Biomedical subjects

Wilfried Wagner

Publications and source records attributed to Wilfried Wagner.

14 recordsLinked to original sources

PubMed2006

Third molar complications requiring hospitalization.

OBJECTIVE: The aim of this study was to describe demographic and clinical patterns of subjects hospitalized with complications associated with third molars (M3). STUDY DESIGN: The investigation was designed as a prospective cohort study composed of subjects admitted to hospital for management of M3-associated complications. The predictor variable was "clinical status of the M3" defined as (A) prophylactic M3 removal, (B) nonelective M3 removal, or (C) M3 present at the time of admission. Outcome variables were infection parameters, treatment costs, length of hospital stay, and days of disability. Postoperative complications (A and B) were compared to complications based on pericoronitis (C). Complications due to prophylactic removal (A) were compared to those arising from pericoronitis or from the removal of symptomatic teeth (B and C). RESULTS: From January 2003 to December 2004, 45 deep space infections, 6 mandibular fractures, 2 lingual nerve injuries, 1 parapharyngeal tooth luxation, and 1 osteomyelitis were noticed. Fifteen complications resulted from prophylactic surgery (A), 25 from nonelective removal (B), and 15 from pericoronitis (C). Direct treatment costs were 147,000 euro (A: 42,000 euro; B: 74,000 euro; C: 31,000 euro). In 10 of the 15 patients of group C, deep space involvement resulted immediately from the first episode of pericoronitis. Neither clinical markers of infection nor economic parameters showed significant differences between the groups. CONCLUSION: Within the catchment area of our institution, the majority of third molar-related hospitalizations resulted from diseased third molars or their removal.

Adolescent↗

PubMed2005

Clinical and prognostic value of [(18)F]FDG-PET for surveillance of oral squamous cell carcinoma after surgical salvage therapy.

[(18)F]FDG-PET was found to be useful for recurrence detection in patients with oral squamous cell carcinoma (OSCC), as a negative PET scan predicted a favorable outcome and survival. Here, we evaluate PET performance in the management of OSCC patients with recurrent/second primary disease after potentially curative second-line therapy. Forty one OSCC patients underwent salvage surgery and 31/41 had received radiation therapy. Thirty five/41 developed recurrent and 6/41 second primary OSCC. Patients had PET evaluation 8.4months (median) after surgery and were followed for at least 6months until disease recurrence or death. For surviving patients, the median follow-up was 33.6months after PET. In OSCC patients who had undergone potentially curative second-line therapy, PET had an overall sensitivity of 85% (92% for recurrence or second primaries, 88% for lymph node failure and 73% for distant metastases). Overall survival was 71% in the PET negative group and 35% in the PET positive group (p<0.01, log-rank test). Moderate glucose metabolism (standardized uptake value4) suggested promising outcome, while SUV>4 indicated a fatal disease course. The data suggest that [(18)F]FDG-PET can facilitate re-staging and clinical management in "high-risk" patients with OSCC.

Adult↗

PubMed2005

Reconstruction of mandibular defects following tumor ablation by vertical distraction osteogenesis using intraosseous distraction devices.

OBJECTIVES: Distraction osteogenesis has recently evolved a challenging technique to overcome major drawbacks of conventional augmentation procedures. We, therefore, report the application of miniaturized intraosseous distraction devices for the rehabilitation of mandibular defects due to ablative tumor surgery. METHODS: In 10 patients who had undergone box-shaped or segmental resections, augmentation of the residual mandibular bone or of full thickness iliac crest grafts was performed by intraosseous implant-shaped distractors. Distraction and reconsolidation was monitored by ultrasonography. Implants were inserted within 1 week after active distraction. Median follow-up after implant insertion was 38 months. RESULTS: On average, a vertical gain of 7.3 mm was obtained by distraction. Except for one case (local infection), all distraction zones showed complete ossification by radiologic and ultrasonographic evaluation. Overall 28 implants were placed in the distracted bone. Two implants were lost at 2.4 and 22 months after placement. The estimated 4-year implant survival rate in this population was 90%. For the endpoint 'bone loss' (>1.5 mm in the first and >1 mm in following years), the estimated 4-year success rate was 59% with four out of seven events occurring in a single patient (patient No. 1 of this series). CONCLUSION: Vertical distraction by means of implant distractors could be performed with reasonable success in tumor patients with box-shaped resection defects or undercontoured bone grafts. Overall morbidity was very low. Even though blood supply is continuously maintained in distraction osteogenesis, bone resorption remains a critical issue for this reconstruction technique too.

Adult↗

PubMed2004

[Wisdom teeth-complications requiring in-patient treatment. A 1-year prospective study].

BACKGROUND: In view of the conflicting guidelines issued by national and international scientific societies, debate about the indications for prophylactic extraction of wisdom teeth is ongoing. This prospective study was therefore set up to explore the complications associated with wisdom teeth and requiring in-patient treatment. PATIENTS AND METHODS: From January /2003 to December 2003, 21 subjects were admitted for treatment of complications associated with wisdom teeth. The medical history was recorded for each of these patients, as were the cause and type of the complications. The parameter used to quantify the severity of any infections was the CRP, and the overall clinical complexity level of each case was assessed by the length of stay in hospital (and the duration of intensive care if this had been necessary). The characteristics of patients in the group with postoperative complications were compared to those of patients with complications attributable to pericoronitis. Moreover, complications in patients who had undergone prophylactic extraction of wisdom teeth that had not been causing any symptoms were compared with those in patients whose wisdom teeth had been extracted because of morbidity. RESULTS: Overall, 18 deep-space infections (15 abscesses, 2 inflammatory infiltrations, 1 case of phlegmonous cellulitis), 2 mandibular fractures and 1 lingual nerve injury were noted within 1 year. The complications resulted from surgical procedures in 15 of the 21 cases, while in 6 they had their origin in pericoronitis. Extensive surgery or intensive care was required only for patients with postoperative complications. The length of stay in hospital was significantly greater for patients with postoperative complications ( p= 0.007, U-test). However, 9 of these 15 patients reported preoperative episodes of infection. Thus, more than two thirds of the complications could be traced back to wisdom teeth that were causing symptoms. CONCLUSION: In our clinic's catchment area, infectious complications were more frequent and more severe and required more intensive and longer treatment in hospital than complications arising from pericoronitis. However, complications of prophylactic extraction of wisdom teeth were decidedly less frequent than direct or indirect complications of extraction of symptomatic teeth. Thus, our data tend to support the concept of elective extraction of wisdom teeth with the aim of preventing serious infections.

Adolescent↗

PubMed2004

Ameloblastic fibrosarcoma or odontogenic carcinosarcoma: a matter of classification?

A biphasic odontogenic tumor with aggressive clinical behaviour is reported. The tumor arose posterior to the right mandibular third molar involving the angle of the mandible and the ascending ramus. Within a 5 years period the patient suffered from two episodes of local progression and final disease generalization occurred 6 years after initial surgical therapy. On histopathologic evaluation, both recurrences and the distant metastasis preserved the biphasic pattern seen in the primary tumor with both epithelial and mesenchymal components exhibiting clear cytological features of malignancy. There was no evidence of sarcomatous overgrowth within the progression of the tumor. By contrast, the proportion of the epithelial component was even enlarged in the second recurrence. Thus, both pathologic features and clinical behaviour clearly distinguishes this tumor from ameloblastic fibrosarcoma and demonstrates the clear morphological as well as clinical characteristics of a true malignant mixed type tumor with a definite sarcomatous and carcinomatous component. Thus, even though a very rare lesion, our case supports the consideration of the odontogenic carcinosarcoma as an individual entity.

Carcinosarcoma↗

PubMed2004

Surveillance of basaloid oral squamous cell carcinoma: the value of [18F]FDG-PET.

Basaloid squamous cell carcinoma (BSCC) represents a rare but exceptionally aggressive variant of oral cancer. Hence, when tumors have been characterized to belong to this specific high-risk subpopulation, it remains an open issue how to manage the patients in terms of diagnostic surveillance and reconstruction. Therefore we explored whether glucose metabolism as measured by [18F]FDG-PET can accurately assess the disease status in the follow up of oral BSCC. The data of four patients with pathologically proven BSCC were analyzed in this study. These patients had [18F]FDG-PET scans after curative therapy to screen for local recurrence or disease generalization. The [18F]FDG-PET findings were correlated with clinical outcome. [18F]FDG-PET identified a site of recurrent tumor that was invisible to morphological imaging. None of the three patients with a normalized pattern of glucose uptake had secondary tumor progress within the further follow up period. Thus, [18F]FDG-PET proved valuable to identify those patients who will profit from early onset of reconstruction measures even though they originally belonged to a high-risk population.

Adult↗

PubMed2003

Detection of recurrent oral squamous cell carcinoma by [18F]-2-fluorodeoxyglucose-positron emission tomography: implications for prognosis and patient management.

BACKGROUND: Patients with recurrent oral squamous cell carcinoma (OSCC) have a dismal prognosis and represent a therapeutic challenge. A positron emission tomography (PET) scan with [(18)F]-2-fluorodeoxyglucose ([(18)F]FDG) can improve early cancer detection. The current study evaluates the prognostic value of [(18)F]FDG-PET scan in patients with recurrent OSCC. METHODS: The authors studied 97 patients with previously resected OSCC who were restaged by PET scanning. Of the 97 patients, 64 had no evidence of clinical disease and 33 were suspected of having disease by imaging, clinical findings, or pathologic evaluation. The median follow-up period was 35.4 months after a PET scan. The end points included disease recurrence, a disease recurrence-free period 6 months after a PET scan, or death. RESULTS: The overall sensitivity of a PET scan did not exceed 90% and its specificity varied from 67% for local disease recurrence/second primaries to 99% for lymph node metastasis. Increased [(18)F]FDG uptake predicted increased hazard of death (hazard ratio: 6.83; P = 0.00034) and proved to be a highly predictive marker of disease status. A significant association was established for incremental standardized uptake values and 3-year patient survival (P=0.0089), indicating that intense glucose metabolism in the tumor is a negative marker of survival in recurrent OSCC. Overall, survival was longer in patients with a negative rather than a positive PET scan (P < 0.00001). CONCLUSIONS: PET scanning was found to be highly valuable for diagnosing OSCC recurrence in a postoperative setting. It provided prognostic information and played an important role in patient counseling and management.

Adult↗

PubMed2003

Overexpression of Glut-1 and increased glucose metabolism in tumors are associated with a poor prognosis in patients with oral squamous cell carcinoma.

BACKGROUND: The overexpression of glucose transporters, especially of Glut-1, is a common characteristic of human malignancies, including head and neck carcinoma. Recently, the assessment of glucose metabolism in the tumor with [(18)F]-2-fluoro-2 deoxy-D-glucose (FDG) and positron emission tomography (FDG-PET) has been used to identify particularly aggressive tumors. The authors tested the hypothesis that both glucose transport and its metabolism play a key role in the progression of oral squamous cell carcinoma (OSCC). METHODS: Retrospective analysis of Glut-1 expression was performed by immunohistology in 118 patients with OSCC, and a Glut-1 labeling index (LI) was established for each. A separate group of 44 patients with primary OSCC was evaluated prospectively by FDG-PET prior to surgery. To link the expression of Glut-1 with glucose metabolism, both FDG-PET and immunohistology were determined in a subgroup of 31 patients, and the results were correlated with overall survival. RESULTS: The patients who had OSCC with a low LI for Glut-1 survived significantly longer compared with patients who had OSCC with a high LI (138 months vs. 60 months; P = 0.0034). It was found that Glut-1 expression was an independent marker of prognosis in patients with OSCC. In patients who were evaluated by FDG-PET, the standardized uptake value (SUV) below the median split value of 5.6 was predictive of a longer survival (P < 0.027), whereas an SUV > 5.6 was associated with an increased hazard of death. In combination, a high Glut-1 level and a high SUV predicted shorter survival (P < 0.005) for patients with OSCC. Patients who achieved a complete response to preoperative radiation tended to have tumors with low glucose metabolism, as defined by both the Glut-1 LI and the SUV. CONCLUSIONS: Both glucose transport and glucose metabolism determine the glycolytic tumor phenotype, which is a significant negative biomarker of prognosis and overall survival in patients with OSCC.

Carcinoma, Squamous Cell↗

PubMed2003

Radiation response non-invasively imaged by [18F]FDG-PET predicts local tumor control and survival in advanced oral squamous cell carcinoma.

It is a major challenge to preoperatively identify patients who will profit from surgery of advanced oral cancer. In multimodality therapy, response to neoadjuvant radiation correlates to treatment success. Hence, for preoperative decisions, assessment of treatment response is required. Therefore, we analysed the prognostic significance of glucose metabolism after preoperative radiotherapy. [(18)F]FDG-PET investigations were performed for re-staging 35 patients after neoadjuvant radiotherapy (36Gy) immediately prior to tumor resection. Emission and transmission measurements were obtained and SUV's were calculated for the sites of maximum [(18)F]FDG-uptake. Subpopulations of "low" (SUV < 4) and "high" (SUV > or = 4) glucose metabolism were compared by univariate and multivariate survival analysis. 3-years survival was 80% in the "low" SUV group and 43% in the "high" SUV group. Post-irradiation [(18)F]FDG-uptake significantly predicts survival (P = 0.046) and local tumor control (P = 0.0017). High [(18)F]FDG-uptake was associated with an increased hazard of death (P = 0.037) and especially of local progress (P = 0.011) even when radical resection was performed. Thus, [(18)F]FDG-PET non invasively identified patients with poor prognosis whose indication for radical surgery has to be considered with caution.

Adult↗

PubMed2003

Comparison of platelet, leukocyte, and growth factor levels in point-of-care platelet-enriched plasma, prepared using a modified Curasan kit, with preparations received from a local blood bank.

The potential use of autologous thrombocytic growth factors to accelerate bone regeneration requires improved methods of isolating platelet-rich plasma (PRP). In addition to discontinuous cell separation, a second method by which PRP is produced at the point-of-care has now become available. In this study, growth factor levels in PRP from these two sources were compared. Whole blood was drawn from 115 healthy donors (73 males, 42 females) aged 21 - 62 years (mean 36, SD 10). The PRP was separated by the blood bank (BB) using the discontinuous cell separation method or at the 'point-of-care' by the so-called 'buffy coat' method (analogous to the Curasan PRP Kit). Growth factor content differed significantly for TGF-beta1 (BB 268.65+/-70.77 ng/ml, Curasan 95.02+/-60.67 ng/ml (sign test P<0.001)) and PDGF-AB (BB 133.59+/-46.26 ng/ml, Curasan 233.70+/-111.86 ng/ml (P<0.001)), while the content of IGF-I (BB 85.37+/-25.58 ng/ml, Curasan 101.72+/-47.7 ng/ml (P<0.160)) showed no significant difference. The higher thrombocyte count in the BB PRP (BB 1434300+/-351960/ microl, Curasan 908.500+/-492.30/microl) seems to result in higher TGF-beta1 levels, while the higher leukocyte count in the Curasan PRP (BB 160+/-320/ microl, Curasan 30130+/-12500/microl) seems to result in higher PDGF-AB levels. The similar IGF-I levels in the two preparations might merely reflect similar amounts of plasma in the PRP produced by each approach.

Adult↗

PubMed2002

Quantification of thrombocyte growth factors in platelet concentrates produced by discontinuous cell separation.

Platelet concentrates (PC) are increasingly used to increase bone regeneration in pre-prosthetic surgery. Although it is generally appreciated that certain growth factors (PDGF, TGF, EGF, and ECGF) are present in thrombocyte preparations, relatively little is known about these components in quantitative terms. The study reported here analysed the amounts of growth factors in PC produced under standard conditions from healthy volunteers. All the blood samples (237 in total) were analysed using Quantikine ELISA kits (R and D). The mean +/- SD platelet count in whole blood from these donors was 262,000+/-58,000/microl, while in PC produced by discontinuous cell separation it was 1.419,000+/-333,000/microl. The mean growth factor concentrations in PC preparations in ng/ml were as follows: PDGF-AB 125+/-55 ng/ml; TGF-beta1 221+/-92 ng/ml; IGF-I 85+/-25 ng/ml; PDGF-BB 14+/-9 ng/ml; TGF-beta2 0.4+/-0.3 ng/ml. These growth factor concentrations typically covered a 3-10 fold range: PDGF-AB 29-277ng/ml; PDGF-BB 2-33ng/ml; TGF-beta1 32-397ng/ml; TGF-beta2 0.1-1.2 ng/ml; IGF-I 40-138 ng/ml. Platelet counts in PC were slightly higher for women (Mann-Whitney Test all p < 0.001) than for men, while the concentrations of growth factors in PC exhibited no gender-related difference of any statistical significance.

Adult↗

PubMedDate not supplied

Primary stability of a conical implant and a hybrid, cylindric screw-type implant in vitro.

PURPOSE: The differences with respect to primary stability between 2 Camlog implants, a conical implant, and a hybrid cylindric screw-type implant, were investigated in vitro. The effect of underdimensioned implant bed preparation was also studied for both implant designs. MATERIALS AND METHODS: In an in vitro model the stability of different implants in fresh porcine iliac bone blocks was measured using torque moment values, the Periotest, resonance frequency analysis, and push-out testing. RESULTS: The conical implant showed significantly higher primary stability than the cylindric hybrid implant using the insertion torque, Periotest, and push-out tests. For both types of implants, the torque moment values following under-dimensioned preparation were significantly better than those obtained following the standard drilling protocol (Conical: 25.00 vs 11.00 Ncm; Cylindrical: 11.75 vs. 5.75 Ncm). For the cylindric implant, significantly better results following under-dimensioned implant bed preparation were observed only with the insertion torque and the pushout testing values. The mean ISQ values for all groups were between 55 and 57; no statistical differences with respect to ISQ could be found. CONCLUSION: In this in vitro model conical implants showed higher primary stability than cylindric implants. The procedure of under-dimensioned drilling seemed to increase primary stability for both types of implants; however, the effect was only observable using insertion torque. RFA and Periotest, the noninvasive, clinical methods tested, did not clearly demonstrate this difference.

Animals↗

PubMedDate not supplied

Insertion torque and resonance frequency analysis of dental implant systems in an animal model with loaded implants.

PURPOSE: The aim of this study was to compare insertion torque and resonance frequency analysis of different implant systems in an animal model with loaded implants. MATERIALS AND METHODS: Three types of Brånemark implants (machined MkIII, TiUnite MkIII, and MkIV) and 2 types of Straumann implants (sandblasted, large-grit, acid-etched [SLA] and titanium plasma-sprayed [TPS]) were studied. Thirty-two implants of each type (n = 160) were placed in 16 beagle dogs. Maximum insertion torque values were recorded. After a healing period of 8 weeks, the implants were loaded for 3 months; the animals were then sacrificed. At placement, after healing, and at the end of the loading phase, resonance frequency analysis was performed and implant stability quotients (ISQs) were recorded. RESULTS: Higher insertion torque values were seen for the conical MkIV than for the MkIII. No difference was seen between the Brånemark and Straumann implants on the basis of ISQ value at placement. ISQ and insertion torque values were lower for the cylindric Straumann implants than for the self-tapping implants. For all implant systems a significant decrease in median ISQ was observed, with a median decrease ranging from 3 to 6. ISQ values for self-tapping implants remained stable after loading, whereas the ISQ values for non-self-tapping cylinders decreased. The maximum insertion torque values for failed and successful implants were not significantly different. Significantly higher ISQ values at placement were seen for successful implants (P =.003). Based on this model for ISQ, a threshold of 65.5 was identified, with a sensitivity of 83% and specificity of 61% for prediction of implant loss. ISQ values at the start of loading were not predictive of implant loss in the loading period. CONCLUSION: Caution should be used when judging implant systems on the basis of resonance frequency analysis and torque measurement.

Animals↗

PubMedDate not supplied

Clinical report with up to 4 years of follow-up on a cervically modified stepped screw-type implant.

PURPOSE: In 1998, a modification of the macrostructure of the Frialit-2 implant in the cervical region was introduced to stabilize peri-implant bone. Limited data are available on the clinical effect of this modification. Therefore, the soft-tissue situation, marginal bone loss, and implant failure rate were analyzed after 4 years of clinical experience with the modified Frialit-2 Synchro implant. MATERIALS AND METHODS: From 1998 to 2001, 190 cervically modified implants were placed and documented prospectively in 58 patients. Of these implants, 147 were placed in original jaw bone, 22 in areas augmented with local osteoplasty, and 21 in iliac crest bone graft. The main indications for implantation were an atrophic edentulous alveolar crest (n = 99) and support for a partial denture (n = 39), followed by restoration of a shortened dental arch (n = 28) and single tooth replacement (n = 24). In a special clinical examination, 39 patients with 134 implants were investigated. RESULTS: The average in situ time of the 134 implants was 23.1 months. Failing osseointegration (n = 10), peri-implantitis (n = 1), and tumor resection (n = 3) in 8 patients resulted in the failure of 14 of 190 implants (7.4%). One patient with 4 implants died (2.1%). Currently, 3 patients with a total of 6 implants have been lost to follow-up (3.1%), and 166 implants remain in situ (87.4% of 190). DISCUSSION: Using different implant success criteria, success rates of 88.8% and 82.8% were calculated. CONCLUSION: Based on the results, the Frialit-2 Synchro implant appears to be a useful implant system for the indications analyzed.

Alveolar Bone Loss↗