Stability of edentulous, atrophic mandibles after insertion of different dental implants. A biomechanical study.

OBJECTIVES: Fractures of the atrophic edentulous mandible are a rare complication that can become severe after the insertion of dental implants. This in vitro study investigated the effects of different implant settings varying in number, diameter, and length. and the influence of a fixed bar. MATERIALS AND METHODS: In biomechanical experiments on artificial mandibles, an unmodified reference group, four implant settings with two different implants, and the effect of adding a fixed bar to these settings were tested. All specimens were loaded with incisal biting forces until failure due to fracture. RESULTS: Implants weakened all specimens significantly compared with those in the reference group. Without a fixed bar, four short and thick implants showed the best results, with high significance. With a fixed bar, four long and thin implants withstood the highest loads. The addition of fixed bars reduced the differences between the implant settings. Fixed bars did not show increased stability for all groups; however, these groups showed a higher mean strength. CONCLUSIONS: Four implants with a short and thick design should be the first choice when implants are placed without a fixed bar in an atrophic mandible. With a fixed bar, four long and thin implants should be used.

The orally active melanocortin-4 receptor antagonist BL-6020/979: a promising candidate for the treatment of cancer cachexia.

BACKGROUND: Under physiological conditions, the melanocortin system is a crucial part of the complex network regulating food intake and energy expenditure. In pathological states, like cachexia, these two parameters are deregulated, i.e., food intake is decreased and energy expenditure is increased-a vicious combination leading to catabolism. Agouti-related protein (AgRP), the endogenous antagonist at the melanocortin-4 receptor (MC-4R), was found to increase food intake and to reduce energy expenditure. This qualifies MC-4R blockade as an attractive mode of action for the treatment of cachexia. Based on this rationale, a novel series of small-molecule MC-4R antagonists was designed, from which the orally active compound BL-6020/979 (formerly known as SNT207979) emerged as the first promising development candidate showing encouraging pre-clinical efficacy and safety properties which are presented here. METHODS AND RESULTS: BL-6020/979 is an orally available, selective and potent MC-4R antagonist with a drug-like profile. It increased food intake and decreased energy expenditure in healthy wild-type but not in MC-4R deficient mice. More importantly, it ameliorated cachexia-like symptoms in the murine C26 adenocarcinoma model; with an effect on body mass and body composition and on the expression of catabolic genes. Moreover, BL-6020/979 showed antidepressant-like properties in the chronic mild stress model in rats and exhibits a favorable safety profile. CONCLUSION: The properties of BL-6020/979 demonstrated in animal models and presented here make it a promising candidate suitable for further development towards a first-in-class treatment option for cachexia that potentially opens up the opportunity to treat two hallmarks of the disease, i.e., decreased food intake and increased energy expenditure, with one drug.

Qualitative and quantitative evaluation of bony structures based on DICOM dataset.

PURPOSE: The aim of this study was to investigate bone mass using different cone-beam computed tomographies (CBCTs) combined with image analysis and to determine whether bone quantity or quality was detected. MATERIALS AND METHODS: Different measurements recorded on mandible bones of pigs in the retromolar region were evaluated on ProMax 3D (Planmeca Oy, Finland) and the ILUMA™CT (IMTEC™ Imaging, Ardmore, OK) to calculate a calibration curve. The spatial relationships of pig mandible halves relative to adjacent defined anatomical structures were assessed by means of 3D visualization software. In addition to the screenshot, their bone quality was evaluated in accordance with the Lenkholm and Zarb classification. RESULTS: The CBCT calibration curves based on the measurements taken from the ProMax and ILUMA CT showed linear correlation. Huge Hounsfield units intervals were found between the 2 CBCTs and there was no correlation with the computed tomography. Exact information on the micromorphology of the bone cylinders was not available. A subjective correlation according to Lenkholm and Zarb showed overlapping in all groups. CONCLUSIONS: CBCT is a good choice for analyzing bone mass. However, it does not provide any information on bone quality. To obtain information on the microarchitecture of the spongiosa, it is necessary to use a computed tomography with finite element analysis.

Gingival angiosarcoma mimicking necrotizing gingivitis.

The authors present a case of a rare highly malignant condition that initially appeared clinically and histologically to be the relatively common and benign condition necrotizing gingivitis. Conditions that do not follow the expected clinical course mandate further investigation because rare malignant disease is not foremost in the mind of dentists and oral and maxillofacial surgeons.

New real-time PCR detects prolonged norovirus excretion in highly immunosuppressed patients and children.

Noroviruses (NoV) are a major cause of epidemic nonbacterial gastroenteritis and affect all age groups worldwide. Three of five NoV genogroups, namely, genogroup I (GI), GII, and GIV, are associated with human disease. Unfortunately, these genogroups demonstrate a high degree of sequence diversity, complicating the design of pan-NoV diagnostic PCR tests. To decrease the risk of false-negative test results, we have developed a new one-step real-time TaqMan reverse transcription-PCR protocol. This protocol detects all human NoV genogroups in one reaction with a sensitivity of 400 virus genome equivalents/reaction for both GI and GII. The use of in vitro-transcribed NoV RNA as an external standard allows (semi)quantification of viral loads in samples. In a retrospective analysis of 206 stool samples from 77 patient episodes, the duration of NoV excretion and the amount of virus excreted were determined. Twenty (26.0%) of these episodes lasted longer than 10 days. Univariate risk factor analysis revealed the patient status after organ transplantation (odds ratio [OR], 7.49 [95% confidence interval, 2.06 to 28.32]; P < 0.001), immunosuppression (OR, 9.19 [95% confidence interval, 2.50 to 35.39]; P < 0.001), and age of less than 10 years (OR, 4.58 [95% confidence interval, 1.36 to 15.77]; P = 0.004) as risk factors for a NoV excretion period of more than 10 days. These findings were confirmed by time-dependent Kaplan-Meier analyses, whereas multivariate Cox regression analyses identified immunosuppression as the sole risk factor. Surprisingly, in contrast to the excretion periods, the viral loads in stools did not increase in connection with age or immunosuppressive status. This fact may be one important piece in the pattern of high-level NoV transmissibility and may have an impact on the development of transmission prevention strategies.

Synthetic, pure-phase beta-tricalcium phosphate ceramic granules (Cerasorb) for bone regeneration in the reconstructive surgery of the jaws.

The aim of this study was to investigate the long-term effect of the ceramic beta-tricalcium phosphate (beta-TCP) at different sites of alveolar reconstruction and to evaluate its properties. From 1997 to 2002, beta-TCP was implanted as bone substitute in 152 patients using a standardized study protocol. Main indications were the filling of large mandibular cysts (n=52), secondary and tertiary alveolar cleft grafting (n=38), periodontal defects (n=24) and maxillary sinus floor augmentation (n=16). For defects exceeding 2cm in diameter, beta-TCP was combined with autologous bone taken from the retromolar area, the maxillary tuberosity or the chin region. A radiological, clinical and ultrasonographical examination was carried out 4, 12 and 52 weeks postoperative. In 16 cases, biopsies were taken after 12 months indicating complete bony regeneration. While wound-healing disturbances occurred in 9.2% of cases, partial loss of the bone substitute material was found in 5.9%, while total loss occurred in only 2%. Complete radiological replacement of beta-TCP by autologous bone was found after approximately 12 months, indicating its osteoconductive properties. Because of its versatility, low complication rate and good long-term results, synthetic, pure-phase beta-TCP is a suitable material for the filling of bone defects in the alveolar region.

[Small fragment screws vs. plate osteosynthesis in condylar head fractures]. / Kleinfragmentschrauben vs. Plattenosteosynthese bei Gelenkwalzenfrakturen. Vergleich funktioneller Ergebnisse mit MRT und Achsiographie.

AIMS: This prospective study evaluates the outcome after osteosynthesis of condylar head fractures using 1.7 mm small fragment screws (2/2000 ff), which were selected according to a previous biomechanical trial to optimize condylar head traumatology. Clinical and functional results were compared to a group of fractures fixed mainly by mini- and microplates (1993-2000) and to a control group after conservative therapy with early functional training. PATIENTS AND METHODS: Functional values (axiography and MRI) regarding loss of vertical height, disk mobility, protrusive and translatory movements were assessed (a) in 34 of 83 condylar head fractures (groups V and VI according to Spiessl and Schroll, 22/69 subjects) managed by osteosynthesis with 1.7-mm small fragment screws (KFS), (b) a reference group (43/84 subjects) fixed mainly by mini- or microplates (PLO), comprising 56 of 101 fractures (1993-2000), and (c) 16 condylar head fractures after conservative therapy with early functional training (KT) as a control. RESULTS: In cases of small fragment screws, loss of vertical height (0.3 mm) was significantly reduced (p<0.01) in comparison to PLO (1.6 mm) and KT (6.9 mm). Disk mobility in KFS reached 90% of the non-fractured sides (NFS), thus clearly superior (p<0.01) to PLO (63% of NFS) and KT (40% of NFS). Translatory movements after KFS showed better results, too (p<0.05), with mediotrusion 84% and protrusion 80% of NFS. After PLO, mediotrusion was 62%, protrusion 71% of NFS, whereas KT showed only 53% (mediotrusion) and 56% (protrusion) of NFS. High-grade limitations of translatory movements presented in about 30% after PLO and <10% in KFS (p<0.01). Fragment displacements were found in <5% after small fragment screws, and in the plate osteosynthesis group in 15% (p<0.01). CONCLUSIONS: Due to better stability and reduced articular scarification osteosynthesis with 1.7-mm small fragment screws in condylar head fractures showed clearly superior functional results compared to mini- and microplates, and to conservative therapy.

[Duodenal ileus due to an intramural duodenal haematoma. Conservative therapy using a multiple lumen intestinal probe]. / Duodenalileus bei Darmwandhämatom. Konservative Therapie mit einer mehrlumigen Intestinalsonde.

HISTORY AND ADMISSION FINDINGS: A 68-year-old woman was admitted with upper abdominal symptoms, epigastric fullness and nausea, eight days after initiation of heparin anticoagulation for deep-vein thrombosis. There were no other clinical abnormalities. INVESTIGATIONS: Abdominal ultrasound and computed tomography showed an intramural duodenal haematoma. Endoscopy revealed a stenosing lesion in the duodenum. TREATMENT AND COURSE: Instead of conventional parenteral nutrition, a triple-lumen feeding tube was placed, one lumen in the jejunum for feeding, the other for gastric decompression. Six months later the symptoms had completely disappeared and ultrasound, endoscopy and computed tomography no longer detected any lesion. CONCLUSION: Intrajejunal feeding and gastric decompression via a multi-lumen tube provided effective conservative treatment of duodenal ileus together with gastric decompression.

Limits for the central production of Theta+ and Xi(--)pentaquarks in 920-GeV pA collisions.

We have searched for Theta+(1540) and Xi(--)(1862) pentaquark candidates in proton-induced reactions on C, Ti, and W targets at midrapidity and square root of s = 41.6 GeV. In 2 x 10(8) inelastic events we find no evidence for narrow (sigma approximately 5 MeV) signals in the Theta+ --> pK0(S) and Xi(--) --> Xi- pi- channels; our 95% C.L. upper limits (UL) for the inclusive production cross section times branching fraction B dsigma/dy/(y approximately 0) are (4-16) mub/N for a Theta+ mass between 1521 and 1555 MeV, and 2.5 mub/N for the Xi(--). The UL of the yield ratio of Theta+/Lambda(1520) < (3-12)% is significantly lower than model predictions. Our UL of B Xi(--)/Xi(1530)0 < 4% is at variance with the results that have provided the first evidence for the Xi(--).

[Skin-level gastrostomy -- long-term results from a prospective trial in gastric and jejunal application]. / Button-Gastrostomie -- Langzeitergebnisse einer prospektiven Untersuchung bei gastraler und jejunaler Anwendung.

OBJECTIVE: The usefulness of skin-level gastrostomy tubes (button systems) for maintaining nutrition support after primary insertion of percutaneous endoscopic gastrostomy (PEG) is widely accepted. After first promising experiences with newly developed skin-level gastrostomy system (Freka-Button Gastrostomy) the safety and long-term stability of this new tube was not defined. MATERIAL AND METHODS: In a cohort study we prospectively evaluated from 2.1998 until 12.2001 for ease of use, complications, time to failure and long-term follow-up of 61 Freka button gastrostomies inserted in 50 patients (mean age 57.6 years, range 6 - 78 years, 44 men, 6 women). Mean time after primary PEG placement was 6.3 months (range 1 - 30 months). RESULTS: Correct application of all buttons (48 gastric, 2 jejunal) was easy and fast (median time 11 minutes) to perform. In 56 % we used a new Seldinger guide wire technique to improve stomal passage. Within the first ten days and during long-term follow-up (median 248, range 2 - 593 days) no major complication was seen. 11 systems had to be replaced mainly due to balloon failure (median 352, range 186 - 593 days). The total observation time were 15,128 days with a system failure rate of 0.26 per year. CONCLUSION: The Freka-button systems provides an easy-to-use, safe, and feasible alternative for long-term use of skin-level gastrostomy. First jejunal application of this new device was promising but needs further evaluation.

Effects of laser-modified versus osteopromotively coated titanium membranes on bone healing: a pilot study in rat mandibular defects.

Regeneration of alveolar bone with membrane techniques has become an integral part of implant dentistry. The aim of the present study was to determine if laser-modified titanium membranes are of value in the regeneration of so-called critical size defects in the rat model compared with titanium membranes that were coated with growth factors. A total of 24 rats were included in the study. Critical size defects were created bilaterally and covered by titanium membranes coated with (1). polylactide, (2). polylactide and clindamycin, (3). polylactide and growth factors, (4). polylactide, clindamycin and growth factors and (5). uncoated but laser-modified titanium membranes. All 18 control defects were covered by titanium membranes without any substrate. Four weeks after treatment the animals were killed. Laser-modified titanium membranes (group 5) showed new bone formation in many areas. Nevertheless, complete bridging was found only in one specimen. In contrast, in groups 3 and 4, most defects showed almost complete bridging of the defects. In particular, clindamycin had no inhibitory effect on bone healing. Furthermore, after 28 days, there was no significant difference between the individual groups (including controls) with respect to the total amount of lamellar bone. Growth-factor-coated membranes can significantly accelerate the healing process of bony defects in the rat mandibular model. Nevertheless, it is not possible to accelerate bone healing with laser-irradiated membranes or to enhance the quality of bone within the time period examined.

[Tube feeding - who, how and when]. / Sondenernährung - Wer, Wie, Wann?

Summary. The concept of enteral nutrition is well established for a long time. During the past twenty years different percutaneous tube feeding techniques have been established. The most popular method is the percutaneous endoscopic gastrostomy (PEG) which is applied as a pull-through technique in Germany. In some patients this approach is not successful and alternative techniques must be used (e. g. introducer method). In some patients nasal or percutaneous feeding tube have to be placed directly into the intestine. There are different systems available for this approach which have to be clearly indicated. As a second step after initiation of enteral nutrition therapy quality of life can be improved by implanting secondary systems (e. g. button gastrostomy).A standardized technique for inserting tubes is essential to have a successful long-term outcome in enteral nutrition and care after has to be integrated into the regimen. The aim of this article is to demonstrate different enteral nutrition tube techniques their indication, contraindication and long-term follow-up.

Peri-implant care of ailing implants with the carbon dioxide laser.

One of the many applications for which lasers have been proposed in implant dentistry is for the decontamination process. The purposes of this study were to assess possible alterations in titanium implants in vitro and in vivo by use of the carbon dioxide (CO2) laser and to determine whether new bone formation can occur on previously contaminated implants. In vitro, temperature changes at the bone-titanium implant interface were recorded during use of a CO2 laser-scanning system (Swiftlase). Additionally, the effects of laser irradiation on titanium implants at various power settings were examined. In 6 beagle dogs, a total of 60 implants and bony defects resulting from plaque accumulation were treated by air-powder abrasive (the conventional treatment), laser irradiation, or both. Depending on the parameters chosen, melting and other surface alterations were seen in vitro, especially in the superpulse mode. Otherwise, no alterations were found, even at high power settings in the continuous mode. In vivo, corresponding histologic examination of 4-month sections showed evidence of new direct bone-to-implant contact after laser-assisted therapy, especially when the implants had been treated concomitantly with submerged membranes. These results support the hypothesis that peri-implant defects can be treated successfully by laser decontamination without damaging the surrounding tissues in the dog model. Nevertheless, further investigations will be required to determine the clinical efficacy of the treatment.

[Ulcerative esophagitis and colitis as rare manifestations of Adamantiades-Behcet disease]. / Ulzeröse Osophagitis und Kolitis als seltene Manifestationen bei Morbus Adamantiades-Behçet.

We report the case of a 39-year-old German women who suffered from chronic inflammatory bowel disease which had not been exactly classified for 6 years. In the course of the disease she developed recurrent iritis, nodular skleritis, oral and genital ulcer, erythema nodosum and axillary folliculitis. For the first time retrosternal pain occurred. Endoscopy of the upper gastrointestinal tract showed mid esophageal ulcer formation. Colonoscopy demonstrated ulcerative colitis with no involvement of rectal mucosa. Histologically a cutaneous vasculitis in the lower limb was seen and diagnosis of Adamantiades-Behçet disease with marked gastrointestinal involvement and rare manifestation in the esophagus was established. A therapy with prednisolone, azathioprine and mesalazine was started. Under this regimen stomatitis, esophagitis and cutaneous vasculitis resolved, while the colitis showed partial remission now for up to one year.

Self-expanding metallic stents for continuous dilatation of benign stenoses in gastrointestinal tract - first results of long-term follow-up in interim stent application in pyloric and colonic obstructions.

The use of self-expandable metallic stents (SEMS) is an established palliative treatment of malignant stenosis in the gastrointestinal tract. There is wide experience with the palliation of malignant esophageal obstruction and fistulae, but the application of stents in benign stenosis is rarely reported and exclusively deals with obstruction of the esophagus. No data has been available for benign gastric outlet and rectosigmoid obstruction until now. For the first time we report about 4 cases, in which we temporarily implanted a SEMS (Ultraflex(R) stent, Boston Scientific Microvasive(R)) in benign stenosis of the pylorus or rectosigmoid between 09.97-07.98. The indications for stent implantation were failure of established dilatation therapy and/or refusal of surgical treatment, and/or surgical high-risk patients. Our idea was to prolong the duration of the dilatation by interim implantation (range 8 days - 12 weeks) of a SEMS. There where no peri-interventional complications or dislocations. In one case endoscopic removal was not possible, peranal surgical approach allowed the removal of the stent. During follow-up (range 34-39 months) 2 patients needed one bougienage directly after stent removal. Endoscopic examinations showed no recurrence of any stenosis in all patients. We conclude that interim application of SEMS in benign stenosis of the gastrointestinal tract may be a possible therapeutic tool in selected patients. Further trials with greater numbers of patients dealing with the questions of duration of stay of SEMS and choice of stent type are needed.

Modified percutaneous endoscopic gastrostomy (PEG) with gastropexy--early experience with a new introducer technique.

OBJECTIVE: The Cliny PEG 13 has been available since 1999 for clinical use in the modified introducer technique in combination with endoscopically controlled gastropexy. Data on indication, insertion technique and safety have not yet been reported in the literature. METHODS: During the time period from January 1999 to June 2000, from a total of 457 patients receiving a PEG 27 (5.9%) subjects, in whom the insertion of a PEG by means of pull-through technique was impossible or only in combination with an intervention e.g. bougienage were included in this prospective study. Each patient received a Cliny PEG 13 by means of introducer technique with endoscopically controlled double gastropexy. Tumor patients with severe stenosis made up more than 90% of the cases. The insertion and 30 day follow-up were performed using a standardized protocol. Method-related and unrelated complications were recorded. RESULTS: PEG insertion was successful in all patients without additional intervention. We did not see any method-related complications. The peri-interventional local infection rate was 3.7%. One patient died during the 30-day follow-up period as a result of progression of the underlying disease. No further complications occurred in long term follow-up. CONCLUSIONS: Our results show that the Cliny PEG 13 is a safe technique and an alternative to other methods and surgical procedures in patients in whom a PEG was not applicable by means of the pull-through technique. Larger case numbers and the use in other patient collectives will have to prove these initial results.