Comparative Study of 660 and 830 nm Photobiomodulation in Promoting Orthodontic Tooth Movement.

Objective: Photobiomodulation (PBM) can usefully promote wound healing and relieve pain via its biological effects, with a wide range of applications in clinical medicine. The aim of the present study was to investigate the effect of 660 and 830 nm PBM on orthodontic tooth movement. Background data: PBM is based on the biological effects of diode laser irradiation on tissues, promoting cell proliferation and activity. Materials and methods: An orthodontic force was applied to the upper right first molars exposed to a 660 and 830 nm PBM (LHH-500I; Beijing Long Hui Heng Medical Science and Technology Development Corporation) on days 0, 1, 2, 3, 4, 5, and 7 for 50 sec with power density of 0.1 W/cm2 (a beam area of 0.5 cm2, radiate power of 0.05 W), energy density of 5 J/cm2 within 14 days, and a control group with no laser irradiation. Tooth movement was analyzed using a stereomicroscope, the number of osteoclasts determined by tartrate-resistant acid phosphatase (TRAP), and the expression of bone remodeling factors evaluated by immunohistochemistry. Results: The expression of IL-1ß, RANKL, and OPG was significantly stimulated in the 660 and 830 nm groups. The expression of RANKL was significantly higher in the 660 nm group than in the 830 nm group on days 5 and 7; however, there was no significant difference in the expression of OPG and IL-1ß between the 660 and 830 nm groups on days 1, 2, 3, 4, 5, 7, and 14. On days 3 and 5, the number of osteoclasts in the 660 nm group was higher than that in the 830 nm group, and the difference was statistically significant. Tooth movement over 14 days was significantly higher in the 660 and 830 nm groups than in the control group, and there was no significant difference between the 660 and 830 nm groups finally. Conclusions: Both 660 and 830 nm can accelerate the orthodontic tooth movement and promote alveolar bone remodeling on the compression side. Although the difference of tooth movement over 14 days between the two groups was not statistically significant; however, 660 nm PBM to accelerate bone remodeling is stronger than 830 nm PBM at an early stage.

Photobiomodulation increases intrusion tooth movement and modulates IL-6, IL-8 and IL-1ß expression during orthodontically bone remodeling.

This study investigated the effects of photobiomodulation (PBM) on upper molar intrusion movement, regarding acceleration of orthodontic movement and its molecular effects. The sample consisted of 30 patients with indication of tooth intrusion for oral rehabilitation. Teeth were divided into three different groups: G1 (n = 10) pre-molars without force or laser application (control); G2 (n = 10) upper molar intrusion; and G3 (n = 10) upper molar intrusion and PBM. On PBM treated molars, the teeth were irradiated with a low-power diode laser (808 nm, 100 mW), receiving 1 J per point, density of 25 J/cm2 , with application of 10 s per point, 10 points (5 per vestibular and 5 per palatal region). Orthodontic force of intrusion applied every 30 days and PBM was performed immediately, 3 and 7 days after force application for 3 months. Gingival crevicular fluid was collected at the same time periods as the laser applications and interleukins (IL) 1-ß, -6 and -8 were evaluated by enzyme-linked immunosorbent assay. Clinical measures were performed monthly to verify the amount of intrusion. The levels of IL-6, IL-8 and IL-1ß increased under orthodontic force (G2 and G3) when compared to control group (G1), however, the cytokines levels were significantly higher after PBM (G3). The mean intrusion velocity was 0.26 mm/month in the irradiated group (G3), average duration of 8 months vs 0.17 mm/month for the non-irradiated group (G2), average duration of 12 months. This study suggests that PBM accelerates tooth movement during molar intrusion, due to modulation of IL-6, IL-8 and IL-1ß during bone remodeling.

Hereditary component of variation in 90Sr deposition in inbred mice under exogenous conditions that affect bone formation.

Bone-seeking radionuclides (specifically 90Sr) accumulate in the bone tissue and act as a long-term source of internal irradiation. Their behaviour in the body has been studied in detail, while the impact of inheritance has not been established. On one hand, the genetic determination of both skeletal morphology and calcium metabolism is indirect evidence that the kinetics of deposition of alkaline-earth radioisotopes in the skeleton also have a hereditary component. On the other hand, analysis of 90Sr kinetics in different inbred mouse strains did not reveal any differences between the mice. This study used a classical approach to evaluating the hereditary component of variation in quantitative traits, namely, a variant of familial analysis (the method of twin families). The growth of the skeleton is known to be accompanied by distinct changes in 90Sr accumulation. That is why the hereditary (familial) component of variation in 90Sr kinetics in the bone tissue of CBA mice was analyzed under the influences that modify growth processes Individual parameters of 90Sr accumulation differed between experimental groups by a factor of 2-4.5. At the same time, features of 90Sr accumulation proved to be characteristic of entire families. The results show that the intrafamilial correlation in 90Sr deposition in the skeleton is highly significant (R = 0.542, P ≤ 0.0001) and comparable to that of morphological parameters (R = 0.532-0.546, P ≤ 0.0001). The results confirm the existence of statistically significant intrafamilial correlations of weight and metabolic parameters, which is similarly expressed in different families, thereby providing evidence for hereditary determination of 90Sr metabolism. At the same time, the stability of 90Sr metabolism inheritance to changes in morphophysiology and environmental influences (including those close to pathogenic ones) is shown. This is evidence of its authenticity and significance. The results obtained can be extrapolated to humans instead of directly analyzing the role of hereditary factors in the metabolism of toxic compounds, which are difficult and unethical to perform in human subjects.

Alveolar bone remodeling after tooth extraction in irradiated mandible: An experimental study with canine model.

OBJECTIVES: The aim of the present study is to investigate the morphological and cellular changes in dental extraction socket that has been irradiated after the tooth extraction and to describe morphological characteristics of the osteocytes and osteocyte-lacunar-canalicular network (LCN) by scanning electron microscopy (SEM). MATERIAL AND METHODS: Five beagle dogs aged 1-2 years were used in this study. One side of each mandible was irradiated in two sessions and the other side of mandible (non-irradiated) served as a control. The mandible bone blocks were processed by bulk staining en bloc in basic fuchsin and the specimens were embedded routinely in polymethyl methacrylate resin without preliminary decalcification. All blocks were subjected to micro-CT imaging, after that the specimens were prepared for light microscopy and SEM. RESULTS: Alterations in bone macrostructure are minimal in irradiated bone, but the changes in LCN are clear. In the area of the tooth extraction socket, the connections of osteocytes to the vessels and to neighboring osteocytes were not observed both in irradiated and nonirradiated bone. However, osteoclasts were located in the bone surface entering inside to the bone between osteons. In the lamellar bone of lateral sides, a decrease in canalicular connections between osteocytes and periosteum was found in irradiated bone as compared to the non-irradiated side. CONCLUSIONS: The novelty of the present study is that radiation disrupts osteocytes and their dendrites.

Therapeutic ionizing radiation induced bone loss: a review of in vivo and in vitro findings.

Radiation therapy is one of the routine treatment modalities for cancer patients. Ionizing radiation (IR) can induce bone loss, and consequently increases the risk of fractures with delayed and nonunion of the bone in the cancer patients who receive radiotherapy. The orchestrated bone remodeling can be disrupted due to the affected behaviors of bone cells, including bone mesenchymal stem cells (BMSCs), osteoblasts and osteoclasts. BMSCs and osteoblasts are relatively radioresistant compared with osteoclasts and its progenitors. Owing to different radiosensitivities of bone cells, unbalanced bone remodeling caused by IR is closely associated with the dose absorbed. For doses less than 2 Gy, osteoclastogenesis and adipogenesis by BMSCs are enhanced, while there are limited effects on osteoblasts. High doses (>10 Gy) induce disrupted architecture of bone, which is usually related to decreased osteogenic potential. In this review, studies elucidating the biological effects of IR on bone cells (BMSCs, osteoblasts and osteoclasts) are summarized. Several potential preventions and therapies are also proposed.

A randomized multicenter clinical trial of 99 Tc-methylene diphosphonate in treatment of rheumatoid arthritis.

AIM: To investigate the efficacy and safety of technetium-99 conjugated with methylene diphosphonate (99 Tc-MDP, Yunke Pharmaceutical industry) in the treatment of rheumatoid arthritis (RA). METHODS: A total of 120 patients with active RA were randomly divided into three groups: Group A (receiving oral meloxicam tablets); Group B (receiving intravenous drip of 99 TC-MDP); Group C (receiving combination treatment of intravenous drip of 99 Tc-MDP and oral meloxicam tablets). The main clinical and laboratory parameters were evaluated at baseline and after 14 days of therapy. RESULTS: After 14 days of treatment, American College of Rheumatology 20 response was 15.62%, 34.04% and 48.78% in the three groups, respectively. The incidence of adverse events in three groups were 3.13%, 8.51% and 9.76% respectly, and has no significant difference. In addition, biochemical markers of bone metabolism including bone alkaline phosphatase (BAP), tartrate resistant acid phosphatase (TRAP) and dickkopf-1 (DKK-1), all improved in the three groups, although more significant in Group B than Group A, and more significant in the combination group than monotherapy groups. CONCLUSION: 99 Tc-MDP has good efficacy and safety in the treatment of active RA patients; the benefit was more remarkable when 99 Tc-MDP was combined with NSAIDs. 99 Tc-MDP may also have potential to improve bone metabolism.

Proteasome inhibitor bortezomib is a novel therapeutic agent for focal radiation-induced osteoporosis.

Bone atrophy and its related fragility fractures are frequent, late side effects of radiotherapy in cancer survivors and have a detrimental impact on their quality of life. In another study, we showed that parathyroid hormone 1-34 and anti-sclerostin antibody attenuates radiation-induced bone damage by accelerating DNA repair in osteoblasts. DNA damage responses are partially regulated by the ubiquitin proteasome pathway. In the current study, we examined whether proteasome inhibitors have similar bone-protective effects against radiation damage. MG132 treatment greatly reduced radiation-induced apoptosis in cultured osteoblastic cells. This survival effect was owing to accelerated DNA repair as revealed by γH2AX foci and comet assays and to the up-regulation of Ku70 and DNA-dependent protein kinase, catalytic subunit, essential DNA repair proteins in the nonhomologous end-joining pathway. Administration of bortezomib (Bzb) reversed the loss of trabecular bone structure and strength in mice at 4 wk after focal radiation. Histomorphometry revealed that Bzb significantly increased the number of osteoblasts and activity in the irradiated area and suppressed the number and activity of osteoclasts, regardless of irradiation. Two weeks of Bzb treatment accelerated DNA repair in bone-lining osteoblasts and thus promoted their survival. Meanwhile, it also inhibited bone marrow adiposity. Taken together, we demonstrate a novel role of proteasome inhibitors in treating radiation-induced osteoporosis.-Chandra, A., Wang, L., Young, T., Zhong, L., Tseng, W.-J., Levine, M. A., Cengel, K., Liu, X. S., Zhang, Y., Pignolo, R. J., Qin, L. Proteasome inhibitor bortezomib is a novel therapeutic agent for focal radiation-induced osteoporosis.

Extracorporeal Shock Wave Rebuilt Subchondral Bone In Vivo and Activated Wnt5a/Ca2+ Signaling In Vitro.

BACKGROUND: This study aimed to identify the optimal extracorporeal shock wave (ESW) intensity and to investigate its effect on subchondral bone rebuilt in vivo and Wnt5a/Ca2+ signaling in vitro using an osteoarthritis (OA) rat model and bone marrow mesenchymal stem cells (BMMSCs), respectively. METHODS: OA rats treated with (OA + ESW group) or without (OA group) ESW (n = 12/group) were compared with healthy controls (control group, n = 12). Gait patterns and subchondral trabecular bone changes were measured. Western blot and quantitative real-time polymerase chain reaction detected protein expression and gene transcription, respectively. RESULTS: The gait disturbances of OA + ESW group were significantly improved compared with the OA group at 6th and 8th weeks. The micro-CT analysis indicated that the BMD, BSV/BV, BV/TV, Tr.S, and Tr.Th are significantly different between OA group and OA + ESW group. Expression of Wnt5a was increased rapidly after ESW treatment at 0.6 bar and peaked after 30 min. CONCLUSIONS: ESW were positive for bone remodeling in joint tibial condyle subchondral bone of OA rat. ESW prevented histological changes in OA and prevented gait disturbance associated with OA progression. Optimal intensity of ESW induced changes in BMMSCs via activation of the Wnt5a/Ca2+ signaling pathway.

Effects of pulsed electromagnetic fields on postmenopausal osteoporosis.

Postmenopausal osteoporosis (PMOP) is considered to be a well-defined subject that has caused high morbidity and mortality. In elderly women diagnosed with PMOP, low bone mass and fragile bone strength have been proven to significantly increase risk of fragility fractures. Currently, various anabolic and anti-resorptive therapies have been employed in an attempt to retain healthy bone mass and strength. Pulsed electromagnetic fields (PEMFs), first applied in treating patients with delayed fracture healing and nonunions, may turn out to be another potential and effective therapy for PMOP. PEMFs can enhance osteoblastogenesis and inhibit osteoclastogenesis, thus contributing to an increase in bone mass and strength. However, accurate mechanisms of the positive effects of PEMFs on PMOP remain to be further elucidated. This review attempts to summarize recent advances of PEMFs in treating PMOP based on clinical trials, and animal and cellular studies. Possible mechanisms are also introduced, and the future possibility of application of PEMFs on PMOP are further explored and discussed. Bioelectromagnetics. 38:406-424, 2017. © 2017 Wiley Periodicals, Inc.

Effect of Low-intensity Pulsed Ultrasound on the Mandibular Remodeling Following Inferior Alveolar Nerve Transection.

Objective To investigate the effects of low-intensity pulsed ultrasound (LIPUS) on the mandibular remodeling following inferior alveolar nerve transection (IANX) and to optimize the parameters of LIPUS in the treatment of nerve injury. Methods IANX was performed in male Sprague-Dawley rats. Four weeks after IANX,the effect of daily LIPUS (from day 1) on the transected inferior alveolar nerve was examined in terms of sensitivity to mechanical stimulation. Moreover,histopathologic changes of mandibles were analyzed by micro-CT,HE staining,Masson trichrome staining,and immunohistochemical staining. Results LIPUS promoted the recovery of inferior alveolar nerve injury after transection. HE staining displayed the improvement of trabecular thickness and continuity. LIPUS with higher duty ratios had more obvious effect on bone remodeling. Conclusion LIPUS promotes the mandibular remodeling following IANX.

Changes of articular cartilage and subchondral bone after extracorporeal shockwave therapy in osteoarthritis of the knee.

We assessed the pathological changes of articular cartilage and subchondral bone on different locations of the knee after extracorporeal shockwave therapy (ESWT) in early osteoarthritis (OA). Rat knees under OA model by anterior cruciate ligament transaction (ACLT) and medial meniscectomy (MM) to induce OA changes. Among ESWT groups, ESWT were applied to medial (M) femur (F) and tibia (T) condyles was better than medial tibia condyle, medial femur condyle as well as medial and lateral (L) tibia condyles in gross osteoarthritic areas (p<0.05), osteophyte formation and subchondral sclerotic bone (p<0.05). Using sectional cartilage area, modified Mankin scoring system as well as thickness of calcified and un-calcified cartilage analysis, the results showed that articular cartilage damage was ameliorated and T+F(M) group had the most protection as compared with other locations (p<0.05). Detectable cartilage surface damage and proteoglycan loss were measured and T+F(M) group showed the smallest lesion score among other groups (p<0.05). Micro-CT revealed significantly improved in subchondral bone repair in all ESWT groups compared to OA group (p<0.05). There were no significantly differences in bone remodeling after ESWT groups except F(M) group. In the immunohistochemical analysis, T+F(M) group significant reduced TUNEL activity, promoted cartilage proliferation by observation of PCNA marker and reduced vascular invasion through observation of CD31 marker for angiogenesis compared to OA group (P<0.001). Overall the data suggested that the order of the effective site of ESWT was T+F(M) ≧ T(M) > T(M+L) > F(M) in OA rat knees.

Dosage effects of extracorporeal shockwave therapy in early hip necrosis.

BACKGROUND: This study investigated the effects of different dosages of extracorporeal shockwave therapy (ESWT) in early osteonecrosis of the femoral head (ONFH). MATERIALS AND METHODS: Thirty-three patients (42 hips) were randomly divided into three groups. Group A (10 patients with 16 hips) received 2000 impulses of ESWT at 24 Kv to the affected hip. Group B (11 patients with 14 hips) and Group C (12 patients with 12 hips) received 4000 and 6000 impulses of ESWT respectively. The evaluations included clinical assessment, radiographs, dynamic contrast-enhanced MRI for microcirculation (Ktrans) and plasma volume (Vp), and blood tests for biomarker analysis (NO3, VEGF, BMP-2, osteocalcin, TNF-α, IL-6, substance P, CGRP, DKK-1 and IGF). RESULTS: Significant differences of pain and Harris hip scores were noticed between Group A and C in 6 months after ESWT (all P < 0.05). The pain score decreased, but not Harris hip score improved over the observation time period from 6 to 24 months. Total hip arthroplasty was performed in 3 patients (4 hips) in Group A, but none in Groups B and C. Group C showed significant changes in serum biomarkers for angiogenesis, osteogenesis, anti-inflammation, pain threshold and tissue regeneration between one week and one month after treatment (all P < 0.05). However, no significant changes in the infarction volume in image studies were noted in all groups (all P > 0.05). The post-treatment Ktrans and Vp in the peri-necrotic areas of Group B and C were significantly greater than pre-treatment data (both P < 0.05). CONCLUSIONS: High dosage ESWT is more effective in early stage ONFH. The systemic beneficial effects of ESWT may ultimately enhance angiogenesis with improvement of microcirculation of the peri-necrotic areas, that in turn, can improve subchondral bone remodeling and prevent femoral head collapse.

Low-level laser therapy stimulates bone metabolism and inhibits root resorption during tooth movement in a rodent model.

This study evaluated the biological effects of low-level laser therapy (LLLT) on bone remodeling, tooth displacement and root resorption, occurred during the orthodontic tooth movement. Upper first molars of a total of sixty-eight male rats were subjected to orthodontic tooth movement and euthanized on days 3, 6, 9, 14 and 21 days and divided as negative control, control and LLLT group. Tooth displacement and histomorphometric analysis were performed in all animals; scanning electron microscopy analysis was done on days 3, 6 and 9, as well as the immunohistochemistry analysis of RANKL/OPG and TRAP markers. Volumetric changes in alveolar bone were analyzed using MicroCT images on days 14 and 21. LLLT influenced bone resorption by increasing the number of TRAP-positive osteoclasts and the RANKL expression at the compression side. This resulted in less alveolar bone and hyalinization areas on days 6, 9 and 14. LLLT also induced less bone volume and density, facilitating significant acceleration of tooth movement and potential reduction in root resorption besides stimulating bone formation at the tension side by enhancing OPG expression, increasing trabecular thickness and bone volume on day 21. Taken together, our results indicate that LLLT can stimulate bone remodeling reducing root resorption in a rat model. LLLT improves tooth movement via bone formation and bone resorption in a rat model.

Low-level laser therapy and invisible removal aligners.

It seems that Low Level Laser Therapy (LLLT) stimulates orthodontic tooth movements, increasing the alveolar bone turnover. The aim of this study is to evaluate how LLLT can influence the orthodontic treatment with invisible removal aligner. A sample of 21 subjects was divided into two groups, a laser group (10 patients) and a control group (11 patients). All subjects were instructed to wear each aligner 12 hours a day for 2 weeks. Laser external bio-stimulation was given in the laser group every second week. The laser group successfully finished the treatment, while at 3rd – 5th aligner the control group did not finish the treatment. Laser treatment seemed to be better than treatment without laser. LLLT combined with aligners is able to favour, in 12 hours, the same tooth movement obtained by wearing the aligner 22 hours a day, according to the traditional protocol. This aspect could be useful for those patients who prefer not to use the aligners during the day. LLLT makes invisible removal aligner treatment more comfortable also because during the day the patients have to wear the aligners less hours than the treatment without laser.

Bone marrow stem cell dysfunction in radiation-induced abscopal bone loss.

BACKGROUND: Bone-related complications are commonly reported in cancer patients receiving radiotherapy and are collectively referred to as the abscopal effect of irradiation, the mechanism of which remains poorly understood. When patients receive targeted radiotherapy to a tumor, the local skeleton is exposed to radiation, particularly within the bone marrow. We therefore investigated the hypothesis that single bone irradiation can induce deterioration of the skeleton outside the radiation field and is mediated by the bone marrow. METHODS: Using 4-month-old male Sprague-Dawley rats, the effects of irradiation (20 Gy, right distal femur and proximal tibia) on bone quality, microarchitecture and bone marrow, were evaluated prospectively by microcomputed tomography, histomorphometry, real-time polymerase chain reaction, and Western blot analysis. RESULTS: At 12 weeks post-irradiation, bone loss of the non-irradiated bone was induced and marrow adiposity was increased. Expression of runt-related transcription factor-2 by bone mesenchymal stem cells (BMSCs) decreased after irradiation by 88.0 % (P < 0.01) at the contralateral and 82.3 % (P < 0.01) at the irradiation site 2 weeks post-irradiation and decreased by 94.5 % (P < 0.001) at the contralateral and 44.1 % (P < 0.05) at the irradiation site 12 weeks post-irradiation. Interestingly, peroxisome proliferator-activated receptor gamma expression decreased by 61.8 % (P < 0.05) at the contralateral and by 48.3 % (P < 0.05) at the irradiation site 2 weeks post-irradiation but increased by 9-fold at the contralateral (P < 0.001) and by 13-fold (P < 0.001) at the irradiation site 12 weeks post-irradiation. CONCLUSIONS: These data highlight that radiation-induced bone complications are partly BMSC-mediated, with important implications for bone health maintenance in patients receiving radiotherapy.

Photobiomodulation and Lasers.

Photobiomodulation is discussed to be a noninvasive method to accelerate orthodontic tooth movement. The stimulatory effect of low-level laser therapy is well known and includes enhancement in tissue growth and tissue regeneration, resolvement of inflammation and pain. In recent research projects, the effect of laser therapy was tested regarding the stimulatory effect on bone remodeling with the potential to influence the tooth movement rate. The results are divers. The effect of laser regarding the reduction of the postadjustment pain could be proved, but not all authors describe the acceleration of tooth movement. Depending on the protocol, low-level laser therapy with low dosage increases the amount of tooth movement while high dosage seems to result in inhibitory effects. In conclusion, future studies are necessary to find the right protocol delivering beneficial results regarding the influence on bone remodeling and tooth movement to implement this therapy in daily orthodontic routine.

Re-irradiation for painful bone metastases: evidence-based approach.

The prognosis of patients with bone metastases has improved with the advent of increasingly effective systemic treatment and better supportive care. A growing number of bone metastases patients now outlive the duration of benefits from their initial treatment of radiotherapy (RT) while some patients fail to initially respond to RT. As such, re-irradiation (re-RT) may be required. The current review updates the literature on findings in the area of re-RT. In particular, the recent publication of the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) Symptom Control (SC20) trial shows that an 8 Gy treatment in a single fraction for re-RT is non-inferior and less toxic than 20 Gy in multiple fractions. Furthermore, patients responding to re-RT have experienced superior quality of life (QoL) and complain of less functional interference from pain; this provides a strong case in support of bone metastases patients being offered re-treatment. However, despite such findings, some specific patients will never respond to initial radiation or re-RT. New evidence suggests significant differences in bone markers between responders and non-responders, thus opening the possibility for further research into the use of such biomarkers for predicting prognosis and for the guidance of consequent treatment decisions.

Effect of low-level laser therapy on orthodontic tooth movement into bone-grafted alveolar defects.

INTRODUCTION: The objective of this study was to investigate the effect of low-level laser therapy (LLLT) on the rate of orthodontic tooth movement (OTM) into bone-grafted alveolar defects based on different healing states. METHODS: Ten male beagles were randomly allocated to 3 groups: group C, OTM alone as a control; group G, OTM into the grafted defects; group GL, OTM into the grafted defects with LLLT. The maxillary second premolars were protracted into the defects for 6 weeks, immediately (G-0 and GL-0) and at 2 weeks (G-2 and GL-2) after surgery. The defects were irradiated with a diode laser (dose, 4.5 J/cm(2)) every other day for 2 weeks. The rates of OTM and alveolar bone apposition, and maturational states of the defects were analyzed by histomorphometry, microcomputed tomography, and histology. RESULTS: The total amounts of OTM and new bone apposition rates were decreased by LLLT, with increased bone mineral density and trabecular maturation in the defects. Group GL-2 had the slowest movement with root resorption in relation to less woven bone in the hypermatured defect. CONCLUSIONS: LLLT significantly decreased the rate of OTM into the bone-grafted surgical defects by accelerating defect healing and maturation, particularly when the start of postoperative OTM was delayed.

Cancer treatment-induced bone loss (CTIBL): pathogenesis and clinical implications.

Osteopenia and osteoporosis are often long-term complications of anti-neoplastic treatments, defined as "cancer treatment-induced bone loss" (CTIBL). This pathological condition in oncologic patients results in a higher fracture risk than in the general population, and so has a significant negative impact on their quality of life. Hormone treatment is the main actor in this scenario, but not the only one. In fact, chemotherapies, radiotherapy and tyrosine kinase inhibitors may contribute to deregulate bone remodeling via different mechanisms. Thus, the identification of cancer patients at risk for CTIBL is essential for early diagnosis and appropriate intervention, that includes both lifestyle modifications and pharmacological approaches to prevent bone metabolism failure during anti-tumor treatments.

Comparing calvarial transport distraction with and without radiation and fat grafting.

The purpose of this study is to: a) assess transport distraction to reconstruct cranial defects in radiated and non-radiated fields b) examine adipose grafting's effect on the bony regenerate and overlying wound, and c) elucidate sources of bone formation during transport distraction osteogenesis. Twenty-three male New Zealand white rabbits (3 months; 3.5 kg) were used, 10 non-irradiated and 13 irradiated (17 treatment, 6 control) with a one-time fraction of 35 Gy. A 16 × 16 mm defect was abutted by a 10 × 16 mm transport disc 5 weeks after irradiation, and 11 animals were fat grafted at the distraction site. Latency (1 day), distraction (1.5 mm/day), and consolidation (4 weeks) followed. Fluorochromes were injected subcutaneously and microCT, fluorescence, and histology assessed. In distracted animals without fat grafting, bone density measured 701.87 mgHA/ccm and 2271.95 mgHA/ccm in irradiated and non-irradiated animals. In distracted animals with fat grafting, bone density measured 703.23 mgHA/ccm and 2254.27 mgHA/ccm in irradiated and non-irradiated animals. Fluorescence revealed ossification emanating from the dura, periosteum, and transport segment with decreased formation in irradiated animals. Transport distraction is possible for cranial reconstruction in irradiated fields but short-term osseous fill is significantly diminished. Adipose grafting enhances wound healing in previously irradiated fields but does not enhance ossification.