Purpose The purpose of this study was to determine whether the surgical outcomes achieved with computer-aided surgical simulation (CASS) are better than those achieved with traditional methods. ...Materials and Methods Twelve consecutive patients with craniomaxillofacial (CMF) deformities were enrolled. According to the CASS clinical protocol, a 3-dimensional computer composite skull model for each patient was generated and reoriented to the neutral head posture. These models underwent 2 virtual surgeries: 1 was based on CASS (experimental group) and the other was based on traditional methods 1 year later (control group). Once the 2 virtual surgeries were completed, 2 experienced oral and maxillofacial surgeons at 2 different settings evaluated the 2 surgical outcomes. They were blinded to the planning method used on the virtual models and each other's evaluation results. The primary outcome was overall CMF skeletal harmony. The secondary outcomes were individual maxillary, mandibular, and chin harmonies. Statistical analyses were performed. Results Overall CMF skeletal harmony achieved with CASS was statistically significantly better than that achieved with traditional methods. In addition, the maxillary and mandibular surgical outcomes achieved with CASS were significantly better. Furthermore, although not included in the statistical model, the chin symmetry achieved by CASS tended to be better. A regression model was established between mandibular symmetry and overall CMF skeletal harmony. Conclusion The surgical outcomes achieved with CASS are significantly better than those achieved with traditional planning methods. In addition, CASS enables the surgeon to better correct maxillary yaw deformity, better place proximal/distal segments, and better restore mandibular symmetry. The critical step in achieving better overall CMF skeletal harmony is to restore mandibular symmetry.
Objective To test the hypothesis that high-risk ventilator-dependent extremely low birth weight (birth weight ≤1000 g) infants treated with 7 days of hydrocortisone will have larger total brain ...tissue volumes than placebo treated infants. Study design A predetermined sample size of 64 extremely low birth weight infants, between 10-21 days old and ventilator-dependent with a respiratory index score ≥2, were randomized to systemic hydrocortisone (17 mg/kg cumulative dose) or saline placebo. Primary outcome was total brain tissue volume. Volumetric magnetic resonance imaging was performed at 38 weeks postmenstrual age; brain tissue regions were segmented and quantified automatically with a high degree of accuracy and 9 structures were segmented manually. All analyses of regional brain volumes were adjusted by postmenstrual age at magnetic resonance imaging scan. Results The study groups were similar at baseline and 8 infants died in each arm. Unadjusted total brain tissue volume (mean ± SD) in the hydrocortisone (N = 23) and placebo treated infants (N = 21) was 272 ± 40.3 cm3 and 277.8 ± 59.1 cm3 , respectively (adjusted mean difference: 6.35 cm3 (95% CI: (−20.8, 32.5); P = .64). Three of the 31 hydrocortisone treated infants and 5 of the 33 placebo treated infants survived without severe bronchopulmonary dysplasia (relative risk 0.62, 95% CI: 0.13, 2.66; P = .49). No significant differences were noted in prespecified secondary outcomes of regional structural volumes or days on respiratory support. No adverse effects of hydrocortisone were observed. Conclusions Low dose hydrocortisone in high-risk ventilator-dependent infants after a week of age had no discernible effect on regional brain volumes or pulmonary outcomes prior to neonatal intensive care unit discharge.
Purpose The purpose of this study was to evaluate the clinical feasibility of a new method to orient 3-dimensional (3D) computed tomography models to the natural head position (NHP). This method uses ...a small and inexpensive digital orientation device to record NHP in 3 dimensions. This device consists of a digital orientation sensor attached to the patient via a facebow and an individualized bite jig. The study was designed to answer 2 questions: 1 ) whether the weight of the new device can negatively influence the NHP and 2 ) whether the new method is as accurate as the gold standard. Patients and Methods Fifteen patients with craniomaxillofacial deformities were included in the study. Each patient's NHP is recorded 3 times. The first NHP was recorded with a laser scanning method without the presence of the digital orientation device. The second NHP was recorded with the digital orientation device. Simultaneously, the third NHP was also recorded with the laser scanning method. Each recorded NHP measurement was then transferred to the patient's 3D computed tomography facial model, resulting in 3 different orientations for each patient: the orientation generated via the laser scanning method without the presence of the digital orientation sensor and facebow (orientation 1), the orientation generated by use of the laser scanning method with the presence of the digital orientation sensor and facebow (orientation 2), and the orientation generated with the digital orientation device (orientation 3). Comparisons are then made between orientations 1 and 2 and between orientations 2 and 3, respectively. Statistical analyses are performed. Results The results show that in each pair, the difference (Δ) between the 2 measurements is not statistically significantly different from 0°. In addition, in the first pair, the Bland-Altman lower and upper limits of the Δ between the 2 measurements are within 1.5° in pitch and within a subdegree in roll and yaw. In the second pair, the limits of the Δ in all 3 dimensions are within 0.5°. Conclusion Our technique can accurately record NHP in 3 dimensions and precisely transfer it to a 3D model. In addition, the extra weight of the digital orientation sensor and facebow has minimal influence on the self-balanced NHP establishment.
Purpose Current surgical planning methods are usually not adequate for the treatment of patients with complex craniomaxillofacial (CMF) deformities. To this end, we have developed a 3-dimensional ...(3D) computer-aided surgical simulation (CASS) planning method for the treatment of patients with complex CMF deformities. The purpose of this pilot study was to evaluate the accuracy of this technique in the treatment of patients with complex CMF deformities. Patients and Methods Five patients with complex CMF deformities were enrolled. Surgeries were planned with the CASS planning method. Surgical plans were transferred to patients at the time of surgery via computer-generated splints. After surgery, outcome evaluation was completed by first superimposing the postoperative computed tomography (CT) model onto the planned model, and then measuring the differences between planned and actual outcomes. The criteria used to determine the accuracy of the technique were as follows: a linear difference between planned and actual outcomes of less than 2 mm, and an angular difference of less than 4°. Results All patients underwent surgery as planned. With the use of CASS planning, medians of the differences between planned and actual postoperative outcomes were limited to 0.9 mm and 1.7°. Conclusion The results of this pilot study are promising. They will be used as the basis of calculations needed to determine the sample size for a larger and more comprehensive study that will be undertaken to assess the accuracy of CASS planning methods.
Background Asthma exacerbations are a major cause of morbidity and medical cost. Objective The objective of this study was to identify genetic predictors of exacerbations in asthmatic subjects. ...Methods We performed a genome-wide association study meta-analysis of acute asthma exacerbation in 2 pediatric clinical trials: the Childhood Asthma Management Program (n = 581) and the Childhood Asthma Research and Education (n = 205) network. Acute asthma exacerbations were defined as treatment with a 5-day course of oral steroids. We obtained a replication cohort from Biobank of Vanderbilt University Medical Center (BioVU; n = 786), the Vanderbilt University electronic medical record–linked DNA biobank. We used CD4+ lymphocyte genome-wide mRNA expression profiling to identify associations of top single nucleotide polymorphisms with mRNA abundance of nearby genes. Results A locus in catenin (cadherin-associated protein), alpha 3 (CTNNA3) , reached genome-wide significance (rs7915695, P = 2.19 × 10−8 ; mean exacerbations, 6.05 for minor alleles vs 3.71 for homozygous major alleles). Among the 4 top single nucleotide polymorphisms replicated in BioVU, rs993312 in Sema domain, immunoglobulin domain (Ig), short basic domain, secreted, (semaphorin) 3D (SEMA3D) was significant ( P = .0083) and displayed stronger association among African Americans ( P = .0004 in BioVU mean exacerbations, 3.91 vs 1.53; P = .0089 in the Childhood Asthma Management Program mean exacerbations, 6.0 vs 3.25). CTNNA3 variants did not replicate in BioVU. A regulatory variant in the CTNNA3 locus was associated with CTNNA3 mRNA expression in CD4+ cells from asthmatic patients ( P = .00079). CTNNA3 appears to be active in the immune response, and SEMA3D has a plausible role in airway remodeling. We also provide a replication of a previous association of purinergic receptor P2X, ligand-gated ion channel, 7 (P2RX7) , with asthma exacerbation. Conclusions We identified 2 loci associated with exacerbations through a genome-wide association study. CTNNA3 met genome-wide significance thresholds, and SEMA3D replicated in a clinical biobank database.
Purpose The purpose of the present study was to evaluate the accuracy of our newly developed approach to digital dental model articulation. Materials and Methods Twelve sets of stone dental models ...from patients with craniomaxillofacial deformities were used for validation. All the models had stable occlusion and no evidence of early contact. The stone models were hand articulated to the maximal intercuspation (MI) position and scanned using a 3-dimensional surface laser scanner. These digital dental models at the MI position served as the control group. To establish an experimental group, each mandibular dental model was disarticulated from its original MI position to 80 initial positions. Using a regular office personal computer, they were digitally articulated to the MI position using our newly developed approach. These rearticulated mandibular models served as the experimental group. Finally, the translational, rotational, and surface deviations in the mandibular position were calculated between the experimental and control groups, and statistical analyses were performed. Results All the digital dental models were successfully articulated. Between the control and experimental groups, the largest translational difference in mandibular position was within 0.2 mm ± 0.6 mm. The largest rotational difference was within 0.1° ± 1.1°. The averaged surface deviation was 0.08 ± 0.07. The results of the Bland and Altman method of assessing measurement agreement showed tight limits for the translational, rotational, and surface deviations. In addition, the final positions of the mandibular articulated from the 80 initial positions were absolutely agreed on. Conclusion The results of our study have demonstrated that using our approach, the digital dental models can be accurately and effectively articulated to the MI position. In addition, the 3-dimensional surface geometry of the mandibular teeth played a more important role in digital dental articulation than the initial position of the mandibular teeth.
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