were isolated from femurs of two-donor Lewis rats and expanded in α-minimum essential medium containing 10% fetal bovine serum. One fifth of BMSCs were induced and differentiated into ECs in an Endothelial Cell Growth Medium-2 and then characterized by a flow cytometry. The remaining BMSCs were cultured in freshly prepared osteogenic stimulatory medium, containing dexamethasone, ascorbic acid and ß-glycerophosphate. Either BMSCs alone (BMSC-group) or co-cultured ECs/BMSCs (CO-group) were seeded into poly(L-lactide-co-1,5-dioxepan-2-one) [poly(LLA-co-DXO)] scaffolds, cultured in spinner flasks, and then implanted into symmetrical calvarial defects prepared in recipient rats. The animals were sacrificed after 2 months. The formation of new bone was evaluated by radiography and histology and by the expression of osteogenic markers using reverse transcriptase-polymerized chain reaction (RT-PCR). To investigate vessel formation, histological staining was performed with EC's markers. The radiographical and histological results showed more rapid bone formation in the CO- than in the BMSC-group. However, the expression of EC's marker was similar on both groups by histological analysis after 2 months postoperatively. Furthermore, the CO-group exhibited greater expression of osteogenic markers as demonstrated by RT-PCR. The results are consistent with the previous in vitro findings that poly(LLA-co-DXO) scaffold might be suitable candidate for bone tissue engineering. In vivo, bone regeneration was enhanced by a construct of the polymer scaffold loaded with co-cultured cells.

Growth and differentiation of bone marrow stromal cells on biodegradable polymer scaffolds: an in vitro study.

A fundamental component of bone tissue engineering is an appropriate scaffold as a carrier for osteogenic cells. The aim of the study was to evaluate the response of human bone marrow stromal cells (BMSC) to scaffolds made of three biodegradable polymers: poly(L-lactide-co-ε-caprolactone) (poly(LLA-co-CL)), poly(L-lactide-co-1,5dioxepan-2-one) (poly(LLA-co-DXO)), and poly(L-lactide) (poly(LLA)). Cellular response was evaluated in terms of attachment, proliferation, and differentiation. SEM disclosed earlier cell attachment and better spreading on poly(LLA-co-CL) and poly(LLA-co-DXO) scaffolds than on poly(LLA) after 1 h. At 24 h and 14 days postseeding, BMSCs had spread well, forming multiple cellular layers on the scaffolds. Cell proliferation was higher on poly(LLA-co-CL) and on poly(LLA-co-DXO) than on poly(LLA) after 1 and 7 days. Cell growth cycles of BMSC were longer on the scaffolds than on coverslips. After 7 and 14 days cultivation on scaffolds, the expression of osteogenic markers such as ALP, Col I, OPN, and Runx2 were stimulated by BMSC, which indicating that poly(LLA-co-DXO), poly(LLA-co-CL), and poly(LLA) could support the osteogenic differentiation of BMSC in vitro. Poly(LLA-co-CL) and poly(LLA-co-DXO) promoted better attachment and growth of BMSC than poly(LLA). BMSC also retained their osteogenic differentiation potential, indicating biological activity of BMSC on the scaffolds. The promising results of this in vitro study indicate that these copolymers warrant further evaluation for potential application in bone tissue engineering.

A practical approach to interpretation of MRI of the temporomandibular joint.

BACKGROUND: Temporomandibular disorders (TMDs) such as pain, joint sounds, and impaired movement are common, and magnetic resonance imaging (MRI) is now the method of choice for diagnostic assessment. PURPOSE: To describe MR criteria chosen and the amount of temporomandibular joint (TMJ) pathology registered when examining MR images from patients referred to a university hospital for imaging of their TMJs. MATERIAL AND METHODS: The TMJs of 152 consecutive patients, 102 women and 40 men, referred for MRI during an 18 month period were imaged with a 1.5 T imaging system. Twelve asymptomatic students, seven women and five men, gave informed consent and acted as a control group. RESULTS: Moderate to extensive disk displacement was registered in 53% of the patients' TMJs, and 38% of the disks were deformed. Degenerative changes registered were flattening of the condyle heads in 50% of the TMJs and erosion of their cortical surfaces in 30%. Osteophytes were present in 31% of the condyles and bone marrow edema in 30%. Marked to extensive effusion in synovial compartments was registered in 39% of the studied TMJs. In the control group, none of the TMJs showed anterior disk displacement, deformed disks or degenerative changes, but 8 of the 24 joints showed marked effusion. A tendency for a higher amount of disk displacement and deformation was seen among young age groups and more degenerative changes in older age groups, but differences among groups were not significant when tested with chi-square analysis. CONCLUSION: Defined MR criteria that allow for comparative assessment are presented. According to these criteria, a large proportion of the patients referred for MR examination showed morphologic changes indicating TMJ pathology.

Endothelial cells influence the osteogenic potential of bone marrow stromal cells.

BACKGROUND: Improved understanding of the interactions between bone cells and endothelial cells involved in osteogenesis should aid the development of new strategies for bone tissue engineering. The aim of the present study was to determine whether direct communication between bone marrow stromal cells (MSC) and human umbilical vein endothelial cells (EC) could influence the osteogenic potential of MSC in osteogenic factor-free medium. METHODS: After adding EC to MSC in a direct-contact system, cell viability and morphology were investigated with the WST assay and immunostaining. The effects on osteogenic differentiation of adding EC to MSC was systematically tested by the using Superarray assay and results were confirmed with real-time PCR. RESULTS: Five days after the addition of EC to MSC in a ratio of 1:5 (EC/MSC) significant increases in cell proliferation and cellular bridges between the two cell types were detected, as well as increased mRNA expression of alkaline phosphatase (ALP). This effect was greater than that seen with addition of osteogenic factors such as dexamethasone, ascorbic acid and beta-glycerophosphate to the culture medium. The expression of transcription factor Runx2 was enhanced in MSC incubated with osteogenic stimulatory medium, but was not influenced by induction with EC. The expression of Collagen type I was not influenced by EC but the cells grown in the osteogenic factor-free medium exhibited higher expression than those cultured with osteogenic stimulatory medium. CONCLUSION: These results show that co-culturing of EC and MSC for 5 days influences osteogenic differentiation of MSC, an effect that might be independent of Runx2, and enhances the production of ALP by MSC.

The long-term effect of anti TNF-alpha treatment on temporomandibular joints, oral mucosa, and salivary flow in patients with active rheumatoid arthritis: a pilot study.

OBJECTIVE: The objective of this study was to evaluate the long-term effects of anti-TNF-alpha treatment on temporomandibular joints (TMJs), oral mucosa, and salivary flow in RA. STUDY DESIGN: Seventeen patients received infusions of TNF-alpha blocking agents after 0, 2, and 6 weeks, and then every 8 weeks until week 54 (follow-up). Clinical dysfunction index (Di) for the TMJ system, salivary flow, disease activity score (DAS28), and other medical assessments were calculated at weeks 0 and 54. RESULTS: Median Di was 5.0 (range 0-21) at baseline and 1.0 (range 0-6) (P = .001) at follow-up. Mean salivary flow was 3.2 mL/15 minutes at baseline and 4.6 at follow-up (P = .055). Two (11.7%) of the patients developed oral candidiasis during the period of treatment. The median DAS28 was 6.2 (range, 4.7-7.7) at baseline and 4.1 (range, 1.6-6.8) at follow-up (P = .001). CONCLUSION: We conclude that anti-TNF-alpha blocking treatments have beneficial effects on oral as well as general manifestations of RA.

Displaced calcium hydroxide paste causing inferior alveolar nerve paraesthesia: report of a case.

A patient presented with an intraoral red, painful, and hard swelling in the lower right jaw. Radiographs showed a 2 x 1 cm area of radiopaque material surrounding the apex of the second premolar. The material, according to the patient's dentist, was calcium hydroxide paste used as a temporary dressing material in the root canal. The patient developed paraesthesia in her lower lip probably due to a neurotoxic effect caused by calcium hydroxide. The foreign material was surgically excavated from the spongious bone, directly adjacent to the nerve, and the patient later regained her sensation in the lip. A histopathological analysis revealed necrosis, deposits of foreign bodies, and inflammatory cells and foreign-body giant cells. This report illustrates the toxicity and adjacent clinical symptoms of calcium hydroxide paste when displaced into bone tissue close to the alveolar inferior nerve. It also demonstrates the benefits of removing such displaced material before symptoms progress.

Implant treatment in combination with lateral augmentation of the alveolar process: a 3-year prospective study.

BACKGROUND: In patients in whom the height of the alveolar process is adequate but the crest is too narrow to host an implant, lateral augmentation is required. Such augmentations have mostly been performed using autogenous bone blocks secured to the buccal surface. An alternative to autogenous bone may be bovine hydroxyapatite (Bio-Oss, Geistlich Pharma AG, Wolhusen, Switzerland) or other bone substitutes. PURPOSE: The aim of this study was to evaluate the clinical and radiographic outcome of dental implants inserted after lateral augmentation of too narrow alveolar processes with a combination of bovine hydroxyapatite (Bio-Oss) and autogenous bone. METHODS: Thirty patients (14 males and 16 females) with a mean age of 41.6 years fulfilled the inclusion criteria. Twenty-nine augmentation sites with a total of 74 implants could be followed for 3 years. RESULTS: Three implants were lost; these were lost before loading (at the abutment operation). The survival rate was 95.9%. The mean marginal bone loss during the 3-year observation period was 0.3 +/- 0.2 mm. CONCLUSIONS: A 50/50 combination of Bio-Oss and autogenous bone chips stabilized with Tisseel (Baxter AG/Duo Quick AG, Vienna, Austria) was useful for lateral augmentation of the alveolar crest. Lateral grafts with Bio-Oss, autogenous bone, and Tisseel made it possible to achieve good implant stability and high implant survival results. The bone level changes adjacent to the implants were the same as in nongrafted cases.