Skeletal and dental effects of tooth-borne versus hybrid devices for mandibular symphyseal distraction osteogenesis

Objective: To evaluate and compare, retrospectively, the skeletal and dental effects of mandibular symphyseal distraction osteogenesis (MSDO) achieved through the use of tooth-borne versus hybrid distractors.Materials and Methods:Pretreatment (T1), predistraction (T2), postdistraction (T3), and posttreatment (T4) orthodontic records were collected and analyzed for 47 patients (20 tooth-borne, 27 hybrid). At each time point, records included intraoral photographs, study models, postero-anterior cephalometric radiographs, and lateral cephalometric radiographs. Submental vertex radiographs were taken at T2, T3, and T4. Changes in a total of 18 measurements were analyzed to compare patients undergoing tooth-borne versus hybrid distraction.Results:The cumulative effects of orthodontics and MSDO produced similar gains in measured arch widths, with a decreased irregularity index in both groups (P > .05). However, there were differences in the timing during which the expansion was achieved. The hybrid distractor group gained space during the distraction phase of treatment. The tooth-borne group showed greater gains during pre- and postdistraction orthodontics. Comparisons of intercanine and interbone marker widths demonstrated a more parallel separation of bone during distraction with the hybrid distractor (P < .001). Distraction with the tooth-borne distractor was disproportionate, with greater separation of the canines in alveolar bone than of the bone markers in basal bone. During postdistraction orthodontics, the tooth-borne distractor group showed statistically greater increases in measurements.Conclusion:Both skeletal and dental expansion was achieved with both appliances. Greater skeletal expansion was achieved with a hybrid distractor. Greater dental expansion was achieved with a tooth-borne distractor.     

Effects of PEMF exposure at different pulses on osteogenesis of MC3T3-E1 cells

Objective

Pulsed electromagnetic fields (PEMFs) were considered to be a factor which may affect osteogenesis of osteoblasts, but the effects were diverse with different PEMF parameters. The aim of the current study is to explore the effects of exposure to PEMFs at different pulse number on osteogenesis of osteoblasts.

Design

The mouse osteoblast-like MC3T3-E1 cells were exposed to 0, 400 or 2800 pulses 400 kV/m PEMF and the proliferation, differentiation and mineralization of cells were observed after PEMF exposure by the methods of MTT, biochemical measurement, real-time PCR and Alizarin Red assay.

Results

Compared with 0 pulses groups, the growth curve, alkaline phosphatase (ALP) activity, mRNA level of osteocalcin (OCN) and mineralized nodule formation of MC3T3-E1 cells did not change after 400 pulses PEMF exposure, but decreased after 2800 pulses PEMF exposure. It suggested that under our experimental conditions, only 2800 pulses 400 kV/m PEMF exposure can suppress the proliferation, differentiation and mineralization of MC3T3-E1 cells, but 400 pulses 400 kV/m PEMF exposure cannot.

Conclusions

Pulse number is another involved parameter which may influence the effects of PEMF on osteogenesis of osteoblasts.     

The Osteoprint: A bioinspired two-photon polymerized 3-D structure for the enhancement of bone-like cell differentiation

The need for a better understanding of cell behavior and for exploiting cell functions in various healthcare applications has driven biomedical research to develop increasingly complex fabrication strategies to reproduce the natural biological microenvironment in vitro. Different approaches have led to the development of refined examples of 2- and 3-D structures able to sustain cellular proliferation, differentiation and functionality very similar to those normally occurring in living organisms. One such approach is two-photon polymerization. In this paper, we present a trabecula-like structure (which we have named “Osteoprint”) that resembles to the typical microenvironment of trabecular bone cells. Starting from microtomography images of the trabecular bone, we prepared several Osteoprints through two-photon polymerization and tested the behavior of SaOS-2 bone-like cells cultured on our structures. Interestingly, we found that Osteoprints deeply affect cellular behavior, determining an exit from the cell cycle and an enhancement of osteogenic differentiation. Indeed, we found an up-regulation of the genes involved in SaOS-2 cell maturation and an increase in hydroxyapatite production and accumulation upon SaOS-2 culture on the Osteoprints. The findings we obtained are extremely interesting, and open up new perspectives in “bioinspired” approaches for tissue engineering and regenerative medicine.     

Distraction Osteogenesis Maxillary Expansion (DOME) for adult obstructive sleep apnea patients with narrow maxilla and nasal floor

ObjectivesThis study correlates objective and subjective measurements associated with obstructive sleep apnea (OSA) to define the efficacy of Distraction Osteogenesis Maxillary Expansion (DOME) to treat adult OSA patients with narrow maxilla and nasal floor.MethodsThis is a retrospective study reviewing cases from September 2014 through April 2018 with 75 eligible subjects. Inclusion criteria required OSA confirmed by attended polysomnography (PSG). Pre- and Post-operative clinical data were measured at the Stanford Sleep Medicine and Stanford Sleep Surgery Clinics. DOME is a two-step process starting with insertion of custom-fabricated maxillary expanders anchored to the hard palate by mini-implants followed by minimally invasive osteotomies. After maxillary expansion was complete, orthodontic treatment to restore normal occlusion was initiated. Perioperative Apnea-Hypopnea Index (AHI), Epworth Sleepiness Scale (ESS), Nasal Obstruction Symptom Evaluation (NOSE), and Oxygen Desaturation Index (ODI) were measured for 43, 72, 72, and 34 subjects respectively. Statistical analysis was performed using paired T-test with significance set at p-value < 0.05.ResultsThe mean age of test subjects was 30.5 ± 8.5 years with a gender distribution of 57 males and 18 females. There was a significant reduction in pre and post-operative NOSE score (10.94 ± 5.51 to 3.28 ± 2.89, p < 0.0001), mean ESS score (10.48 ± 5.4 to 6.69 ± 4.75, p < 0.0001), and AHI (17.65 ± 19.30 to 8.17 ± 8.47, p < 0.0001) with an increased percentage of REM sleep (14.4 ± 8.3% to 22.7 ± 6.6%, p = 0.0014). No significant adverse effects were identified.ConclusionsDOME treatment reduced the severity of OSA, refractory nasal obstruction, daytime somnolence, and increased the percentage of REM sleep in this selected cohort of adults OSA patients with narrow maxilla and nasal floor.     

Immunocytochemical localization of BGP in human bones in various developmental stages and pathological conditions

Summary Bone-carboxyglutamic acid containing protein (BGP) was isolated from human bone and anti-BGP antibody was produced in rabbits. Localization of BGP was investigated immunocytochemically by light and electron microscopy in human bones in various developmental stages and pathological conditions. In the bones of a 12 week fetus, osteoblasts stained strongly in areas of bone formation. However in bones of late fetal stages and in newborns and adults, BGP was localized predominantly in the osteoid and bone matrix in the ossifying front. Osteoblasts and osteocytes also stained positive, but less dominantly than in the early fetus. Electron microscopy showed that BGP was localized in the ER and Golgi cisternae of osteoblasts and osteocytes, and the collagen fibers of the osteoid and bone matrix. The intensity and distribution of staining were not significantly different in osteoporosis and osteoarthritis. These observations indicate that BGP is synthesized by osteoblasts most actively in early fetal life and is then deposited on collagen fibers of the osteoid and bone matrix.     

雌激素对原代成骨细胞骨形成的影响

了解雌激素对培养的原代成骨细胞骨形成的影响。观察添加雌激素后直接对成骨细胞骨形成的作用，并用VOnKossa免疫染色法定量表示骨形成。结果显示：雌激素对该原代成骨细胞无促进骨形成作用。     

骨髓基质细胞体外培养骨发生潜能及条件研究

目的：建立一种骨髓基质细胞（ＢＭＳｃ）向成骨细胞转化的体外培养方法,观察其成骨过程,并探讨部分因子在ＢＭＳｃ转化及增殖中的作用。方法：将兔ＢＭＳｃ悬液进行体外培养,进行形态学观察和组织学检测;检测ｂＦＧＦ对ＢＭ－Ｓｃ的促增殖作用。结果：传代培养的细胞ＡＬＰ阳性率达８０％以上,细胞逐渐分化散在致密的岛状结构并分泌细胞外基质形成钙结节;ｂＦＧＦ能刺激ＢＭＳｃ的增殖。结论：培养的ＢＭＳｃ在体外仍具有成骨     

电穿孔介导的基因治疗对兔下颌骨牵引区新生骨骨密度与强度的影响

目的 探索电穿孔介导的基因治疗对下颌骨DO过程中牵引间隙新生骨密度与强度的影响,从而为促进下颌骨DO新骨生成,缩短牵引周期,减少并发症提供新思路.方法 以新西兰大白兔为实验动物模型,于术后3 d开始下颌骨牵引,每天0.8 mm,连续牵引7 d后,将实验动物分为5组.A组:在牵引区注射2 μg(O.1μg/μl)重组质粒pIRES-hVEGF165-hBMP2;B组:在牵引区注射2 μg(0.1μg/μl)重组质粒pIRES-hBMP2;C组:在牵引区注射2 μg(0.1μg/μl)重组质粒pIRES-hVEGF165;D组:在牵引区注射2 μg(0.1μg/μl)空质粒pIRES;E组:在牵引区注射相同剂量的生理盐水.5组实验动物均施加电穿孔刺激.各组分别于固定期第1、2、4、8周行X线及QCT检查.选整个牵张间隙新生骨痂部分为兴趣区,测定骨密度.然后处死动物.取材测量牵引区新生骨的三点抗压强度.结果 A、B、C组新生骨痂密度各时相点新生骨痂密度明显高于D、E组(P<0.01).固定2周,A组明显高于各组,但B、c组间比较差异无统计学意义.固定4周,A、B组明显高于C、D、E组(P<0.01).固定8周A组明显高于B、c、D、E组(P<0.01).B、C组间比较差异无统计学意义,但高于D、E组(P<0.01).固定4周,A组新生骨的三点抗压强度明显高于B、C、D、E组(P<0.01).固定8周,A组仍明显高于各组(P<0.01),且B组也明显高于c、D、E组(P<0.05).结论 电脉冲介导的pIRES-hVEGF165-hBMP2重组质粒体内转染可使牵引区获得较满意的骨再生和骨化成熟进程,其新骨骨化、改建过程均超过对照组.提示联合应用BMP与VEGF,可能会实现成骨与血供的联合重建,并且使单一生长因子的效应放大,使骨愈合的速度加快.     

An iatrogenic proximal radioulnar synostosis: a case report and review of literature

The most common cause of proximal radioulnar synostosis in adults is traumatic, usually after forearm fractures. Disabling complications are mainly loss of rotatory movements of the forearm. Various surgical procedures have been described in the literature to end up in forearm synostosis as a complication. We here presented a rare case of proximal forearm synostosis following a common but improper surgical technique for an olecranon fracture complicated by implant infection. The synostosis was treated by resection and fascia lata interposition graft.