Reproducible and flexible simulation experiments with ML-Rules and SESSL.

Summary: The modeling language ML-Rules allows specifying and simulating complex systems biology models at multiple levels of organization. The development of such simulation models involves a wide variety of simulation experiments and the replicability of generated simulation results requires suitable means for documenting simulation experiments. Embedded domain-specific languages, such as SESSL, cater both requirements. With SESSL, the user can integrate diverse simulation experimentation methods and third-party software components into an executable, readable simulation experiment specification. A newly developed SESSL binding for ML-Rules exploits these features of SESSL, opening up new possibilities for executing and documenting simulation experiments with ML-Rules models. Availability and Implementation: ML-Rules is implemented in Java, SESSL and its bindings are implemented in Scala. The source code is available under open-source licenses: ML-Rulesgit.informatik.uni-rostock.de/mosi/mlrules2ML-Rules Quickstart (Graphical Editor)git.informatik.uni-rostock.de/mosi/mlrules2-quickstartSESSLgit.informatik.uni-rostock.de/mosi/sessl and sessl.orgSESSL Quickstart (Experiment Template)git.informatik.uni-rostock.de/mosi/sessl-quickstart Furthermore, Maven-compatible compiled packages of ML-Rules, SESSL, and the SESSL bindings are available from the Maven Central Repository at maven.org (org.sessl:* and org.jamesii:mlrules). Supplementary Material: The supplementary material contains a more complex case study that exemplifies the usage of the SESSL binding for ML-Rules. Contact: tom.warnke@uni-rostock.de.

Frontal sinus fractures: computed tomography evaluation of sinus obliteration with lyophilized cartilage.

Allogenic lyophilized cartilage has been proven clinically to be a reliable material for obliteration of the frontal sinus without the limitations of donor site morbidity and the prolongation of the operation time produced by autogenic grafting. The long-term behaviour of the implanted material is of paramount importance for the success of the obliterative technique. This survey included 51 trauma patients on whom obliteration of the frontal sinus with lyophilized cartilage was performed. The fate of the lyophilized cartilage graft was evaluated from computed tomography imaging of the obliterated frontal sinus. No radiological sign of mucocele formation or inflammatory disease was noted. Bone density measurement of the obliterated sinus and the adjacent trabecular bone was calculated. The patient population was distributed into four groups (0-2, 2-4, 4-6, > 6 years) according the postobliterative time. The bone density of the implanted lyophilized cartilage was accentuated from group 1 to group 4 when compared with the bone density of the trabecular bone. This shows the long-term tendency of lyophilized cartilage graft to osseous substitution.

The value of stereolithographic models for preoperative diagnosis of craniofacial deformities and planning of surgical corrections.

The purpose of this study was to assess the importance of stereolithographic models (SLMs) for preoperative diagnosis and planning in craniofacial surgery and to examine whether these models offer valuable additional information as compared to normal CT scans and 3D CT images. Craniofacial SLMs of 20 patients with craniomaxillofacial pathology were made. A helical volume CT scan of the anatomic area involved delivered the necessary data for their construction. These were built with an SLA 250 stereolithography apparatus (3D-Systems, Valencia, CA, USA), steered by FORM-IT/DCS software (University of Zurich, Switzerland). The stereolithography models were classified according to pathology, type of surgery and their relevance for surgical planning. Though not objectively measurable, it was beyond doubt that relevant additional information for the surgeon was obtained in cases of hypertelorism, severe asymmetries of the neuro- and viscerocranium, complex cranial synostoses and large skull defects. The value of these models as realistic "duplicates" of complex or rare dysmorphic craniofacial pathology for the purpose of creating a didactic collection should also be emphasized. The models proved to be less useful in cases of consolidated fractures of the periorbital and naso-ethmoidal complex, except where there was major dislocation.

[Preoperative diagnosis of complex craniofacial syndromes]. / Präoperative Diagnostik komplexer kraniofazialer Syndrome.

The aim of this study was to evaluate stereolithography as a tool in craniofacial surgery. The indications were classified according to the usefulness of stereolithography for different craniofacial pathologies. Stereolithography models of 21 patients were built; in three cases two models were made. The age of the 7 male and 14 female patients was 17 years on average (range: 15 months-44 years). First a helical volume CT scan of the anatomical region was performed. After transformation of the data set, the models were built by an SLA 250 stereolithography apparatus (3D-Systems, Valencia, Calif., USA), steered by FORM-IT/DCS-Software (University of Zurich, Switzerland). The stereolithography models were constructed by superposition of epoxy resin slices of 0.05 mm thickness, which were polymerized by a helium-cadmium laser. These models were classified according to the indication for stereolithography, the operation performed, the relevance for surgical planning and the usefulness for the fabrication of implants and protheses. In craniofacial syndromes, severe asymmetries of the viscerocranium, large skull defects and before surgical correction of hypertelorism these models provided important additional information for the surgeon. Before complex interventions in these fields the construction of a stereolithography model should be considered. In multiple fractures consolidated in dislocation, the models proved to be less useful.

[A new device for reproducible computerized tomography in improved diagnosis of surgical maxillofacial conditions]. / Ein neues Gerät für reproduzierbare Computertomographie zur verbesserten Diagnostik kieferchirurgischer pathologischer Befunde.

The aim of this study was the evaluation of a newly developed radiotranslucent headholder (craniostat) in order to improve diagnosis of maxillofacial pathology. In this prospective study, 103 patients with maxillofacial pathology were examined preoperatively with a Philips SR 7000 computed tomograph using this craniostat. The apparatus was applied fixing the patient's head at three points (meatus acusticus externus on both sides and the glabella). The control group consisted of 106 patients with similar pathology who were examined by computed tomography without a headholder. The application of the craniostat resulted in the following advantageous findings: (1) reproducible CT scans, therefore very precise assessment of the course of a disease; (2) fewer motion artifacts; and (3) symmetrical posture of the patient's head. This headholder is helpful in improving maxillofacial diagnosis by computed tomography if a symmetrical, reproducible posture of the patient's head is to be achieved and motion artifacts could otherwise make the interpretation of the resulting images much more difficult.

[Pre-operative diagnosis of complex craniofacial syndromes]. / Präoperative Diagnostik komplexer kraniofazialer Syndrome.

The aim of this study was to evaluate stereolithography as a tool in craniofacial surgery. The indications were classified according to the usefulness of stereolithography for different craniofacial pathologies. Stereolithography models of 21 patients were built; in three cases two models were made. The age of the 7 male and 14 female patients was 17 years on average (range: 15 months-44 years). First a helical volume CT scan of the anatomical region was performed. After transformation of the data set, the models were built by an SLA 250 stereolithography apparatus (3D-Systems, Valencia, Calif., USA), steered by FORM-IT/DCS-Software (University of Zurich, Switzerland). The stereolithography models were constructed by superposition of epoxy resin slices of 0.05 mm thickness, which were polymerized by a helium-cadmium laser. These models were classified according to the indication for stereolithography, the operation performed, the relevance for surgical planning and the usefulness for the fabrication of implants and protheses. In craniofacial syndromes, severe asymmetries of the viscerocranium, large skull defects and before surgical correction of hypertelorism these models provided important additional information for the surgeon. Before complex interventions in these fields the construction of a stereolithography model should be considered. In multiple fractures consolidated in dislocation, the models proved to be less useful.

[A new device for reproducible computed tomography improving diagnosis of maxillofacial pathology]. / Ein neues Gerät für reproduzierbare Computertomographie zur verbesserten Diagnostik kieferchirurgischer pathologischer Befunde.

The aim of this study was the evaluation of a newly developed radiotranslucent headholder (craniostat) in order to improve diagnosis of maxillofacial pathology. In this prospective study, 103 patients with maxillofacial pathology were examined preoperatively with a Philips SR 7000 computed tomograph using this craniostat. The apparatus was applied fixing the patient's head at three points (meatus acusticus externus on both sides and the glabella). The control group consisted of 106 patients with similar pathology who were examined by computed tomography without a headholder. The application of the craniostat resulted in the following advantageous findings: (1) reproducible CT scans, therefore very precise assessment of the course of a disease; (2) fewer motion artifacts; and (3) symmetrical posture of the patient's head. This headholder is helpful in improving maxillofacial diagnosis by computed tomography if a symmetrical, reproducible posture of the patient's head is to be achieved and motion artifacts could otherwise make the interpretation of the resulting images much more difficult.

The pterygoid hamulus as a pain-inducing factor. A report of a case and a radiographic study.

A case is reported of a patient suffering from untraceable pain in the palate. The hyperplastic pterygoid hamulus appeared to be the cause of his discomfort. A computed tomography study on 20 adult patients revealed a wide variation in the anatomy of this region, but a fairly consistent pattern in the left-right relationship in the same patient.

A new method for assessing the temporomandibular joint quantitatively by dental scan.

The objective of this study was to assess the applicability of a multiplanar reformatting program (dental scan) for delineation and quantitative evaluation of the temporomandibular joint (TMJ) in the sagittal and coronal planes using the data of axial computed tomography. The resulting images were compared with standardized linear tomograms and direct sagittal and frontal computed tomography. Standardized linear tomograms and computed tomography of the TMJ in axial, frontal and sagittal planes were obtained in 11 patients. The axial computed tomography slices were then reconstructed in oblique frontal and sagittal planes according to the horizontal condylar angle of the TMJ by dental scan software. For each patient and each of the three imaging methods, 14 measurements were undertaken and 24 qualitative characterizations were assessed. Axial computed tomograms in combination with their corresponding coronal and sagittal reconstructions were more accurate than conventional tomograms. Direct coronal and sagittal scans gave the most detailed images, but required additional radiation dose, time and cost. Reconstructions of axial computed tomography slices of the TMJ using the dental scan software show several advantages over linear tomograms. They allow qualitative as well as quantitative evaluation of the TMJ.