Biomedical subjects

Uwe Eckelt

Publications and source records attributed to Uwe Eckelt.

17 recordsLinked to original sources

PubMed2007

A comparison of MRI, radiographic and clinical findings of the position of the TMJ articular disc following open treatment of condylar neck fractures.

We examined the position and function of the articular disc after open treatment of condylar fractures by comparing magnetic resonance images (MRI) and radiographs with clinical data. MRI and radiographs were taken after treatment of 28 patients with 33 fractures of the mandibular condyles. In all cases, the disc was located in the fossa after open reduction and internal fixation (ORIF). The MRI, radiographic and clinical findings did not correlate, and damage to the temporomandibular joint (TMJ) could be seen more clearly on MRI than on clinical or radiographic examination. Damage to soft tissues seen on MRI after treatment was more pronounced in dislocated than in displaced fractures.

Adult↗

PubMed2007

Analysis of the base excision repair genes MTH1, OGG1 and MUTYH in patients with squamous oral carcinomas.

A number of environmental factors, such as tobacco and alcohol, have been implicated, through oxidative DNA damage, in the development of squamous cell carcinomas of the head and neck (SCCHN). Several pathways are involved in the repair of DNA lesions caused by oxidative stress, such as the base excision repair system (BER), which repairs mutation involving 8-oxoguanine and comprises the MUTYH, OGG1 and MTH1 genes. We analysed 29 patients, assessing germline polymorphisms or mutations in these genes by complete genomic sequencing of exons and adjacent intronic regions. Thirty healthy blood donors served as controls. No pathogenic germline mutations were identified. We found common and rare new variants in the coding and adjacent intronic regions. In summary, our data do not support a major role for MUTYH, OGG1 and MTH1 variants in the etiology of sporadic squamous oral/oropharyngeal carcinomas. This does not exclude the involvement of the three BER genes in the tumorigenesis of SCCHN through other mechanisms such as promotor hypermethylation, genomic rearrangements or mutations involving regulatory sequences.

Adult↗

PubMed2006

Commentary regarding the publication "Fractures of the mandibular condyle--a review of 466 cases. Literature review, reflections on treatment and proposals" by N. Zachariades et al.

The paper by Zachariades et al. presents a considerable contribution with regards to the epidemiology of condylar fractures. Hence, it is not possible to draw conclusions from this study with regards to the indication of open reduction or closed treatment. Only well-documented prospective and, if possible, randomized studies will be able to help us in the fracture. In the first prospective randomized study [Eckelt U, Schneider M, Erasmus F, Gerlach KL, Kuhlisch E, Loukota R, Rasse M, Schubert J, Terheyden H: Open versus closed treatment of fractures of the mandibular condylar process - a prospective randomized multi-centre study. J Cranio Maxillofac Surg 34: 306-314, 2006], advantages were observed for the open reduction and fixation of displaced fractures with stable osteosynthesis.

Fracture Fixation↗

PubMed2006

Open versus closed treatment of fractures of the mandibular condylar process-a prospective randomized multi-centre study.

AIM: The aim of this international prospective randomized multi-centre study was to compare operative and conservative treatment of displaced condylar fractures of the mandible. METHODS AND PATIENTS: Out of a total of 88 randomized patients from 7 centres, 66 patients with 79 fractures of the mandibular condylar process completed the study and were evaluated. All fractures were displaced, being either angulated between 10 degrees and 45 degrees or the ascending ramus was shortened by more than 2mm. The follow-up examinations 6 weeks and 6 months following treatment included evaluation of radiographic measurements, clinical, functional and subjective parameters including visual analogue scale for pain and the Mandibular Function Impairment Questionnaire index for dysfunction. RESULTS: Correct anatomical position of the fragments was achieved significantly more often in the operative group in contrast to the closed treatment group. Regarding mouth opening/lateral excursion/protrusion, significant (p=0.01) differences were observed between both groups (open 47/16/7mm versus closed 41/13/5mm). The visual analogue scoring revealed significant (p=0.03) differences with less pain in the operative treatment group (2.9 open versus 13.5 closed). The Mandibular Function Impairment Questionnaire index recorded a significant (p=0.001) difference with less pain and discomfort in the open treatment group (10.5 versus 2.4 points). CONCLUSION: Both treatment options for condylar fractures of the mandible yielded acceptable results. However, operative treatment, irrespective of the method of internal fixation used, was superior in all objective and subjective functional parameters.

Adult↗

PubMed2006

Resorbable poly(D,L)lactide plates and screws for osteosynthesis of condylar neck fractures in sheep.

We made osteotomies in the condylar neck in 12 adult sheep to simulate fractures, and joined the two ends with 2 poly(D,L)lactide (PDLLA) plates and 8 PDLLA screws 2mm in diameter. The animals were killed after 2, 6, and 12 months and bony healing was assessed macroscopically and histologically. The plates and screws remained intact and there was no displacement of the bony ends. The degrading plates, which were still visible in the specimens after 6 months, had been replaced by bone. At 12 months the PDLLA had been resorbed with no foreign body reaction and no resorption of underlying bone. The articular discs showed no signs of degeneration.

Absorbable Implants↗

PubMed2006

Bone regeneration after enucleation of mandibular cysts: comparing autogenous grafts from tissue-engineered bone and iliac bone.

OBJECTIVE: The aim of this study was to compare bone regeneration after grafting enucleated mandibular cyst cavities using either autogenous osteoblasts cultured on a biomaterial or autogenous spongiose iliac bone. STUDY DESIGN: Twenty patients with 22 mandibular cysts were assessed. Eleven cysts were filled in with tissue-engineered bone (autogenous osteblasts cultured on demineralized bone matrix Osteovit) and 11 with spongiose iliac bone as controls. Panoramic radiographs were taken preoperatively, immediately postoperatively, and 3, 6, and 12 months after surgery. Radiolucency was computer analyzed using gray-level histograms. RESULTS: In both groups bone regeneration took place in a similar fashion. After 3 and 6 months there were few differences in bone density between the groups. However, in radiographic controls after 12 months ossification was considerably stronger in cysts grafted with tissue-engineered bone. CONCLUSION: These results advocate for the clinical application of tissue-engineered bone as an alternative viable filling material for cysts.

Adolescent↗

PubMed2006

[Secondary midfacial reconstruction using different surgical techniques and computer assisted surgery].

AIM: Aim of this retrospective study was to assess the outcome after secondary midfacial reconstruction using different operation techniques and computer assisted surgery. Functional and aesthetic aspects as well as experiences are reported. PATIENTS AND METHODS: 18 patients were assessed for enophthalmos, diplopia, and aesthetics during a follow-up period of up to 2.5 years. RESULTS: In 40% of the patients several techniques for soft and hard tissue reconstruction were used. In 5 of the 9 patients diplopia was improved; in 4 patients there was no change. A significant enophthalmos was corrected in 8 out of 12 patients. After additional surgery 6 patients had a good aesthetic result, 7 a satisfactory and 5 a poor. CONCLUSION: For secondary midfacial reconstruction often a combination of different surgical techniques is necessary. Bony asymmetries and enophthalmos were successfully corrected, however, functional and aesthetic impairment due to bad soft tissue condition are difficult to correct. Computer assisted surgery is helpful for dissection within the orbit, for graft placement, and for positioning of osteotomized segments.

Adolescent↗

PubMed2006

Efficacy of computer-assited surgery in secondary orbital reconstruction.

PURPOSE: In this study the efficacy of computer-assisted surgery (CAS) used for secondary orbital reconstruction after midfacial fractures was evaluated, comparing the clinical outcome with that after conventional surgery (CS). Special consideration was given to whether CAS can reduce the number of secondary corrections. PATIENTS AND METHODS: Twenty consecutive patients (24 orbits; 12 in each group) were assessed for enophthalmos, diplopia, and aesthetics during a follow-up period of up to 3 years. RESULTS: After CAS, enophthalmos was fully corrected in 8 of 11 orbits but after CS in only 6 of 10 orbits. Improvement of diplopia was achieved in 1 of 7 (CAS) and in 3 of 4 (CS) patients. The aesthetic result after secondary reconstruction and additional surgery was better in the CAS group. Additional surgery to correct bony structures was only necessary in 3 patients of the CS group. Additional soft tissue surgery was necessary in both groups. CONCLUSION: CAS can improve the clinical outcome of reconstructive bone surgery reducing the amount of additional hard tissue procedures. It was helpful during dissection of the scarred orbital tissue and placement of a graft. However, it had no impact on soft tissue correction especially with respect to function.

Adolescent↗

PubMed2006

Minimally invasive fracture treatment with cannulated lag screws in intracapsular fractures of the condyle.

PURPOSE: We examined the use of cannulated lag screw osteosynthesis for the treatment of fractures of the mandibular condylar head in providing a high-quality durable fixation, while at the same time reducing the trauma necessary for an open approach to the fracture site. PATIENTS AND METHODS: A preauricular approach was used for exposure, reduction, and osteosynthesis in 5 cases of type B condylar fractures. A cannulated screw system was used that allowed optimum placement of the self-cutting cannulated lag screw following insertion of a guiding wire and using clinical control to ensure its correct position. The joints were submitted to functional exercises immediately following surgery and postoperative radiologic, axiographic, and clinical follow-ups were performed. RESULTS: Radiologic follow-up revealed correct reduction and fixation in all 5 cases. Axiographic and clinical follow-up showed an initial limitation, but normal mobility of the condyles was achieved within 3 months postoperatively, with a maximum mouth opening of 41.2 +/- 9.4 mm after 6 months. There were no occlusal disturbances, no trismus, no lateral deviations of the mandible, and no nerve lesions. Intraoperatively, the method applied shortened the time necessary for and simplified the procedure of reduction and osteosynthesis. CONCLUSION: By using a cannulated lag screw, it was shown that the major factor in the extent of the trauma relating to surgical access was the reduction of the fracture fragments. The method ensured stable fixation of the fracture with a minimum of osteosynthesis material, while reducing the operative time. In combination with intraoperative imaging techniques it can also successfully be applied to other fractures in maxillofacial surgery.

Biomechanical Phenomena↗

PubMed2005

Comparison of the predicted surgical results following virtual planning with those actually achieved following bimaxillary operation of dysgnathia.

AIM: To simulate the surgery of dysgnathia, several forms of computer software allowing two-dimensional 'virtual' planning are frequently used. However, in many cases it is not possible to transfer the virtual plan accurately to the surgical site. It is the purpose of this study to find the errors likely to occur when transferring the data. METHODS: In 22 bimaxillary osteotomies for dysgnathia, the results of preoperative planning were compared with the surgical outcomes. The programme WinCeph 4.19 (Compudent) was used for cephalometric analyses and simulation of the operations. RESULTS: Six major skeletal parameters were evaluated when comparing both the planned and the actual outcome, and the following results were recorded: Delta-SNA 1.53 degrees (+/-1.20), Delta-SNB 1.67 degrees (+/-1.29), Delta-ANB 1.62 degrees (+/-1.47), Delta-NL-NSL 3.9 degrees (+/-2.30), Delta-ML-NSL 3.6 degrees (+/-3.7) and Delta-ArGoMe 6.1 degrees (+/-4.6). CONCLUSION: It was anticipated that the most important differences between planned and surgical outcomes were found to be in the vertical changes. Planning and data transfer was comparatively accurate with regard to sagittal data. Apart from several mechanical methods for data transfer, systems using navigation are therefore being discussed and used increasingly. They ensure accurate data transfer to the surgical site.

Cephalometry↗

PubMed2005

Lag screw osteosynthesis of fractures of the mandibular condyle: potential benefit of preoperative planning using multiplanar CT reconstruction.

OBJECTIVE: The purpose of the study was to develop a method of multiplanar CT reconstruction in fractures of the mandibular condyle in order to evaluate the feasibility of lag screw osteosynthesis. STUDY DESIGN: Angulated axial and sagittal images of the mandibular ramus were calculated using collected CT data. In 183 mandibular rami the optimal position of the screw axis was determined retrospectively. The thickness of the covering bone as well as the degree of screw exposure were measured. RESULTS: Application of the method led to medial (28.4% of cases) or lateral (3.8% of cases) correction of the usual screw axis. In 1.6% of cases an extraosseous position of screws could not be avoided by this correction. CONCLUSIONS: Evaluation of the feasibility of lag screw osteosynthesis by this method is possible. Medial or lateral change of the axis ensures the optimal intraosseous screw position. Intraosseous screw placement is almost always possible.

Bone Screws↗

PubMed2005

Reduction of postoperative lymphedema after oral tumor surgery with sodium selenite.

The objective of this double-blind, randomized study was to establish whether sodium selenite administered orally or intravenously reduces postoperative lymphedema after oral tumor surgery and to study the effect of sodium selenite on glutathione peroxidase (GPX) activity and oxygen radical production. Twenty patients were enrolled in the study. Each of the participants received 1,000 microg sodium selenite intravenously or orally daily for 3 wk during the pre-, intra-, and postoperative period. The extent of lymphedema was measured for 2 wk and the plasma and whole-blood selenium concentration, GPX, reactive oxygen species (ROS), NO, and malonic dialdehyde were measured for 1 yr postoperatively. There was an inverse correlation between the severity of the lymphedema and the whole-blood/plasma selenium concentration and GPX activity. In addition, a positive correlation between the ROS concentration and the extent of lymphedema was observed. A significant reduction of lymphedema occurred in the sodium selenite-treated group. It is concluded that sodium selenite represents a suitable adjuvant treatment of secondary lymphedema in surgically treated patients with tumors in the oral and maxillofacial areas. Treatment with sodium selenite is especially advantageous as it can be instituted immediately after surgery prior to wound healing when manual lymphatic decongestion therapy cannot be applied.

Administration, Oral↗

PubMed2004

Loss of expression of ZAC/LOT1 in squamous cell carcinomas of head and neck.

BACKGROUND: ZAC/Lot1 is a previously identified candidate tumor suppressor gene. The gene maps to the human chromosome 6q24-q25, a region frequently deleted in squamous cell carcinomas of the head and neck and other solid tumors. METHODS: We have used a model of head and neck squamous cell carcinoma (HNSCC) and cell lines to analyze the role of the candidate tumor suppressor gene ZAC/Lot1 in oral carcinogenesis. We analyzed the expression in 11 cell lines, and we performed loss of heterozygosity (LOH)- and sequence analyses in 51 primary tumors. RESULTS: Three (27.3%) of 11 cell lines showed a distinctly reduced expression of ZAC/Lot1 compared with expression levels of the gene in the normal oral mucosa. In addition, we analyzed 51 primary squamous cell carcinomas of the head and neck for LOH with seven microsatellite markers flanking ZAC/Lot1. We detected an average LOH rate of 31.4% in the region of interest. Sequence analysis revealed no mutations for the ZAC/Lot1 coding exons, including the exon/intron boundaries. CONCLUSIONS: These data could suggest a minimal role for ZAC/Lot1 in a subgroup of HNSCC tumors.

Adult↗

PubMed2003

Analysis of complications in fractures of the mandibular angle--a study with finite element computation and evaluation of data of 277 patients.

AIM: The purpose of this study was to compute the load on different osteosynthesis plates in a simplified model using finite element analysis, and to find out whether miniplates were sufficiently stable for application at the mandibular angle. PATIENTS: Data from 277 patients with 293 fractures of the mandibular angle have been evaluated. METHODS: A computation model using finite elements was established in order to compute mechanical stress occurring in osteosynthesis plates used for fixation of fractures of the mandibular angle. In the second part of this study, the data from all in-patients treated for fracture of the mandibular angle were evaluated retrospectively. Age and sex of the patients, cause of fracture, state of dentition, type of therapy as well as complications were noted. RESULTS: In those tests, both the 1.0 mm miniplate and the 2.3 mm module plate were sufficiently stable. The rate of major complications (requiring revisional surgery with general anaesthesia) amounted to approximately 17% in comminuted fractures, or in non-compliant patients in which primary stability with a single miniplate did not appear sufficient, so that other osteosynthesis methods were used in addition. This rate was considerably higher than that in simple mandibular fractures. Simple fractures of the mandibular angle were just treated with one miniplate following Champy's guidelines strictly. In these fractures the rate of major complications was only 2.3%. CONCLUSION: In comminuted fractures and in non-compliant patients, the use of a stronger osteosynthesis material should be considered while in all other cases application of a single 1.0 mm miniplate was regarded as sufficient for fixation using open reduction.

Adolescent↗

PubMed2002

FDG-PET in the pretherapeutic evaluation of primary squamous cell carcinoma of the oral cavity and the involvement of cervical lymph nodes.

PURPOSE: The diagnostic role of positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) in squamous cell carcinoma of the oral cavity is evaluated. PROCEDURES: In 38 patients, the results of FDG-PET, magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound were compared. The standard uptake values (SUV) of FDG-PET were correlated to histopathological grading and DNA-image cytometry. RESULTS: In the case of lymph node metastases, the sensitivity of FDG-PET (93%) was higher than the sensitivity for the compared methods. The specificity was best for CT. SUVs of diploid tumor cell lines seemed to be lower than in non-diploid tumor cell lines. CONCLUSIONS: The high sensitivity and the high negative predictive value of PET may lead to more restrictive therapeutic regimens regarding lymph node metastases. Studies are necessary regarding possible relationships between glucose metabolism and tumor grading.

Journal Article↗

PubMed2002

Genetic polymorphisms of drug-metabolizing enzymes and susceptibility to oral cavity cancer.

We investigated the association of polymorphisms of drug-metabolizing enzymes and susceptibility to oral cavity cancer. Polymerase chain reaction (PCR)-based analyses were performed on genomic DNA of 94 Caucasian patients in Germany and 92 healthy German controls to determine genotypes of polymorphisms in CYP1A1, GSTM1 and NAT2. For CYP1A1, the homozygous mutant genotype Val/Val did not occur. The heterozygous genotype Ile/Val (6.5% cases versus 4.3% controls) and the homozygous wild-type Ile/Ile (95.7% cases versus 93.5% controls) showed no statistically significant differences between groups (X(2)=0.47; P=0.534, Fisher's exact test, two-sided). The GSTM1 homozygous null genotype occurred more frequently in cancer patients (59.6%) compared to controls (53.3%) but this difference remained insignificant in X(2)-analysis (X(2)=1.07; P=0.587). Almost identical genotype distributions between cases and controls were found for all three NAT2 acetylators. Hence, these three genetic polymorphisms are unlikely to be associated with oral cavity cancer in the population studied.

Adult↗

PubMed2002

Assessment of patients treated for intracapsular fractures of the mandibular condyle by closed techniques.

PURPOSE: The goals to study different lines of intracapsular fractures of the mandibular condyle and to evaluate their influence on the prognosis after closed treatment. PATIENTS AND METHODS: Clinical, radiologic, and axiographic follow-up of 40 patients with 50 intracapsular fractures of the mandibular condyle was carried out after closed treatment. The examinations were performed an average of 22 weeks after treatment. Three types of intracapsular fractures were distinguished: type A, or fractures through the medial condylar pole; type B, or fractures through the lateral condylar pole with loss of vertical height of mandibular ramus, and type M, multiple fragments, comminuted fractures. RESULTS: Moderate to serious dysfunction was observed in 33% of the cases. Radiologic examination of fracture types B and M revealed a reduction in the height of the mandibular ramus of up to 13% compared with the contralateral side. These 2 fracture types also resulted in the most prominent deformations of the condylar head. Axiography revealed irregular excursions and a limitation of condylar movement in comminuted fractures of up to 74% compared with the nonfractured side. CONCLUSION: Lesions to the osseodiscoligamentous complex of the temporomandibular joint caused by intracapsular fractures of the mandibular condyle can be severe. The poor functional and radiologic results encountered in the fracture types B and M showed the limitations of closed functional treatment.

Adolescent↗