Stress Distribution Analysis of Threaded Implants for Digital Dentistry.

In this study, stability evaluation is performed through structural analysis based on digital dental implant design variables. The design variables include the implant length and thickness, cortical bone thickness, and elastic modulus of the cancellous bone. Subsequently, the stress in the external cortical bone, in which numerous nerves exist, is analyzed.

Correlation of electrode position and clinical outcomes in globus pallidus stimulation for dystonia.

Background: The correlation between the electrode location and the clinical outcome for internal globus pallidus (GPi) deep brain stimulation (DBS) has not been fully elucidated.

Objective: The aim of this study was to determine the discrepancies between the theoretical target planned by magnetic resonance imaging (MRI) and the actual electrode location in postoperative MRI, as well as to find the correlation between the final electrode locations and the clinical outcome after GPi DBS.

Methods: Thirty-six patients who underwent GPi DBS for dystonia were included in this retrospective study.

Bilateral Deep Brain Stimulation of the Subthalamic Nucleus under Sedation with Propofol and Fentanyl.

Awakening during deep brain stimulation (DBS) surgery may be stressful to patients. The aim of the current study was to evaluate the effect on MER signals and their applicability to subthalmic nucleus (STN) DBS surgery for patients with Parkinson's disease (PD) under sedation with propofol and fentanyl. Sixteen consecutive patients with PD underwent STN-DBS surgery with propofol and fentanyl.

Long-Term Clinical Outcome of Internal Globus Pallidus Deep Brain Stimulation for Dystonia.

Background: GPi (Internal globus pallidus) DBS (deep brain stimulation) is recognized as a safe, reliable, reversible and adjustable treatment in patients with medically refractory dystonia.

Objectives: This report describes the long-term clinical outcome of 36 patients implanted with GPi DBS at the Neurosurgery Department of Seoul National University Hospital.

Methods: Nine patients with a known genetic cause, 12 patients with acquired dystonia, and 15 patients with isolated dystonia without a known genetic cause were included.

The clinical impact of precise electrode positioning in STN DBS on three-year outcomes.

Few studies have analyzed the clinical impact of subthalamic nucleus (STN) deep brain stimulation (DBS) as a function of the positioning of the inserted electrode. We investigated retrospectively the three-year outcomes in Parkinson's disease (PD) patients following bilateral STN DBS in terms of the electrode positions. Forty-one advanced PD patients were followed up for over three years following bilateral STN DBS.

Electrode position and the clinical outcome after bilateral subthalamic nucleus stimulation.

We compared the surgical outcome with electrode positions after bilateral subthalamic nucleus (STN) stimulation surgery for Parkinson's disease. Fifty-seven patients treated with bilateral STN stimulations were included in this study. Electrode positions were determined in the fused images of preoperative MRI and postoperative CT taken at six months after surgery.

Fusion image-based programming after subthalamic nucleus deep brain stimulation.

Objective: To propose fusion image-based programming to adjust patients with advanced Parkinson disease (PD) effectively after subthalamic nucleus (STN) deep brain stimulation (DBS).

Methods: Between January 2007 and July 2008, 38 patients with advanced PD were consecutively treated with STN DBS. The electrode positions and information regarding their contacts with STN were determined via fusion of the images of preoperative magnetic resonance imaging (MRI) and of postoperative computed tomography (CT) obtained 1 month after STN DBS.

Is MRI a reliable tool to locate the electrode after deep brain stimulation surgery? Comparison study of CT and MRI for the localization of electrodes after DBS.

Purpose: MRI has been utilized to localize the electrode after deep brain stimulation, but its accuracy has been questioned due to image distortion. Under the hypothesis that MRI is not adequate for evaluation of electrode position after deep brain stimulation, this study is aimed at validating the accuracy of MRI in electrode localization in comparison with CT scan.

Methods: Sixty one patients who had undergone STN DBS were enrolled for the analysis.

Comparison of electrode location between immediate postoperative day and 6 months after bilateral subthalamic nucleus deep brain stimulation.

Objective: We compared the electrode positions of subthalamic nucleus (STN) deep brain stimulation (DBS) estimated at the immediate postoperative period with those estimated 6 months after surgery.

Methods: Brain CT scans were taken immediately and 6 months after bilateral STN DBS in 53 patients with Parkinson's disease. The two images were fused using the mutual information technique.

Reprogramming guided by the fused images of MRI and CT in subthalamic nucleus stimulation in Parkinson disease.

Objective: To evaluate the usefulness of the visual information about the location of the contacts in deep brain stimulation (DBS) programming, we compared the outcomes of subthalamic nucleus (STN) stimulation before and after reprogramming guided by the fused images of MRI and CT.

Methods: Of the 65 patients with Parkinson's disease, who underwent bilateral STN-DBS surgery between March 2005 and September 2006 and had been managed for at least 6 months with conventional programming which was only based on the physiological responses from the patients, 54 patients were reprogrammed based on the 3D anatomical location of the contacts revealed by the fused images of pre-operative MRI and post-operative CT scans taken at 6 months after surgery. A total 51 patients completed the evaluation after reprogramming.

Electrode position determined by fused images of preoperative and postoperative magnetic resonance imaging and surgical outcome after subthalamic nucleus deep brain stimulation.

Objective: The electrode position is important to the surgical outcome after subthalamic nucleus (STN) deep brain stimulation (DBS). The aim of this study was to compare the surgical outcome of bilateral STN DBS with the electrode position estimated using fused magnetic resonance imaging.

Methods: Bilateral STN DBS was performed in 60 patients with advanced Parkinson's disease.