A positron emission tomography radiomic signature for distant metastases risk in oropharyngeal cancer patients treated with definitive chemoradiotherapy.

BACKGROUND AND PURPOSE: Disease recurrence and distant metastases (DM) are major concerns for oropharyngeal cancer (OPC) patients receiving definitive chemo-radiotherapy. Here, we investigated whether pre-treatment primary tumor positron emission tomography (PET) features could predict progression-free survival (PFS) or DM. METHODS AND MATERIALS: Primary tumors were delineated on pre-treatment PET scans for patients treated between 2005 and 2018 using gradient-based segmentation. Radiomic image features were extracted, along with SUV metrics. Features with zero variance and strong correlation to tumor volume, stage, p16 status, age or smoking were excluded. A random forest model was used to identify features associated with PFS. Kaplan-Meier methods, Cox regression and logistic regression with receiver operating characteristics (ROC) and 5-fold cross-validated areas-under-the-curve (CV-AUCs) were used. RESULTS: A total of 114 patients were included. With median follow-up 40 months (range: 3-138 months), 14 patients had local recurrence, 21 had DM and 38 died. Two-year actuarial local control, distant control, PFS and overall survival was 89%, 84%, 70% and 84%, respectively. The wavelet_LHL_GLDZM_LILDE feature slightly improved PFS prediction compared to clinical features alone (CV-AUC 0.73 vs. 0.71). Age > 65 years (HR = 2.64 (95%CI: 1.36-5.2), p = 0.004) and p16-negative disease (HR = 3.38 (95%CI: 1.72-6.66), p < 0.001) were associated with poor PFS. A binary radiomic classifier strongly predicted DM with multivariable HR = 3.27 (95%CI: 1.15-9.31), p = 0.027, specifically for patients with p16-negative disease with 2-year DM-free survival 83% for low-risk vs. 38% for high-risk patients (p = 0.004). CONCLUSIONS: A radiomics signature strongly associated with DM risk could provide a tool for improved risk stratification, potentially adding adjuvant immunotherapy for high-risk patients.

Using Statistical Measures and Density Maps Generated From Chest Computed Tomography Scans to Identify and Monitor COVID-19 Cases in Radiation Oncology Rapidly.

Objectives This study aimed to evaluate quantitative and qualitative screening measures for anomalous computed tomography (CT) scans in cancer patients with potential coronavirus disease 2019 (COVID-19) as an automated detection tool in a radiation oncology treatment setting. Methods We identified a non-COVID-19 cohort and patients with suspected COVID-19 with chest CT scans from February 1, 2020 to June 30, 2020. Lungs were segmented, and a mean normal Hounsfield Unit (HU) histogram was generated for the non-COVID-19 CT scans; these were used to define thresholds for designating the COVID-19-suspected histograms as normal or abnormal. Statistical measures were computed and compared to the threshold levels, and density maps were generated to examine the difference between lungs with and without COVID-19 qualitatively. Results The non-COVID-19 cohort consisted of 70 patients with 70 CT scans, and the cohort of suspected COVID-19 patients consisted of 59 patients with 80 CT scans. Sixty-two patients were positive for COVID-19. The mean HUs and skewness of the intensity histogram discriminated between COVID-19 positive and negative cases, with an area under the curve of 0.948 for positive and 0.944 for negative cases. Skewness correctly identified 57 of 62 positive cases, whereas mean HUs correctly identified 17 of 18 negative cases. Density maps allowed for visualization of the temporal evolution of COVID-19 disease. Conclusions The statistical measures and density maps evaluated here could be employed in an automated screening algorithm for COVID-19 infection. The accuracy is high enough for a simple and rapid screening tool for early identification of suspected infection in patients treated with chemotherapy and radiation therapy already receiving CT scans as part of clinical care. This screening tool could also identify other infections that present critical risks for patients undergoing chemotherapy and radiation therapy, such as pneumonitis.

Association of Addition of Ablative Therapy Following Transarterial Chemoembolization With Survival Rates in Patients With Hepatocellular Carcinoma.

Importance: Hepatocellular carcinoma (HCC) is a heterogeneous disease with many available treatment modalities. Transarterial chemoembolization (TACE) is a valuable treatment modality for HCC lesions. This article seeks to evaluate the utility of additional ablative therapy in the management of patients with HCC who received an initial TACE procedure. Objective: To compare the overall survival (OS) and freedom from local progression (FFLP) outcomes after TACE alone with TACE that is followed by an ablative treatment regimen using stereotactic body radiation therapy, radiofrequency ablation, or microwave ablation for patients with HCC. Design, Setting, and Participants: This cohort study of 289 adults at a single urban medical center examined survival outcomes for patients with nonmetastatic, unresectable HCC who received ablative therapies following TACE or TACE alone from January 2010 through December 2018. The Lee, Wei, Amato common baseline hazard model was applied for within-patient correlation with robust variance and Cox regression analysis was used to assess the association between treatment group (TACE vs TACE and ablative therapy) and failure time events (FFLP per individual lesion and OS per patient), respectively. In both analyses, the treatment indication was modeled as a time-varying covariate. Landmark analysis was used as a further sensitivity test for bias by treatment indication. Exposures: TACE alone vs TACE followed by ablative therapy. Main Outcomes and Measures: Freedom from local progression and overall survival. Hypotheses were generated before data collection. Results: Of the 289 patients identified, 176 (60.9%) received TACE only and 113 (39.1%) received TACE plus ablative therapy. Ablative therapy included 45 patients receiving stereotactic body radiation therapy, 39 receiving microwave ablation, 20 receiving radiofrequency ablation, and 9 receiving a combination of these following TACE. With a median (interquartile range) follow-up of 17.4 (9.5-29.5) months, 242 of 512 (47.3%) lesions progressed, 211 in the group with TACE alone and 31 in the group with TACE plus ablative therapy (P < .001). Over 3 years, FFLP was 28.1% for TACE alone vs 67.4% for TACE with ablative therapy (P < .001). The 1-year and 3-year OS was 87.5% and 47.1% for patients with lesions treated with TACE alone vs 98.7% and 85.3% for patients where any lesion received TACE plus ablative therapy, respectively (P = .01), and this benefit remained robust on landmark analyses at 6 and 12 months. The addition of ablative therapy was independently associated with OS on multivariable analysis for all patients (hazard ratio, 0.26; 95% CI, 0.13-0.49; P < .001) and for patients with Barcelona clinic liver cancer stage B or C disease (hazard ratio, 0.31; 95% CI, 0.14-0.69; P = .004). Conclusions and Relevance: Adding ablative therapy following TACE improved FFLP and OS among patients with hepatocellular carcinoma. This study aims to guide the treatment paradigm for HCC patients until results from randomized clinical trials become available.

Trans-Carotid and Trans-Radial Access for Mechanical Thrombectomy for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis.

Objective We aim to demonstrate the safety and effectiveness of extra-femoral endovascular access for mechanical thrombectomy for acute ischemic stroke patients whose vascular anatomy precludes safe or maneuverable trans-femoral access. Methods Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to conduct a systematic review and meta-analysis with articles published until March 2018. The search protocol, including research questions and inclusion and exclusion criteria, were developed a priori. Our own institutional retrospective data were included in the cohort of case series. Results Eleven studies including 51 patients were included. Age ranged from 4th to 10th decade of life (average: 9.3rd decade) and 40.1% received IV tissue plasminogen activator. Initial National Institutes of Health Stroke Scale (NIHSS) score ranged from 1 to 36, (average: 17.6). Of the 51 patients, 39 (76%) patients suffered from anterior circulation large vessel occlusions versus 12 (24%) from posterior circulation occlusions. Site of access included 26 (51%) radial artery punctures, 23 (45%) direct percutaneous cervical carotid punctures, 1 brachial artery puncture, and 1 direct extradural vertebral artery puncture. Technical success was achieved in 43/51 (84%) of patients. The average modified Rankin Scale at discharge was 2.93 (n=26). There were no complications in 25 patients who underwent radial arterial access. Two (7.4%) of 27 cervical access patients developed hematoma. Conclusions Trans-carotid and trans-radial access for intervention in acute ischemic stroke is safe and effective. There may be instances in which these approaches should be considered first line before standard femoral approaches.

Risk of Ipsilateral Deep Vein Thrombosis After Use of AngioSeal Closure Device in Aneurysmal Subarachnoid Hemorrhage Patients.

BACKGROUND: Deep vein thrombosis (DVT) is a known complication in patients with aneurysmal subarachnoid hemorrhage (aSAH). This study investigated the association between use of the AngioSeal (St. Jude Medical, Minnetonka, MN) vascular closure device and the risk of ipsilateral and any DVT event after angiography in patients with aSAH. METHODS: We conducted a review of our institutional cerebral angiography database for the years 2005-2018 to identify all adult patients who underwent angiography for aSAH. We compared the incidence of DVT (occurring within 14 days) between aSAH patients who underwent manual compression versus the AngioSeal closure device. RESULTS: A total of 459 aSAH patients underwent angiography; 262 underwent manual compression (57.1%) and 197 received AngioSeal (42.9%). There was a 3.4% rate of ipsilateral DVT in the manual compression group and 7.6% in the AngioSeal closure device group (χ2 test, P = 0.04). Similarly, the rate of any DVT was 8.8% for manual compression and 16.8% for patients who received AngioSeal (χ2 test, P = 0.01). On multivariate analysis, AngioSeal remained a significant independent predictor of ipsilateral DVT (odds ratio 2.4, P = 0.04) and any DVT (odds ratio 2.3, P = 0.01). CONCLUSIONS: In aSAH patients undergoing cerebral angiographic procedures with access through the femoral artery, the use of AngioSeal closure device was found to be associated with a significantly increased risk of ipsilateral DVT within 14 days.

Comparing outcomes following total neoadjuvant therapy and following neoadjuvant chemoradiation therapy in patients with locally advanced rectal cancer.

BACKGROUND: There is recent interest in treating locally advanced rectal cancer (LARC) patients with total neoadjuvant therapy (TNT). However, whether TNT is associated with improved overall survival (OS) remains unknown. This study compares outcomes following TNT and following neoadjuvant chemoradiation therapy (nCRT) in patients with LARC, clinically defined cT3/4 or node positive disease, using the National Cancer Database. METHODS: LARC patients diagnosed between 2004-2015 were included. TNT was defined as multi-agent chemotherapy given at least 2 months before RT followed by pre-operative chemoradiation therapy and definitive surgery without adjuvant chemotherapy. nCRT was defined as pre-operative RT and chemotherapy started within 2 weeks from each other followed by definitive surgery with or without adjuvant chemotherapy. Kaplan-Meier curve with logrank test and multivariable Cox proportional hazards regression modelling were used to analyse the primary endpoint of overall survival (OS). Multivariable logistic regression modelling was used for secondary outcomes to determine if TNT is associated with pathological complete response (pCR), defined as ypT0N0, and negative circumferential resection margin (CRM). FINDINGS: Data from 372 TNT patients and 707 nCRT patients were analysed after a 2:1 propensity matching with replacement. Kaplan-Meier curve showed that OS with TNT was comparable to that with nCRT (p = 0•16). The 5-year OS rates for TNT and nCRT were 73•6% vs. 78•5% (p = 0•20). Multivariable Cox proportional hazards regression modelling confirmed no difference in OS between TNT and nCRT (HR = 1•21, p = 0•25). With TNT, 16•9% patients achieved pCR, whereas 13•1% patients achieved pCR with nCRT (p = 0•12). TNT was not found to be significantly associated with pCR (OR = 1•36, p = 0•13) or negative CRM (OR = 1•77, p = 0•19) in multivariable logistic regression modelling. INTERPRETATION: With results from current clinical trials pending, our data suggested that TNT and nCRT resulted in similar survival, while TNT led to higher pCR and CRM negative rate, albeit not statistically significant.

Early postnatal overnutrition accelerates aging-associated epigenetic drift in pancreatic islets.

Pancreatic islets of type 2 diabetes patients have altered DNA methylation, contributing to islet dysfunction and the onset of type 2 diabetes. The cause of these epigenetic alterations is largely unknown. We set out to test whether (i) islet DNA methylation would change with aging and (ii) early postnatal overnutrition would persistently alter DNA methylation. We performed genome-scale DNA methylation profiling in islets from postnatally over-nourished (suckled in a small litter) and control male mice at both postnatal day 21 and postnatal day 180. DNA methylation differences were validated using quantitative bisulfite pyrosequencing, and associations with expression were assessed by RT-PCR. We discovered that genomic regions that are hypermethylated in exocrine relative to endocrine pancreas tend to gain methylation in islets during aging (R 2 = 0.33, P < 0.0001). These methylation differences were inversely correlated with mRNA expression of genes relevant to ß cell function [including Rab3b (Ras-related protein Rab-3B), Cacnb3 (voltage-dependent L-type calcium channel subunit 3), Atp2a3 (sarcoplasmic/endoplasmic reticulum calcium ATPase 3) and Ins2 (insulin 2)]. Relative to control, small litter islets showed DNA methylation differences directly after weaning and in adulthood, but few of these were present at both ages. Surprisingly, we found substantial overlap of methylated loci caused by aging and small litter feeding, suggesting that the age-associated gain of DNA methylation happened much earlier in small litter islets than control islets. Our results provide the novel insights that aging-associated DNA methylation increases reflect an epigenetic drift toward the exocrine pancreas epigenome, and that early postnatal overnutrition may accelerate this process.

A novel hybrid fixation versus dual plating for both-bone forearm fractures in older children: A prospective comparative study.

OBJECTIVE: The aim of the present study was to compare the clinical outcomes of hybrid fixation using elastic stable intramedullary nailing (ESIN) for the ulna and plate screw fixation for the radius (Hybrid group) with dual plating fixation for both-bone forearm fractures in children between 10 and 16 years of age. METHODS: Twenty-six patients were treated using a hybrid fixation struct and 30 patients were treated with dual plating fixation. The two groups were compared prospectively according to perioperative data and patient outcome measures. RESULT: The hybrid fixation construct group had 26 patients, with a mean age of 13.27 years (range, 10-16 years) and the dual plate group had 30 patients, with a mean age of 13.33 years (range, 10-16 years). The groups were similar for sex, arm injured, fracture location. Incision length of ulna, duration of surgery and hospital costs were significantly different between the two groups (P < 0.05). There was no significant difference in either time to union or Price scores for function evaluation between the 2 groups (P < 0.05). Complication rates were also similar between the groups. CONCLUSION: Hybrid fixation, using open reduction and internal fixation with a plate-and-screw construct on the radius and closed reduction and elastic intramedullary fixation of the ulna, is an acceptable method for treating both-bone diaphyseal forearm fractures in skeletally immature patients 10-16 years old. The small incision and less cost are the characteristics of this hybrid fixation.

[Comparison of the clinical effects between Dihuang Decoction and alendronate sodium in the treatment of primary osteoporosis].

OBJECTIVE: To study and compare the clinical effects of Rehmannia Decoction and alendronate sodium for the treatment of primary osteoporosis. METHODS: From January 2016 to December 2017, 72 patients with primary osteoporosis who took Dihuang Decoction(DHD) orally and alendronate regularly for more than one year were randomly divided into 2 groups:experimental group and control group. The experimental group consisted of 14 males and 22 females, with an average age of(63.97±3.70) years old. The patients in the experimental group took Chinese medicine DHD, one dose each time, one time in the morning and one time in the evening, twice a week. The control group consisted of 16 males and 20 females with an average age of(63.36±3.07) years old. Patients in the control group were given alendronate 70 mg orally once a week. The basic treatment for osteoporosis remained unchanged in both groups(600 mg of calcium carbonate D3 and 0.5 µg of calcitriol capsules were taken daily). Bone mineral density (BMD) of femoral neck and lumbar vertebrae was measured by dual energy X-ray absorptiometry before and after treatment for one year. The levels of serum collagen type I C-terminal peptide (beta-CTX) and serum osteoclast (SOST) were measured before and after treatment for two groups. RESULTS: The age, bone mineral density, SOST and beta-CTX baseline values between the two groups before and after anti-osteoporosis treatment were compared. The difference was not statistically significant(P>0.05). Compared with the two groups, the BMD of femoral neck and lumbar vertebrae were increased after 1 year of anti-osteoporosis treatment. The differences were statistically significant (P<0.001). The value of serum beta-CTX was significantly lower than before. The t values were 52.002 and 50.071 respectively. The value of serum SOST was increased than that before treatment. The t values were -29.242 and -30.807 respectively. The differences were statistically significant (P<0.001). BMD of the femoral neck and lumbar spine was compared between the two groups after treatment. The P values were 0.294 and 0.478 respectively. The difference was not statistically significant (P>0.05). The serum beta-CTX values were compared between the two groups after treatment. The P value was 0.908. The serum SOST values were compared between the two groups after treatment. The P value was 0.888. The difference was not statistically significant (P>0.05). CONCLUSIONS: In this study, traditional Chinese medicine DHD is used to treat osteoporosis. It is found that DHD and alendronate have a good effect. The DHD can be used as a choice of Chinese medicine in the treatment of primary osteoporosis.

17ß-Estradiol/extrogen receptor ß alleviates apoptosis and enhances matrix biosynthesis of nucleus pulposus cells through regulating oxidative damage under a high glucose condition.

BACKGROUND: Hyperglycemia in the Diabetes mellitus (DM) patients is a potential etiology of disc degeneration. 17ß-estradiol (17ß-E2) supplementation plays an anti-diabetic role in DM patients. OBJECTIVE: This study was aimed to investigate the role and mechanism of 17ß-E2 in regulating nucleus pulposus (NP) cell apoptosis and NP matrix production under a high glucose condition. METHODS: Rat NP cells were cultured in medium with a high glucose concentration (0.2 M). 17ß-E2 was added into the culture medium to investigate its protective effects. The ERß inhibitor PHTPP and ERß activator ERB041 were used to investigate the effects of ERß. NP cell apoptosis was analyzed by flow cytometry and expression of apoptosis-related molecules. NP matrix production was evaluated by expression of matrix macromolecules. Additionally, intracellular reactive oxygen species (ROS) content was also detected. RESULTS: Compared with the control NP cells, 17ß-E2 decreased NP cell apoptosis ratio, down-regulated gene expression of Bax and caspase-3, up-regulated gene expression of Bcl-2, increased protein expression of cleaved PARP and cleaved caspase-3, and increased expression of matrix molecules (aggrecan and collagen II). Moreover, 17ß-E2 decreased ROS content. Further analysis showed that ERß inhibition partly reversed these effects of 17ß-E2 whereas ERß activation further promoted its effects. CONCLUSION: 17ß-E2/ERß interaction attenuates apoptosis and promotes matrix biosynthesis of NP cells through alleviating oxidative damage under a high glucose condition. This study provides new knowledge on strategies for retarding disc degeneration.

Asymmetrical traumatic bilateral hip dislocations with hemodynamic instability and an unstable pelvic ring: Case report and review of literature.

Simultaneous anterior and posterior traumatic dislocations of both hips are very rare. Only 33 cases have been previously reported in the English language literature. Although they were all due to high-energy injuries, they were hemodynamically stable and had a stable pelvic ring. We report a unique case of asymmetrical hip dislocations with an unstable pelvic ring and hemodynamic instability. A 40-year-old man was injured in a high-energy motor vehicle accident. He was hemodynamically unstable when he presented in the emergency department. Radiolographs showed asymmetrical dislocations of both hips with an unstable pelvic ring. Under general anesthesia, he had closed reduction of the dislocations of both hips, followed by temporary stabilization with an external fixator. Transcatheter arterial embolization was performed to stop active pelvic bleeding. Delayed open reduction and internal fixation was performed 12 days later with anterior and posterior plates. The patient recovered well with an uneventful post-operative course. Asymmetrical bilateral hip dislocations with pelvic ring instability caused by trauma, as presented in this case, is very rare and potentially life threatening. Prompt treatment can give a good outcome.

Maternal exercise during pregnancy promotes physical activity in adult offspring.

Previous rodent studies have shown that maternal voluntary exercise during pregnancy leads to metabolic changes in adult offspring. We set out to test whether maternal voluntary exercise during pregnancy also induces persistent changes in voluntary physical activity in the offspring. Adult C57BL/6J female mice were randomly assigned to be caged with an unlocked (U) or locked (L) running wheel before and during pregnancy. Maternal running behavior was monitored during pregnancy, and body weight, body composition, food intake, energy expenditure, total cage activity, and running wheel activity were measured in the offspring at various ages. U offspring were slightly heavier at birth, but no group differences in body weight or composition were observed at later ages (when mice were caged without access to running wheels). Consistent with our hypothesis, U offspring were more physically active as adults. This effect was observed earlier in female offspring (at sexual maturation). Remarkably, at 300 d of age, U females achieved greater fat loss in response to a 3-wk voluntary exercise program. Our findings show for the first time that maternal physical activity during pregnancy affects the offspring's lifelong propensity for physical activity and may have important implications for combating the worldwide epidemic of physical inactivity and obesity.-Eclarinal, J. D., Zhu, S., Baker, M. S., Piyarathna, D. B., Coarfa, C., Fiorotto, M. L., Waterland, R. A. Maternal exercise during pregnancy promotes physical activity in adult offspring.

Comparison of Hybrid Fixation to Dual Plating for Both-Bone Forearm Fractures in Older Children.

When operative stabilization of forearm fractures in older children is necessary, the optimal method of fixation is controversial. This study compared the radiographic and functional outcomes of dual plating to a hybrid fixation construct with elastic intramedullary nailing of the radius and plate fixation of the ulna of forearm fractures in children aged between 10 and 16 years. Nineteen patients were treated using a hybrid fixation construct and 13 patients were treated with dual plating fixation. The 2 groups were compared retrospectively according to perioperative data and patient outcome measures. The hybrid fixation construct group had 19, with a mean age of 13.3 years (range, 10-16 years) and the dual plate group had 13 patients, with a mean age of 12.9 years (range, 10-16 years). Groups were similar for sex, arm injured, and fracture location. Duration of surgery and tourniquet use was significantly shorter in the hybrid fixation construct group. There was no significant difference in either time to union or Price scores for function evaluation between the 2 groups. Complication rates were also similar between groups, with 1 ulna delayed unions, 1 superficial infection at entry of nail in hybrid fixation construct group, and 1 ulna delayed unions in the dual plating group. Hybrid fixation, using open reduction and internal fixation with a plate-and-screw construct on the ulna and closed reduction and elastic intramedullary fixation of the ulna, is an acceptable method for treating both-bone diaphyseal forearm fractures in skeletally immature patients aged 10-16 years.

Developmental programming of energy balance regulation: is physical activity more 'programmable' than food intake?

Extensive human and animal model data show that environmental influences during critical periods of prenatal and early postnatal development can cause persistent alterations in energy balance regulation. Although a potentially important factor in the worldwide obesity epidemic, the fundamental mechanisms underlying such developmental programming of energy balance are poorly understood, limiting our ability to intervene. Most studies of developmental programming of energy balance have focused on persistent alterations in the regulation of energy intake; energy expenditure has been relatively underemphasised. In particular, very few studies have evaluated developmental programming of physical activity. The aim of this review is to summarise recent evidence that early environment may have a profound impact on establishment of individual propensity for physical activity. Recently, we characterised two different mouse models of developmental programming of obesity; one models fetal growth restriction followed by catch-up growth, and the other models early postnatal overnutrition. In both studies, we observed alterations in body-weight regulation that persisted to adulthood, but no group differences in food intake. Rather, in both cases, programming of energy balance appeared to be due to persistent alterations in energy expenditure and spontaneous physical activity (SPA). These effects were stronger in female offspring. We are currently exploring the hypothesis that developmental programming of SPA occurs via induced sex-specific alterations in epigenetic regulation in the hypothalamus and other regions of the central nervous system. We will summarise the current progress towards testing this hypothesis. Early environmental influences on establishment of physical activity are likely an important factor in developmental programming of energy balance. Understanding the fundamental underlying mechanisms in appropriate animal models will help determine whether early life interventions may be a practical approach to promote physical activity in man.

Computed tomography morphometric analysis of anterior instrumentation in the pediatric thoracic spine.

OBJECT The authors' goal in this paper was to quantify reference data on the dimensions and relationships of the maximum posterior screw angle and the thoracic spinal canal in different pediatric age groups. METHODS One hundred twelve pediatric patients were divided into 4 age groups, and their thoracic vertebrae were studied on CT scans. The width, depth, and maximum posterior screw angles with different screw entrance points were measured on a Philips Brilliance 16 CT. The statistical analysis was performed using the Student t-test and Pearson's correlation analysis. RESULTS The width and depth of the thoracic vertebrae increased from T-5 to T-12. The width ranged from 18.5 to 37.1 mm, while the depth ranged from 16.1 to 28.2 mm. The maximum posterior screw angle decreased from T-5 to T-12 in all groups. The ranges and mean angles at the entrance points were as follows: initial entrance point, 6.9° to 12.3° with a mean angle of 9.1°; second entrance point, 20.6° to 27.0° with a mean angle of 24.2°; and third entrance point, 29.2° to 37.5° with a mean angle of 33.7°. There were no significant age-related differences noted for the maximum posterior screw angles. CONCLUSIONS The angle decreased from T-5 to T-12. No significant age-related differences were noted in the maximum posterior screw angles. Screws should be placed between the initial and second points and parallel to the coronal section or at a slight anterior orientation.

Formation and bioactivity of HA nanorods on micro-arc oxidized zirconium.

A microporous and CaO partially stabilized zirconia (Ca-PSZ) coating covered with hydroxyapatite (HA) nanorods is fabricated on Zr substrate by a hybrid approach of micro-arc oxidation (MAO) and hydrothermal treatment (HT). The effect of P ions in HT solution on the density and morphology of HA was investigated; the hydrophilicity and apatite-forming ability of the Ca-PSZ coating with HA nanorods were also examined. High-density HA nanorods (with a mean diameter of 50 nm and length of 450 nm) grow on the Ca-PSZ coating after HT in a solution containing 0.002 M ß-glycerophosphate disodium (ß-GP). However, only a few of coarse-grained HA crystallites grow in the MAOed pores after HT in distilled water or in an ammonia aqueous solution with an initial pH value equal to the solution containing 0.002 M ß-GP. P ions in the HT solution are thought to significantly promote the formation of HA nanorods. The Ca-PSZ coating covered with HA nanorods displays good hydrophilicity and excellent apatite-inducing ability, and the induced apatite prefers to nucleate on the basal-faceted surfaces of HA nanorods.