A novel neural network model of Earth's topside ionosphere.

The Earth's ionosphere affects the propagation of signals from the Global Navigation Satellite Systems (GNSS). Due to the non-uniform coverage of available observations and complicated dynamics of the region, developing accurate models of the ionosphere has been a long-standing challenge. Here, we present a Neural network-based model of Electron density in the Topside ionosphere (NET), which is constructed using 19 years of GNSS radio occultation data.

Filamentary field-aligned currents at the polar cap region during northward interplanetary magnetic field derived with the Swarm constellation.

ESA's Swarm constellation mission makes it possible for the first time to determine field-aligned currents (FACs) in the ionosphere uniquely. In particular at high latitudes, the dual-satellite approach can reliably detect some FAC structures which are missed by the traditional single-satellite technique. These FAC events occur preferentially poleward of the auroral oval and during times of northward interplanetary magnetic field (IMF) orientation.

Satellite observations of magnetic fields due to ocean tidal flow.

The ocean is an electrically conducting fluid that generates secondary magnetic fields as it flows through Earth's main magnetic field. Extracting ocean flow signals from remote observations has become possible with the current generation of satellites measuring Earth's magnetic field. Here, we consider the magnetic fields generated by the ocean lunar semidiurnal (M2) tide and demonstrate that magnetic fields of oceanic origin can be clearly identified in satellite observations.

[Intra-individual comparison of alpha- and beta-TCP ceramics in an animal experiment].

In the quest for bioinert adaptable alloplastic materials, TCP ceramics have gained a new application in craniofacial bone substitutes. Therefore, a histomorphological, intraindividual, comparative study was conducted on seven adult Goettingen miniature pigs (GMP) to analyze the difference of the degradation and remodelling processes of alpha-TCP and beta-TCP in critical size defects of the proximal tibiae. In addition, primary insertion of dental implants followed to study osseous integration.

[The development of modern osteosynthesis].

Within the last 30 years, rigid fixation has revolutionized a wide range of treatment procedures in cranio-maxillofacial surgery. Rigid fixation allows for a three-dimensional reconstruction of the facial skeleton. In fracture treatment and following osteotomies in orthognathic surgery, any postoperative maxillo-mandibular fixation by dental arch bars can be avoided.

The resorbable miniplate system Lactosorb in a growing cranio-osteoplasty animal model.

In the surgical treatment of craniosynostosis and craniofacial dysostosis in the growing child, passive intraosseous translocation (PIT effect) with intracranial displacement of metal plates and screws may be a problem. In an animal experiment, a possible PIT effect using resorbable PLA/PGA miniplates (Lactosorb, W. Lorenz, FL, USA) following cranio-osteoplasty were investigated in four young Göttingen minipigs.

[Biodegradable miniplates (lactosorb) in cranio-osteoplasty--experimental results with the rapidly maturing, juvenile minipig].

As a passive intracranial transmission (PIT- effect) has been described for metallic osteosyntheses materials in the infant growing skull. Thereby the use of resorbable plates and screws might be an alernative fixation device in infant craniofacial surgery. For evaluating the biological behaviour, craniotomies were performed in the frontoorbital region of four infant minipigs, six weeks of age and 6.

[Clinical studies on the pathophysiology of odontogenic abscesses].

In 26 patients with abscesses in the maxillofacial area, the electrolyte concentrations, pH and osmotic and hydrostatic pressures of the pus fluid were measured and calculated. The main cations identified were sodium (134 +/- 38 mmol/l) and potassium (37 +/- 16 mmol/l) and as anions chloride (183 +/- 46 mmol/l) and bicarbonate (10 +/- 4 mmol/l). The pH value of the pus liquid was 6.

[Results of the application of the Goettingen concept for three-dimensional repositioning of the maxilla in orthognathic surgery].

During orthodontic-surgical treatment, a three-dimensional repositioning of the maxilla is needed after Le Fort I osteotomy. The preoperatively planned and desired position of the maxilla could often not be implemented satisfactorily in the surgical procedure. Several authors described deviations of up to 15 mm in the vertical dimension and 5 mm in the sagittal dimension between the planned and the achieved position.

Techniques for achieving three-dimensional positioning of the maxilla applied in conjunction with the Göttingen concept.

Three-dimensional repositioning of the maxilla is possible after Le Fort I osteotomy. However, the preoperatively planned and desired position of the maxillary dental arch often cannot be sufficiently achieved during actual surgery, and deviations in the sagittal and vertical dimensions are common. To reduce these errors, the model-repositioning instrument was developed for model surgery in conjunction with the Göttingen concept for orthodontic-surgical treatment with condylar position control.

[Significance of periosteum in profile and contour improving osteotomies of the growing skull. Animal experiment studies with the juvenile minipig].

Passive intracranial translocation of plates and screws (PIT effect), which has been described in the literature, is one of the undesirable outcomes in infant craniofacial surgery. Therefore, we investigated the hypothesis of whether epiperiosteal placement of plates and screws causes the periosteum to act as a "limiting membrane", possibly preventing or delaying passive intracranial translocation of hardware. In two different experimental models of the fast-growing skull of juvenile minipigs (16 or 7 weeks old) on one side of the skull a typical, standard galeaperiosteal flap was raised.

Scanning electron microscopic study of primary fracture healing.

Scanning electron microscopy was used to study primary bone healing. This technique, essential for a three-dimensional description, has provided excellent visualization and revealed new aspects of the micromorphology of primary bone healing. Calcifying collagen bundles were responsible for the first mechanical stability, bone healing took place later in fracture vaults generated by compressed fracture fragments which were partially nonvital.

Hemifacial microsomia: extraoral appliance for the early treatment of an infant. Literature review and case report.

In this report a description of the different features of hemifacial microsomia is given and a new way of early treatment of concomitant respiratory problems is presented. An extraoral appliance was developed for the treatment of an infant affected with this syndrome. The purpose was to temporarily minimize the child's repeated respiratory disturbances, which were probably caused by glossoptosis, until an autologous costochondral graft in the mandibular ramus could be performed.

Results of treatment of fractures of the atrophic edentulous mandible by compression plating: a retrospective evaluation of 84 consecutive cases.

Purpose: This article introduces a simple and reproducible classification of the degree of atrophy in fractures of the atrophic edentulous mandible, and evaluates the results of treatment in 84 consecutive fractures based on this classification.

Material And Methods: Eight-four fractures of the edentulous mandible, with a height at the fracture site of < or = 20 mm, were included. Using the ratio of actual plate width to plate width on the postoperative radiograph, the actual height of the mandible at the fracture site was calculated.

The functional palatorrhaphy in the treatment of obstructive sleep apnoea.

We have developed a new operation for the surgical treatment of obstructive sleep apnoea, which we called functional palatorrhaphy. This preserves the posterior border of the soft palate and allows a controlled repair of the aponeurosis of the soft palate muscle. We combine the palatorrhaphy with a standard or a modified chin osteotomy with advancement of the base of tongue.

A stable positioning for patients requiring large calvarial exposure for surgical correction of cranial synostosis.

We present a simple and elegant method of positioning the child's head for repair of craniosynostosis. The Sugita head holder allows large exposure of the calvarium with little risk of injury, dislocation or extensive blood loss caused by venous compression. We operated upon 37 patients (age range, between 3 and 132 months, median age 7 months) and did not observe any complication or lesion caused by positioning.

[Fractures of the atrophic mandible--a challenge for therapy].

Because treatment of fractures of the atrophic mandible still today presents significant difficulties and treatment modalities remain controversial, 87 of these consecutive fractures which were treated by an uniform method as compression osteosynthesis were evaluated. A new classification of the degree of atrophy which considers the special interest of fracture treatment is introduced. It is based on a metrical measurement of the height of the mandible in the fracture area.

[Results of compression osteosynthesis with intraoral approach in 922 mandibular fractures].

A series of 922 fractures of the mandibular body (median-paramedian, horizontal ramus and mandibular angle) was treated within a 10 years period from January 1984 to December 1993 by an uniform treatment method. It consisted of compression plating with bicortical screw anchorage and intraoral approach, thus avoiding any outer scar and facial nerve damage. Postoperatively intermaxillary fixation was not used in any of these cases.

[The motivation and experiences of patients in connection with orthodontic-oral surgery combined therapy. A patient survey with consideration of the clinical and psychosocial factors].

In a retrospective study 140 patients, 97 females and 43 males who had undergone combined orthodontic surgical therapy between 1984 and 1992, were interviewed using a questionnaire. The "closed form" questions were designed to provide insight into the patients' motivations for seeking treatment and into their perceptions of its course and outcome. Nine working hypotheses taken from the literature served as the study's starting point.

Passive and active intracranial translocation of osteosynthesis plates in adolescent minipigs.

On the basis of the clinical and experimental proof that intracranial translocation of osteosynthesis plates occurs in infants after fixation on frontal bone, we conducted an animal study on four adolescent Göttingen minipigs. Our aim was to study the effects on intracranial translocation of two different types of osteosynthesis plates by comparing the plate-bone interface on the intact frontal bone treated with a multiple-point contact plate versus a conventional smooth one, paying special emphasis to the periosteum. Within a few weeks of implantation, osseous regeneration products surrounded the plate.

[The differential diagnostic value of skeletal, dental and soft-tissue analyses in the planning of orthodontic-oral surgical therapy. A retrospective study of treated patients with skeletal Angle class III].

The study evaluated the orthodontic documentation gathered in the course of conducting combined surgical-orthodontic therapy on 45 skeletal angle class III patients. In 15 of the patients Le Fort I osteotomy of the maxilla was performed, in 15 sagittal split osteotomy of the mandible, and in the last 15 patients bimaxillary surgery. The purpose of the study was to evaluate by means of a retrospective analysis of cephalograms taken prior to surgery the role hard tissue, soft tissue, and dental cephalometric variables play in the choice of the type of surgery to be performed.

[Resorbable synthetics (PDS foils) for bridging extensive orbital wall defects in an animal experiment comparison].

In a long term animal study (min 2 weeks; max 48 weeks) on 6 minipigs, clinical related defects of the medial orbital wall extending in the orbital roof (2.5 cm x 3.5 cm) were created.

[Peridural morphine administration for postoperative analgesia on the general medical unit].

With the present study the risk of postoperative peridural analgesia with morphine on ordinary wards should be estimated. 50 patients undergoing gynecological laparotomies received 3 mg morphine by a peridural catheter for postoperative pain relief. The degree of postoperative pain was objectivated by a visual analogue scoring system (1-10).

[The treatment results in the differential therapy of mouth carcinomas. A retrospective study of the patient population of the Oral Surgery Department (1978-1986) of the University of Göttingen].

In a retrospective observational study on malignomas of the oral and maxillofacial region a data material of 157 patients has been analyzed. Results of the therapy and the course of disease are presented. The average delay between the appearance of the first symptom respectively the beginning of a therapy and the treatment in a specialized department for maxillofacial surgery runs up to 4.