Aim: In a human pilot case, we used a root formed temporary prosthetical device (Intra-alveolar Device - IAD), to investigate the effect of mechanical stimulation on hard tissue clinically and radiographically. Background: The extraction of a tooth determines the resorption of the alveolar bone. This determines challenge to place an implant and to integrate the prosthesis in soft tissue. Mechanical stimulation is fundamental for bone tropism but is not understood the effect of mechanical stimulation on post-extraction site. Case presentation: A 24 years old woman was enrolled. The IAD’s were used as expected by protocol. Clinical healing was uneventfully. Vertical radiographical bone resorption measured on CBCT was -0,14mm (5,6%) while horizontal bone resorption was -0,21mm (12,36%). Conclusion: This study demonstrated the feasibility of the proposed model. We need clinical prospectical studies enrolling more patients

(1) Background: Proximal humerus fractures can be a debilitating condition if not properly treated. These fracture patterns are varied and differ in every patient. Functional outcomes may be determined by the integrity of the shoulder girdle involving the rotator cuff insertion. The post-operative resorption or malreduction of the greater tuberosity is an important factor contributing to the poor functional outcome of a patient. (2) Methods: A single-center retrospective comparative study was performed to evaluate the functional outcomes of patients undergoing operative fixation for this injury. A total of 387 consecutive cases treated operatively from 2019-2021 were included for analysis. (3) Results: 94 cases fulfilled our criteria for analysis. A matched-group comparison of 19 patients each was performed to compare demographics, post-operative fracture characteristics and functional outcomes. (4) Conclusions: The resorption or malreduction of the greater tuberosity contributes greatly to the prognostic outcome in patients treated with ORIF surgery. In our demographic study, obesity is another contributing factor affecting the parameters of post-operative reduction in proximal humerus fractures. Appropriate surgical planning and post-operative multidisciplinary care must be taken into consideration to attain a satisfactory prognostic outcome.

: Background: Cartilage harvest and transplantation is a common surgery using costal, auricular, and septal cartilage for craniofacial reconstruction. However, absorption and warping of the cartilage grafts can occur due to inflammatory factors associated with wound healing. Transcriptional factor nuclear factor κB (NFκB) is activated by cytokines, such as interleukin-1 (IL-1), and plays a central role in the transactivation of this inflammatory cytokine gene. Inhibition of NFκB may have anti-inflammatory effects. The aim of this study was to explore the potential of an NFκB decoy oligodeoxynucleotide (Decoy) as a chondroprotective agent. Materials and Methods: Evaluation of safe and efficacious concentrations of Decoy were assessed using rabbit nasal septal chondrocytes (rNSCh) and assays for cytotoxicity, proteoglycan (PG) synthesis, and PG turnover. The efficacious concentration of Decoy determined from the rNSCh was then applied to human nasal septal cartilage (hNSC) in vitro and analyzed for PG turnover, the level of inflammatory markers, and catabolic enzymes in explant-conditioned culture medium. Results: Over the range of Decoy conditions and concentrations, no inhibition of PG synthesis or cytotoxicity was observed. Decoy at 10 μM effectively inhibited PG degradation in the hNSC explant, prolonging PG half-life 63% and decreasing matrix metalloprotease 3 (MMP3) by 70.7% (P = 0.027). Conclusions: Decoy may be a novel chondroprotective therapeutic agent in cartilage transplantation due to its ability to inhibit cartilage degradation due to inflammation cytokines.

AbstractCadaver bone is possibly the most common transplant material used today. Common types of cadaver bone transplants are freeze-dried bone allografts and xenografts. Studies have shown that mineralized freeze-dried bone allografts have the same percentage of retained bone graft particles at different time points, indicating that these materials are never resorbed. However, it is commonly accepted by clinicians that these materials are resorbed and convert the graft site into normal bone. This histologic study was undertaken to determine the fate of mineralized freeze-dried bone allograft particles grafted into human extraction sockets. Materials and Methods:This study is a photographic, radiologic, and histological analysis of mineralized freeze-dried bone allograft healing in human sockets after mineralization at different time points. The mineralized freeze-dried bone allografts used for evaluation in this study were particulate bone graft materials in maxillary or mandibular extraction sockets. Patient selection was random, based on the following time periods: 6 months, 2 years, 5 years, 7 years, 10 years and 15 years. No block bone grafts were evaluated. Results:No resorption of cadaver bone graft particles was found at any time point. No osteoclasts were found in any of the histology at any time point. At different time points from 6 months through 15 years, mineralized freeze-dried bone allograft particles were found to be exfoliated out of the alveolar crest as a result of the formation of a hypervascular zone surrounding the grafted site. The embedded graft particles remain embedded in sclerotic bone until the particles reach the alveolar crest at which time the sclerotic bone and graft particles break up and are released into the gingiva. All histologic samples from 6 months to 15 years contained residual graft particles. The sclerotic bone formed around graft particles did not integrate to the graft particles or the implant surface. Conclusions:Mineralized freeze-dried bone allograft particles are not resorbed after mineralization. A hypervascular zone forms around the grafted site and exfoliates the bone graft particles into the gingiva. The mineralization process produces sclerotic bone which never remodels into normal bone. Sclerotic bone covers but does not integrate to the retained bone graft particles or implant surface resulting in a weakened structure with an increased likelihood of bone failure and implant loss.

A recent study reported that micro-osteoperforations (MOPs) accelerated tooth movement by activating alveolar bone remodeling. However, very little is known about the relationship between MOPs and external apical root resorption during orthodontic treatment. In this study, in order to investigate the mechanism which MOPs accelerate tooth movement without exacerbating the progression of root resorption, we measured the volume of resorbed root, and performed the immunostaining for the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end-labelling method (TUNEL) exposed MOPs during rat experimental tooth movement. Male Wistar rats (11 week old) were divided into 3 groups: 10-g orthodontic force (optimal force) applied to the maxillary first molar (optimal force: OF group), 50-g orthodontic force application (heavy force: HF group) and 10-g force application plus 3 small perforations of the cortical plate (OF+MOPs group). On days 1, 4, 7, 10 and 14 after force application, the tooth movement and root volume were investigated by micro-computed tomography. Furthermore, the expression levels of apoptotic cells in pressure sides of periodontal ligament (PDL) and surround hard tissues were determined by TUNEL staining. The OF+MOP group exhibited a 1.8-fold increase in tooth movement on days 7, 10 and 14 compared with the OF group. On days 14, the HF group had a higher volume of root loss than the OF and OF+MOP groups. On the same day, the number of TUNEL-positive cells in the HF group increased at the root (cementum) site whereas that in the OF group increased at the alveolar bone site. Furthermore, that in the OF + MOP group increased at the alveolar bone site compared with the OF group. These results suggest that MOPs accelerate orthodontic tooth movement without exacerbating the progression of root resorption.

Our results demonstrated that SWT stimulates osteoblastogenesis and increase the cell number of osteoblasts, suggesting positive regulatory effects on osteoblast differentiation. However, the effect of SWT on bone formation need further examination, since the expression of alp gene is downregulated. On the other hand, SWT appears to negatively regulate osteoclast differentiation and bone resorption, as number of osteoclasts and the expression of critical bone resorptive genes are all downregulated. Collectively, SWT might change the equilibrium of bone remodeling and increase the bone mass. Our data provided supportive evidences that this medicine formulation can be applied to treat osteoporosis or bone destructive diseases.

(1)Background: The prognosis of orthodontic treatment for a patient with impacted canine teeth can be affected by many factors and understanding some of the characteristics of impacted teeth can increase the effectiveness and reduce the duration of treatment. This study aims to explore the effects of positions and dentoalveolar morphological characteristics of impacted maxillary canines on the prognosis of orthodontic treatment. (2)Methods: In this study, a total of 46 adolescent individuals were divided into 3 groups: CC(no impaction), BC(unilateral maxillary buccal canine impaction), and PC(unilateral maxillary palatal canine impaction). The impacted canine and adjacent teeth were evaluated in terms of position, angulation, inclination, MD and BL widths, root length, dilaceration angle, root resorption. (3)Results: The mean values of U3Ang and U3/U2 angles were statistically significantly higher in the BC and PC groups(p<0.001). The mean values of U2RL(U3root length) and U3RD (U3root dilaceration) angle were statistically significantly lower in the BC and PC groups. (4)Conclusions: The results of this study suggest that shorter lengths and reduced volumes of the maxillary lateral incisors may lead to the ectopic eruption of canines. The higher canine angulations in the PC group make treatment more difficult and increase the degree of root resorption.

The present study was performed to examine that transforming growth factor beta (TGF-β) in root-surrounding tissues on deciduous teeth during the physiological root resorption regulates the differentiation induction into odontoclast. We prepared root-surrounding tissues with (R) or without (N) physiological root resorption scraped off at three regions (R1-R3 or N1-N3) from the cervical area to the apical area of the tooth and measured both TGF-β and the tartrate-resistant acid phosphatase (TRAP) activities. The TGF-β activity level was increased in N1-N3, whereas the TRAP activity was increased in R2 and R3. In vitro experiments for RANKL-mediated osteoclast differentiation revealed that TGF-β in N1-N3 and R1-R3 enhanced the TRAP activity in RAW264 cells. A genetic study indicated that the mRNA level of TGF-β1 in N1 and N2 was significantly increased, and corresponded with that of osteoprotegerin (OPG). In contrast, the expression level of receptor activator of NF-κB ligand (RANKL) was increased in R2 and R3. Our findings suggest that TGF-β is closely related to the regulation of OPG induction and RANKL-mediated odontoclast differentiation depending on the timing of RANKL and OPG mRNA expression in the root-surrounding tissues of deciduous teeth during physiological root resorption.

The orthodontic treatment brings numerous benefits and, in most cases, the benefits outweigh the possible disadvantages. Root resorption (RR) is a common adverse phenomenon associated with orthodontic treatment. This study evaluates the role of low-level laser emission / Photobiomodu-lation (LE/P) in quantitative measurements of root resorption (QRR). The application of LE/P was done after each orthodontic activation with 4 types of treatment intervention (TI) on the RR after fixed orthodontic treatment (FOT) of the upper arch with ectopic eye tooth/teeth [EET]. 32 Orthodontic patients scheduled for FOT were selected and assigned to the 4 groups. These were LE/P+Self ligating bracket (SLB), LE/P+Conventional bracket (CB), Non-Photobiomodulation (non-LE/P)+SLB, and non-LE/P+CB. Standard management stages of FOT were followed in the maxilla. Each patient received a single application of LE/P labially/buccally and palatally, a total of 5 different points during each activation or appointment. The main outcome measure was QRR in maxillary anteriors before and after FOT assessed via cone-beam computed tomography (CBCT) using 3D OnDemand software. Insignificant QRR was found between before and after FOT in SLB, CLB, and LE/P, non-LE/P groups (p > 0.05). QRR in the SLB vs CB and LE/P vs non-LE/P group was significantly different in 11, 13, and 23 (p < 0.05). QRR in the LE/P+SLB group (p < 0.05) was significantly different in 11, 13, and 23 than that in the other groups. The most severe QRR was found on the 13 (0.88 ± 0.28mm and 0.87±0.27mm) and 23 (1.19 ± 0.14 mm and 1.16±0.13mm) in the CB and non-LE/P group (p < 0.001). LE/P+SLB showed highly significant superior outcome (p < 0.001) in relation to non-LE/P+CB, the QRR of 23 were 0.813± 0.114mm and 1.156± 0.166mm respectively. Significantly higher amount of QRR found in EET patients after FOT treated with the CB, non-LE/P, and non-LE/P+CB system and warrants further investigation to explore potential specific causes.

Butyric acid as a histone deacetylase (HDAC) inhibitor was produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on matrix and mineralization markers’ expression of MG-63 osteoblasts. Cell viability and proliferation were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/Annexin V flow cytometry. Protein and mRNA expression of OPG, and RANKL were analyzed by western blotting and RT-PCR. OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, MMP-2, osteonectin (SPARC), osteocalcin and osteopontin secretion into culture medium were measured by enzyme-linked immunosorbant assay. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and western blot. We found that butyrate induced morphologic changes of growing MG-63 cells, with bigger and flattened in appearance. Butyrate activated histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell number with no marked increase in apoptosis and necrosis. Butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas sRANKL level was below detection limit. Butyrate stimulated 8-isoprostane, MMP-2 and osteopontin secretion, but not procollagen I, osteonectin, osteocalcin in MG-63 cells. In conclusion, butyric acid generated by periodontal and root canal microorganisms may potentially induce bony destruction and impair bone repair by alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2, and osteopontin secretion, and affect cell proliferation. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis of periodontal and periapical destruction.

Some studies have demonstrated that in vivo degradation processes are influenced by the material’s physico-chemical properties. The present study compares two hydroxyapatites manufactured on an industrial scale, deproteinized at low and high temperatures, and how physico-chemical properties can influence the mineral degradation process of material performance in bone biopsies retrieved 6 months after maxillary sinus augmentation. Residual biomaterial particles were examined by field scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) to determine the composition and degree of degradation of the bone graft substitute material. According to the EDX analysis, the Ca/P ratio significantly lowered in the residual biomaterial (1.08±0.32) compared to the initial composition (2.22±0.08) for the low-temperature sintered group, which also presented high porosity, low crystallinity, low density, a large surface area, and poor stability and a high resorption rate compared to the high-temperature sintered material. This demonstrates that variations in the physico-chemical properties of bone substitute material clearly influence the degradation process. Further studies are needed to determine whether the resorption of deproteinized bone particles proceeds slowly enough to allow sufficient time for bone maturation to occur.