A prospective multicenter clinical investigation of a bone quality-based dental implant system

This article reports the 5-year interim results of an independently monitored, prospective, multicenter clinical trial of a bone quality-based implant design. At six study centers, 495 implants were placed in 151 cases with an average follow-up period of 1.6 years (range: 1.0-3.6 years) after prosthesis delivery. The majority of the implants were placed in D2 or D3 bone to support fixed partial dentures or implant-supported overdentures. Using strict success criteria, there were three implant failures, resulting in a cumulative 99.5% success rate according to Kaplan-Meier survival analysis. Radiographic analysis revealed a mean bone loss of 0.06 mm at 1 year and a bone gain of 0.04 mm at 2 years after prosthesis loading. There were no statistical differences in the results by center, implant type, bone density, area of the mouth, or prosthesis type. The results of this 5-year study revealed a high success rate and limited crestal bone loss in all bone densities by the use of an implant specifically designed for the varying biomechanical conditions and bone quality associated with the human maxilla and mandible.     

Myositis ossificans traumatica of the masseter muscle: Review of the literature and report of two additional cases

Myositis ossificans traumatica of the masseter muscle is uncommon. The condition is benign and results in reactive heterotopic bone formation, usually producing limitation of opening of the jaws. Radiographic and microscopic examination can confirm the diagnosis. Treatment of myositis ossificans traumatica of the masseter muscle is surgical, with other modalities used when occurring in other muscles of the body     

Quantitative Longitudinal Evaluation of Diaschisis-Related Cerebellar Perfusion and Diffusion Parameters in Patients with Supratentorial Hemispheric High-Grade Gliomas After Surgery

Decreased cerebral blood volume (CBV) in contralateral cerebellar gray matter (cGM) in conjunction with cerebellar white matter (cWM) damage, consistent with crossed cerebro-cerebellar diaschisis (cCCD) develop following supratentorial hemispheric stroke. In this study, we investigated the longitudinal evolution of diaschisis-related cerebellar perfusion and diffusion tensor-imaging (DTI) changes in patients after surgery for supratentorial brain tumors. Eight patients (M:F 5:3, age 8–22 years) who received surgery for supratentorial high-grade gliomas were evaluated. Initial MRI studies were performed 19–54 days postoperatively, with follow-ups at 2- to 3-month intervals. For each study, parametric maps of the cerebellum were generated and coregistered to T1-weighted images that had been previously segmented for cGM and cWM. Aggregate mean values of CBV, cerebral blood flow (CBF), and fractional anisotropy (FA) were obtained separately for cGM and cWM, and asymmetry indices (AIs) were calculated. Hemodynamic changes were more robust in cGM than in cWM. Seven patients showed decreased perfusion within cGM contralateral to the supratentorial lesion on the first postoperative study, and asymmetry was significant for both CBV (p?=?0.008) and CBF (p?p?p?=?0.0003), without evidence of subsequent recovery. Diaschisis-related hemodynamic alterations within cGM appear on early postoperative studies, but CBV recovers over time. Conversely, cWM DTI changes are delayed and progressive. Although the clinical correlates of cCCD are yet to be elucidated, better understanding of longitudinal structural and hemodynamic changes within brain remote from the area of primary insult could have implications in research and clinical rehabilitative strategies.     

The historic predictive value of Canadian orthopedic surgery residents’ orthopedic in-training examination scores on their success on the RCPSC certification examination

Background

Positive correlation between the orthopedic in-training examination (OITE) and success in the American Board of Orthopaedic Surgery examination has been reported. Canadian training programs in internal medicine, anesthesiology and urology have found a positive correlation between in-training examination scores and performance on the Royal College of Physicians and Surgeons of Canada (RCPSC) certification examination. We sought to determine the potential predictive value of the OITE scores of Canadian orthopedic surgery residents on their success on their RCPSC examinations.

Methods

A total of 118 Canadian orthopedic surgery residents had their annual OITE scores during their 5 years of training matched to the RCPSC examination oral and multiple-choice questions and to overall examination pass/fail scores. We calculated Pearson correlations between the in-training examination for each postgraduate year and the certification oral and multiple-choice questions and pass/fail marks.

Results

There was a predictive association between the OITE and success on the RCPSC examination. The association was strongest between the OITE and the written multiple-choice examination and weakest between the OITE and the overall examination pass/fail marks.

Conclusion

Overall, the OITE was able to provide useful feedback to Canadian orthopedic surgery residents and their training programs in preparing them for their RCPSC examinations. However, when these data were collected, truly normative data based on a Canadian sample were not available. Further study is warranted based on a more refined analysis of the OITE, which is now being produced and includes normative percentile data based on Canadian residents.     

Systemic Effects of Intracoronary Nitroglycerin during Coronary Angiography in Children after Heart Transplantation

Coronary spasm during coronary angiography for vasculopathy in children can be prevented by the intracoronary administration of nitroglycerin. We reviewed the anesthesia and catheterization reports and charts for pediatric transplant recipients who underwent angiography from 2005 through 2010. Correlation analysis was used to study the relation of post-injection systolic blood pressure (SBP) to nitroglycerin dose. Forty-one angiographic evaluations were performed on 25 patients (13 male and 12 female). Mean age was 9.9 ± 3.2 years (range, 3.3–16.1 yr). The mean total dose of nitroglycerin was 2.93 ± 1.60 µg/kg (range, 1–8 µg/kg).There was a significant drop between the baseline SBP (mean, 106 ± 21.6 mmHg) and the lowest mean SBP before nitroglycerin administration (78 ± 13.2, P <0.0001, paired t test). There was no significant additional change in SBP (mean after nitroglycerin administration, 80.7 ± 13.1 mmHg; P = 0.2). There was a significant drop in lowest heart rate between baseline (109 ± 16.5 beats/min) and before nitroglycerin administration (89 ± 14.3 beats/min; P <0.0001, paired t test). There was no significant additional change in heart rate (mean heart rate after nitroglycerin, 84 ± 17.7 beats/min; P = 0.09). There were 2 interventions for SBP before nitroglycerin and 2 after nitroglycerin. One child experienced a transient ST-T–segment change during angiography after nitroglycerin. In the highest dose range, the additional decrease in SBP was 7.2 mmHg (P=0.03). Routine intracoronary nitroglycerin administration in this dose range produced no significant changes in SBP or heart rate in children.Key words: Child, coronary angiography, coronary vasospasm/etiology, dose-response relationship, drug, heart transplantation/adverse effects, hemodynamics/drug effects, nitroglycerin/administration & dosage/therapeutic use, postoperative complications/therapy, retrospective studies, vasodilation/drug effectsAllograft coronary disease in children occurs with increasing frequency after transplantation, as a function of time. In a multicenter study,¹ the incidence of coronary artery disease in children 5 years post-transplant was 17% of all recipients. Coronary angiography remains the gold standard in the detection of vasculopathy in heart-transplant recipients.² Coronary artery spasm can complicate selective coronary angiography and result in myocardial ischemia. Coronary spasm can simulate the angiographic appearance of graft vasculopathy and cause diagnostic confusion.³ The spasm can arise from manipulation of the arterial wall by the catheter or from intraluminal injection of contrast material. In cardiac transplant recipients, coronary artery spasm has been reported in as many as 4.9% of coronary angiograms.³In adults, intracoronary nitroglycerin is routinely administered during coronary angiography to prevent coronary artery spasm.⁴ In children, however, safety and dosage guidelines for intracoronary nitroglycerin have not yet been firmly established. A dose of 3 µg/kg can be extrapolated by weight from the established adult dose of 200 µg; this dose was used in a study of children after the arterial switch operation and was shown to produce coronary vasodilation—with a small reduction in systolic blood pressure (SBP) and no noteworthy change in heart rate—in a control group of patients.^5,6We previously reported a case of coronary artery spasm during routine coronary angiographic monitoring in a 9-year-old boy who had undergone heart transplantation as an infant.⁷ After left main coronary artery injection of contrast material, the patient''s left anterior descending and left circumflex coronary arteries appeared to be diffusely narrow, and he developed marked ST-segment elevation, hypotension, and ventricular tachycardia. After cardiopulmonary resuscitation, he recovered uneventfully and displayed normal systolic function. Coronary angiography one month later, with the administration of intracoronary nitroglycerin before the injection of contrast material, revealed normal coronary artery diameter and was accomplished without complication.Since 2005, intracoronary nitroglycerin has routinely been used in pediatric transplant patients during biennial selective coronary angiographic monitoring at our institution. The purpose of the study is to report our experience with the routine use of intracoronary nitroglycerin for coronary angiography in children: its effects on blood pressure, on heart rate, and on the occurrence of arrhythmia and ST-segment elevation.     

Resolution of concomitant Achromobacter xylosoxidans burn wound infection without adjustment of antimicrobial therapy

Achromobacter xylosoxidans is part of an emerging group of Gram negative bacterial infections with potentially severe sequelae, especially in the immunocompromised population such as burn patients. While antimicrobial therapy for patients with A. xylosoxidans bacteremia has been reported, the literature is scarce with regard to treatment in patients with positive tissue cultures only. Herein, we report our institution''s experience with such a case and a brief review of the current literature on this micro-organism in the setting of non-bacteremic infection.KEY WORDS: Achromobacter xylosoxidans, alcaligenes xylosoxidans, burn, tissue culture