Accuracy of dental implant placement with computer-guided surgery: a retrospective cohort study.

BACKGROUND: The aim of this study was to assess the accuracy of virtual planning of computer-guided surgery based on the actual outcomes of clinical dental implant placement. METHODS: This retrospective study enrolled patients among whom implant treatment was planned using computer-guided surgery with cone beam computed tomography (CBCT). The patients who received implant according to the guide with the flapless and flapped approach were classified as group 1 and 2, respectively, and the others who could not be placed according to the guide were allocated to the drop-out group. The accuracy of implant placement was evaluated with the superimposition of CBCT. RESULTS: We analyzed differences in the deviated distance of the entrance point and deviated angulation of the insertion of implant fixtures. With regard to the surgical approach, group 2 exhibited greater accuracy compared to group 1 in deviation distance (2.22 ± 0.88 and 3.18 ± 0.89 mm, respectively, P < 0.001) and angulation (4.27 ± 2.30 and 6.82 ± 2.71°, respectively, P = 0.001). The limitations of guided surgery were discussed while considering the findings from the drop-out group. CONCLUSIONS: Computer-guided surgery demonstrates greater accuracy in implant placement with the flapless approach. Further research should be conducted to enhance the availability of guides for cases with unfavorable residual bone conditions.

Antiplatelet Therapy after Intracerebral Hemorrhage and Subsequent Clinical Events: A 12-Year South Korean Cohort Study.

INTRODUCTION: Antiplatelet agents are usually discontinued to reduce hemorrhagic tendency during the acute phase of intracerebral hemorrhage (ICH). However, their use after ICH remains controversial. METHODS: This study investigated the effect of antiplatelet agents in ICH survivors. We used the National Health Insurance Service-National Sample Cohort 2002-2013 database for retrospective cohort modeling, estimating the effects of antiplatelet therapy on clinical events. Subgroup analyses assessed antiplatelet medication administered before ICH. RESULTS: The prescription rate of antiplatelets after ICH was also examined. Of 1,007 ICH-surviving patients, 303 subsequent clinical events were recorded, 41 recurrences of nonfatal ICH recurrence, 26 incidents of nonfatal ischemic stroke, 6 nonfatal myocardial infarctions, and 230 incidents of all-cause mortality. The use of antiplatelet therapy significantly decreased the risk of primary outcomes (adjusted hazard ratio [AHR] = 0.743, 95% confidence interval [CI] = 0.578-0.956) and all-cause mortality (AHR = 0.740, 95% CI = 0.552-0.991), especially in patients without a history of antiplatelet treatment. The use of antiplatelet medication after ICH did not significantly increase the recurrence of ICH. The prescription rate of antiplatelet therapy within 1 year was 16.6%. Among 220 patients with a history of using antiplatelet medication, the resumption rate was 0.5% at discharge, 5% after a month, 12.7% after 3 months, and 29.1% after a year. CONCLUSION: Using antiplatelet treatment after ICH does not increase chances of recurrence, but lowers the occurrence of subsequent clinical events, especially mortality. However, the prescription and resumption rate of antiplatelet therapy after ICH remains low in South Korea.

Analysis of Sagittal Position Changes of the Condyle After Mandibular Setback Surgery Across the Four Different Types of Plating Systems.

ABSTRACT: The authors analyzed the three-dimensional postoperative condylar position change across the plating systems. This retrospective study was conducted with the patients who underwent bilateral sagittal split ramus osteotomy with setback surgery. The condylar change was analyzed from preoperative cone-beam computed tomography to postoperative 1 month (T1) and postoperative 6 months (T2) using superimposition software, automatically merging based on the anterior cranial base. The condylar changes during T1 and T2 were analyzed across the four types of plates (4-hole sliding, heart-shaped, 3-hole sliding, and 4-hole conventional) Mean intraclass correlation coefficient values were consistently high for each measurement (>0.850). During T1, the conventional plate had a decreased condylar anterior distance when compared with the 3-hole sliding plate (P = 0.032). During T2, the conventional plate had an increased condylar posterior distance when compared with the 3-hole sliding plate (P = 0.031). Superimposition software based on the anterior cranial base could be available for measurement of condylar position with highly reproducible results. After bilateral sagittal split ramus osteotomy, the 3-hole sliding plate could effectively compensate for the anterior displacement of the condyle compared to other plates.

Long-Term Clinical Evaluation of Short Implants on Posterior Partially Edentulous Areas: A 14-Year Retrospective Study.

PURPOSE: The clinical long-term outcomes of short implants are controversial. The aim of this study was to perform a long-term evaluation of short implants in posterior partially edentulous areas under various conditions. MATERIALS AND METHODS: This retrospective study was conducted with patients who had received 5- to 8-mm short implants to avoid bone grafts and spare anatomical structures between November 2005 and February 2014. Clinical outcomes (primary and secondary stability, marginal bone loss, and success and survival rates) were analyzed according to predictor variables of surgical procedure (submerged vs nonsubmerged), crown/implant ratio (1.5 and 2.0), type of prosthetic (single vs splinted crown), and arch location (maxilla vs mandible). The success rate was evaluated according to Albrektsson's criteria, and 5- and 10-year cumulative survival rates were calculated using Kaplan-Meier survival curves. RESULTS: A total of 148 patients (73 men, 75 women, mean age: 59.2 years) and 225 short implants were analyzed in this study. Over an average period of 6.21 ± 3.09 years, marginal bone loss was 0.43 ± 1.01 mm, and overall success and survival rates were 93.33% ± 25.0% and 97.78% ± 14.77%, respectively. Cumulative 5- and 10-year survival rates were 99.05% ± 0.65% and 96.72% ± 1.62%, respectively. CONCLUSION: Short implants (≤ 8 mm) in posterior edentulous areas showed comparable long-term outcomes of marginal bone loss and success and survival rates with conventional implants regardless of other clinical variables such as surgical procedure, crown/implant ratio, prosthetic type, and arch location.

Implication of left ventricular diastolic dysfunction in cryptogenic ischemic stroke.

BACKGROUND AND PURPOSE: Left ventricular diastolic dysfunction (LVDD) is a predictor for atrial fibrillation (AF). This study was aimed to investigate whether LVDD in cryptogenic ischemic stroke (CS) could be a clue to stroke mechanism. METHODS: The clinical and echocardiographic findings of 1589 consecutive patients with acute ischemic stroke or transient ischemic attack between 2004 and 2013 were reviewed. LVDDs among stroke subtypes were graded by transthoracic echocardiography into 4 groups by severity: normal, abnormal relaxation (grade I), pseudonormal (grade II), and restrictive diastolic filling (grade III), whereas severe LVDD was defined as grade III. We classified the lesion pattern of CS into cardioembolism-mimic or non-cardioembolism-mimic and determined whether cardioembolism-mimic lesions were associated with severe LVDD. RESULTS: The fraction of severe LVDD in CS was not different from that of stroke with AF (27.3% versus 37.1%; P=0.173) but was significantly higher than that of stroke without AF (27.3% versus 13.4%; P=0.008). Cardioembolism-mimic CS had more severe LVDD than non-cardioembolism-mimic CS (41.4% versus 11.5%; P=0.013). LVDD of grade II (odds ratio, 4.37; 95% confidence interval, 2.99-6.41) and grade III (odds ratio, 5.60; 95% confidence interval, 3.42-9.17) were independently related to stroke with AF after adjusting covariates. CONCLUSIONS: The severe LVDD could be a predictor of stroke with AF, and its frequency was similar between CS and stroke with AF. Cardioembolism-mimic CS had significantly more severe LVDD than non-cardioembolism-mimic CS. LVDD could be helpful to discriminate the stroke mechanism in the patients with acute CS.

Intracranial arterial calcification can predict early vascular events after acute ischemic stroke.

BACKGROUND: Intracranial arterial calcification (IAC) is an evidence of advanced atherosclerosis. This study was aimed to investigate whether IAC predicts early vascular events (EVEs) during acute period of ischemic stroke. METHODS: We prospectively enrolled consecutive patients with acute ischemic stroke and transient ischemic attack within 48 hours from January 2005 to October 2012. Three IAC categories were defined according to the total IAC score as follows: no IAC (0 point), mild IAC (1-2 points), and severe IAC (≥3 points). EVEs included early progression/recurrence of stroke, coronary events, and vascular deaths within 2 weeks from stroke onset. We used multivariable Cox regression analyses to determine the effect of IAC on EVE. RESULTS: In the trend analysis of 1017 total patients, there were significant trends of increased IAC toward higher total EVEs (10.5% versus 13.8% versus 21.2%, P < .001). Severe IAC was related to increased rate of early progression/recurrence (hazard ratio [HR] 2.00; 95% confidence interval [CI] 1.07-3.71, P = .029) and coronary events (HR 3.51; 95% CI 1.00-12.31, P = .050) but did not show an association for mortality (HR .54; 95% CI .19-1.53, P = .224). Increased IAC was also related to a poor functional outcome after 3 months (odds ratio 2.23; 95% CI 1.38-3.59). CONCLUSIONS: IAC was significantly associated with increased early progression/recurrence of stroke and coronary events during acute period of ischemic stroke. IAC on the initial brain computed tomography would be used as a predictor for recurrent vascular events after acute ischemic stroke before further angiographic evaluation.

Low glomerular filtration rate increases hemorrhagic transformation in acute ischemic stroke.

BACKGROUND: Decreased glomerular filtration rate (GFR) can increase the risk of bleeding tendency and hemorrhagic stroke. However, the relationship between the levels of GFR and hemorrhagic transformation (HT) after acute ischemic stroke is largely unknown. The aim of this study was to assess whether GFR level is associated with HT in acute ischemic stroke. METHODS: We reviewed 770 consecutive patients with acute ischemic stroke within 7 days from September 2007 to February 2012 in a prospective stroke registry database. We calculated the patient's GFR using the Cockcroft-Gault equation, and divided them into 3 groups: ≥60, 30-59 and <30 ml/min/1.73 m(2). HTs were identified by follow-up computed tomography (CT) or magnetic resonance imaging, and were defined as (1) any degree of high density within the area of low attenuation of vascular territory on noncontrast brain CT, or (2) low-signal intensity area in gradient echo within high-signal intensity meaning acute infarct on diffusion-weighted imaging. Multivariable logistic regression analyses were used to estimate the risk of GFR for HT. Stratification analyses were done according to the presence of HT high risk factors: atrial fibrillation (AF), thrombolysis and large size infarction. Additional logistic regression model for symptomatic HTs was established with the same variables. RESULTS: HTs were noted in 131 patients (17.0%) and symptomatic HTs in 63 patients (8.2%). In univariate analysis, HTs were more frequent in patients with AF (51.9 vs. 16.7%, p < 0.001) and large-size infarction (42.0 vs. 5.3%, p < 0.001). The risk of HT was associated with decreased GFR among 3 subgroups classified according to the value of estimated GFR: 49/394 (12.4%) in the GFR ≥60 group, 66/312 (21.2%) in the 30≤ GFR <59 group and 16/64 (25.0%) in the GFR <30 group (p = 0.002). We found a significant association between the GFR <30 group and HTs in acute ischemic stroke (OR 2.90; 95% CI 1.26-6.68, p = 0.012) after adjusting for other risk factors. Moreover, the incidence of HTs was higher in the subgroups without thrombolysis (OR 3.49; 95% CI 1.44-8.46) and without AF (OR 3.44; 95% CI 1.10-10.76). Decreased GFR also had a tendency of increasing symptomatic HTs (OR 2.39; 95% CI 0.72-7.94, p = 0.154). CONCLUSIONS: Low levels of GFR are associated with a high risk of HT after acute ischemic stroke. Further studies are needed to elucidate whether HT in the patients with renal insufficiency are related to a worse outcome after acute ischemic stroke.