Transient finite element analysis of a traumatic fracture of the zygomatic bone caused by a head collision.

Midfacial fractures rank first concerning maxillofacial traumatology. Collisions of two heads or head to object are the main causes for these fractures. An investigation based on a transient simulation using the finite element method was performed. A biomechanical head model was created and tested. A transient collision of two heads was simulated. The results were compared to a typical real patient case. This comparison revealed an identical fracture pattern, which can be interpreted as a clinical match of the simulation. The results of this study show the validity of biomechanical investigations, which may serve as a method to better understand maxillofacial fracture patterns. These results will be used for the optimization of fracture therapy or trauma prevention in the future.

Differences and similarities of cytomegalovirus and pneumocystis pneumonia in HIV-negative immunocompromised patients thin section CT morphology in the early phase of the disease.

The purpose of this study was to assess CT morphology of pneumocystis pneumonia (PcP) and cytomegalovirus (CMV) pneumonia for specific characteristic features, similarities as well as differences, which might contribute to an early diagnosis and, therefore, influence patient management 58 patients were included, 31 with CMV pneumonia and 27 with PcP. All patients with CMV pneumonia had underlying haematological malignancies (n = 31) mainly treated by haematopoietic cell transplantation (HCT) (n = 26). Patients with PcP had haematological malignancies (n = 17) treated by HCT in 6, solid tumours (n = 5) and corticosteroid therapy (n = 5). Thin section CTs were analysed retrospectively by two radiologists. 18 CT morphological criteria were evaluated for presence or absence. Significance was calculated by chi2 test. Interobserver correlation was tested by kappa-statistic (K) Only 5 of the 18 features were found to have significantly different frequencies in the two entities. Apical distribution (p<0.01), mosaic pattern (p<0.01) and homogeneous structure of ground-glass opacities (GGO) (p<0.05) were found more frequently in PcP (each K: 0.7-0.9), whereas small nodules or unsharp demarcation of GGO and consolidation were typical of CMV pneumonia (p<0.05). Peripheral sparing, consolidation and septal thickening inter alia were found equally in both groups In conclusion analysis of craniocaudal distribution, demarcation and structure of infiltrates may be helpful in prioritizing differential diagnosis of CMV pneumonia or PcP. However, some features thought typical for one or the other entities appear with similar frequency in both groups in HIV-negative patients.

[Functional and aesthetic outcome of nasal surgery in cleft lip palate patients]. / Funktionelle und ästhetische Ergebnisse von Nasenkorrekturen bei Patienten mit Lippen-Kiefer-Gaumen-Spalten.

Between June 1996 and November 2000 60 patients suffering from severe nasal dysplasia due to cleft lip and palate (CLP) underwent corrective nasal surgery. Diagnoses included 37 cases of unilateral CLP and 23 cases of bilateral CLP. Age ranged from 7 to 50 years. To assess functional outcome three different methods were used pre- and postoperatively with and without nasal decongestion: active anterior rhinomanometry, rhinoresistometry, and acoustic rhinometry. For the measurement of esthetic changes frontal, lateral, and caudal photographs were analyzed. Compared to a non-cleft population esthetic and functional impairment was evident preoperatively. Postoperatively a statistically significant improvement in nasal projection and configuration was seen. Concerning nasal respiration an improvement in nasal flow and hydraulic diameter was noted in the unilateral CLP group only, whereas a statistically nonsignificant average deterioration was found in the bilateral CLP group. No correlation existed between external nasal form or the change in nasal appearance and nasal function. Whereas the esthetic outcome of nasal surgery is covered by way of photo-analysis in many centers, a distinct lack of measuring the effects on nasal function can be stated. Without using objective methods, however, no data for improving surgical procedures and for internal quality control are at hand.

[Distraction osteogenesis in the treatment of severe midfacial hypoplasia]. / Therapie ausgeprägter Mittelgesichtsrüklagen mit Hilfe der Distraktionsosteogenese.

PATIENTS: Between May 1998 and May 2002, 38 patients suffering from severe midfacial retrusion and atrophy were treated by way of midfacial distraction osteogenesis. Diagnoses included cleft lip and palate (32 patients) and one case of Crouzon's disease. Ages ranged from 6-65 years. A total of 28 patients presented a velopharyngeal flap and nine patients were almost or fully edentulous. Using an extraoral halo device, distraction was performed after a subtotal Le Fort-I/II/III or modified quadrangular osteotomy. RESULTS: Distraction ranged from 9 to 31 mm (17 mm average). Following the primary operation, seven patients underwent a second intervention due to problems with the procedure or the device. Two patients needed a secondary Le Fort-I-osteotomy. With respect to velopharyngeal insufficiency, 21% showed a deterioration and 8% an improvement. Postoperatively, a decrease of 15-20% in the attained sagittal advancement was seen during the first 6 months. This was attributed to relapses and postoperative orthodontics. Thereafter skeletal stability was maintained. CONCLUSION: Distraction osteogenesis of the midface can be the method of choice in severe midfacial retrusion. Due to the difficult patient situation and the technical intricacies a higher complication rate has to be accepted than for conventional dysgnathia operations.

The generation of oxygen radicals after drinking of oxygenated water.

UNLABELLED: It has been speculated whether ingestion of oxygenated water can lead to an enhanced generation of oxygen radicals. The purpose of three prospective randomized blinded clinical studies was therefore to measure if, when and at which oxygen content in the water,drinking of oxygenated water induces the generation of radicals. Moreover in the fourth prospective,randomized, blinded study possible longterm effects of drinking oxygenated water were examined. METHODS: Altogether 66 volunteers were drinking 300 ml oxygenated or tap water within 15 minutes. Before drinking, altogether 15 ml of blood from the antecubital vein was collected for determination of ascorbyl radicals with ESR, routine laboratory data (hemoglobin, erythrocytes, hematocrit, leukocytes, thrombocytes, uric acid) and the vitamins A,C,E by HPLC. After drinking the ascorbyl radical measurements were repeated from blood of the antecubital vein. In the longterm study ( fourth study) the volunteers had to undergo the same procedure, as described above, at day 1 and day 21. In the meantime they were drinking per day three times 300 ml either oxygenated water or tap water. RESULTS: All subjects exhibited normal vitamin levels in all three studies. Concommitantly in the fourth study there was no statistically relevant alteration of vitamin concentrations during the observation period of three weeks in the verum and placebo-group. 30 minutes after drinking oxygenated water the concentration of ascorbyl radicals increased significantly by median 42 % from median 48 to 65 nmol/l. This increase of ascorbyl radicals after 30 minutes was reproducible in all studies. The levels of ascorbyl radicals remained elevated for 60 minutes after drinking and returned to normal after 120 minutes. This increase was independent of the oxygen concentration in the water, beginning at 30 mg oxygen/l. Water containing 15 mg oxygen/l did not lead to an enhanced radical formation. Longterm consumption of oxygenated water attenuated the ascorbyl radical increase normally observed, thus the initial increase of ascorbyl radicals at day 1 could not be observed after day 21, if the subjects were drinking oxygenated water regularly during the observation period. CONCLUSION: Drinking of oxygenated water possibly leads to a time-limited, yet very moderate, systemic generation of radicals. Regular consumption of oxygenated water over a longer period of time seems to attenuate this effect. The mechanisms leading to this effect and adaptation are unknown.

Endoscopically assisted intraoral mandibular distraction osteogenesis.

Correct placement of intraoral devices for mandibular distraction osteogenesis is important to achieve the ideal vector of distraction. As visual inspection and intraoperative management in the inferior mandibular border or at the posterior ascending ramus is impaired, an endoscopically assisted method is presented. Since the introduction of this new technique operation time and ease have been significantly improved.

A novel modular retention system for midfacial distraction osteogenesis.

Distraction osteogenesis of the midface offers new possibilities for the treatment of large sagittal discrepancies between the upper and lower jaws. The use of an extraoral halo-borne distractor, which allows free three-dimensional vector control, may cause problems in the connection between the midface and the distractor. To overcome these difficulties, we present a new modular retention system to gain bone anchorage whenever a toothborne appliance is not suitable. Distraction osteogenesis with an extraoral appliance is therefore possible even in edentulous elderly patients. We have used this system successfully in 11 patients.

[Callus distraction of the mid-face in severe mid-face hypoplasia]. / Kallusdistraktion des Mittelgesichts bei ausgeprägter Mittelgesichtshypoplasie.

Callus distraction in the treatment of severe midfacial hypoplasia/atrophy may offer new therapeutical possibilities. Between May 1998 and March 1999, six patients underwent a subtotal Le Fort I-II osteotomy with subsequent distraction via a haloborne distractor (RED). Five patients suffered from CLP, four patients were totally or almost edentulous in the upper jaw. Corrections of sagittal discrepancies were possible in all cases (distraction 16-31 mm). No case of increased velopharyngeal insufficiency was seen. In one patient the halo had to be refixed. Three patients suffered from tension-like pain in the soft palate during distraction. Follow-up studies suggest the necessity for overcorrection of 20% in edentulous senior patients. Callus midfacial distraction is a promising new alternative to conventional orthognathic surgery in severe cases.

Impact of short-time nasal intubation on postoperative respiration.

Until now few data on postoperative nasal respiration after nasal intubation is known which is of special importance for surgery, where postoperative intermaxillary fixation is necessary. This study was planned to acquire information about nasal breathing during the first postoperative week. Twelve patients treated for mandibular retrognathism were examined repeatedly by way of anterior active rhinometry, acoustic rhinometry, and rhinoresistometry before and after surgery over one week. In addition the subjective evaluation was checked on a visual analogue scale. Following intubation, significant changes in "objective" and subjective measurements of nasal respiration could be noted only on the second postoperative day. Comparing rhinomanometric and subjective data, a correlation could be found on postoperative day two only. In this study group short-time nasal intubation had no significant impact on postoperative respiration.

[Hypercalcemia caused by generalized sarcoidosis]. / Hyperkalzämie durch generalisierte Sarkoidose.

HISTORY AND ADMISSION FINDINGS: A 70-year-old man with a 23-year history of recurrent nephrolithiasis was admitted for evaluation of hypercalcaemia (maximal calcium concentration 3.24 mmol/l). Physical examination on admission was unremarkable except for sensory neuropathy in the right foot. INVESTIGATIONS: Chest radiogram, subsequent transbronchial lung biopsy, gallium scintigraphy and magnetic resonance imaging (MRI) of the vertebrae indicated generalized sarcoidosis, predominantly affecting the mediastinum, lumbar vertebrae and nerves of the distal limbs. Parathormone level was reduced, while the levels of vitamin D metabolites were normal. TREATMENT AND COURSE: Serum calcium level became normal within 2 weeks of starting glucocorticoid treatment. CONCLUSION: Hypercalcaemia can occur in the course of sarcoidosis even in the absence of a elderly increased level of 1,25-dihydroxyvitamin D3. In this case the cause of the hypercalcaemia of a year's duration may have been due to lymphomacrophagocytic infiltration of the bone of several vertebrae as demonstrated by MRI of the vertebral columns but not by conventional radiography. In this case an increase in cytokine secretion by macrophages may have played an important role in addition to the level of 1,25-dihydroxyvitamin D3 at the upper limit of normal that, in view of the renal failure, could only have been caused by extrarenal production. Cytokines (e.g. interleukin-1 beta and tumour necrosis factor alpha) secreted by activated macrophages are among the most powerful stimulators of bone reabsorption.

Callus distraction of the midface in the severely atrophied maxilla--a case report.

OBJECTIVE: This report introduces the possibilities of callus distraction in the extremely atrophied, edentulous midface in a cleft lip and palate patient. INTERVENTION: After a subtotal Le Fort II osteotomy, tension wires were fixed to the zygomatic buttresses and frontal sinus walls by way of titanium miniplates and mesh and connected to a rigid external distractor. Then distraction of the whole midface (1 mm/d) was performed. RESULTS: Even in severe atrophy a distraction of the maxilla of 20 mm was possible. Stability has been shown for more than 5 months. CONCLUSIONS: Rigid external midfacial distraction may be used in difficult cases for the correction of sagittal discrepancies where conventional orthognathic surgery is likely to be insufficient. Further investigations will concentrate on the long-term outcome.

[Osteo-anabolic estrogen therapy in a transsexual man]. / Osteoanabole Ostrogentherapie bei einem transsexuellen Mann.

HISTORY AND ADMISSION FINDINGS: A 31-year-old man presented at the endocrinology out-patient clinic for the initiation of sex-change treatment. His manifestly transsexual male-to-female appearance was confirmed by a psychiatric-sexological expert report. The patient had been living as a woman for one year. Physical examination showed normal male physique with typical secondary hair growth and normal male genitals. INVESTIGATIONS: The serum testosterone level was at the upper limits of normal, that for oestrogen at the lower limit. Bone densitometry showed bone density at the upper limit of normal. Other laboratory tests were unremarkable. DIAGNOSIS, TREATMENT AND COURSE: During 30 months on cyproterone, 100 mg daily, bone mass fell at the rate of 5% per year. Bone biopsy revealed high turnover osteoporosis. Bone mass rose by 4% per year after the additional oral intake of oestradiol valerate, 2 mg daily. Osteoblastic cells, isolated from part of the biopsy tissue, with the patient's consent, was found to be stimulated by oestradiol in vitro. CONCLUSION: The described bone mass changes indicate the important role played by sex hormones in the maintenance of bone mass acquired during adolescence. The findings confirm that in males not only testosterone but also oestrogens has an anabolic effect on bone.

[Callus distraction of the midface. Requirements for diagnostic imaging]. / Kallusdistraktion des Mittelgesichts. Anforderungen an die bildgebende Diagnostik.

Callus distraction of the midface is a recently developed surgical method for treatment of atrophic or hypoplastic maxillae. The treatment planning is based on individual shaped models, being constructed with the help of computed tomographic data. Our experience is based on 10 patients (3 male/7 female; age: 11-55 years). The demands for imaging are reported. The following imaging procedure is recommended: 1. preoperative: lateral x-ray, orthopantomogram, spiral CT, 2. during the time of callus distraction with normaly takes 4 to 5 weeks: lateral x-ray (every 10 days), and 3. for follow up: lateral x-ray and spiral CT. The Radiation exposure caused by the repetitive images is calculated in detail.

Regulation of interleukin-6 expression in human osteoblastic cells in vitro.

Interleukin-6 (IL-6) is a potent stimulator of bone resorption which has been demonstrated in a variety of in vivo and in vitro models. We investigated the regulation of IL-6 secretion in primary human osteoblastic cells (HOC) in vitro by cytokines known to play an important role in coupling bone formation to bone resorption. HOC were isolated from healthy adults who underwent selective orthopedic surgery and treated with cytokines released in the bone microenvironment during coupling i.e Interleukin-1beta (IL-1beta), Tumor Necrosis Factor alpha (TNFalpha), Transforming Growth Factor beta1 and 2 (TGFbeta 1 and 2) and Endothelin-1 (ET-1). Furthermore, we determined whether systemically-acting steroid hormones of gonadal and adrenal origin as well as glucocorticoids affect the local regulation of IL-6 secretion in primary HOC. To examine the effects of different steroid hormones on IL-6 production, HOC were exposed to estradiol (E2), dihydrotestosterone (DHT), dehydroepiandrosterone (DHEA) and dexamethasone (Dexa) with and without a subsequent treatment of the HOC populations with cytokines. We observed that (1) IL-1beta and TNFalpha induced IL-6 in a dose and time-dependent fashion, (2) TGFbeta 1 and 2 enhanced basal and IL-1beta and TNFalpha induced IL-6 expression, (3) ET-1 elicited a dose-dependent stimulatory effect on IL-6 expression. (4) E2, DHT and DHEA alone and in combination with IL-1beta and TNFalpha elicited no reproducible dose-dependent effect on IL-6 production, whereas Dexa inhibited basal and IL-1beta and TNFalpha induced IL-6 expression dose dependently. In conclusion, IL-1beta, TNFalpha, TGFbeta 1 and 2 and ET-1 may participate in the regulation of bone resorption by stimulating IL-6 expression in HOC. Dexa inhibits the constitutive and cytokine stimulated IL-6 expression, whereas there is no in vitro evidence that sex steroids exert a major inhibitory effect on the osteoblastic secretion of IL-6 as demonstrated in a primary human bone cell model.