[Surgical extraction of wisdom teeth].
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Germany↗
Biomedical subjects
H Terheyden
Publications and source records attributed to H Terheyden.
Prefabrication of vascularized bone grafts using recombinant human osteogenic protein-1--part 3: dosage of rhOP-1, the use of external and internal scaffolds.
In a previous study vascularized bone grafts were prefabricated with recombinant human osteogenic protein-1 (rhOP-1) using blocks of xenogenic bone mineral (BioOss) as scaffolds. The present study addressed the dosage of rhOP-1 and the combination of an external (mould) and internal scaffold (granular BioOss). In five Göttingen minipigs six prefabrication sites in the latissimus dorsi muscles were randomly assigned to groups a-f. Moulds were prepared by shaping collagen/polylactide membranes in a cylindrical form which was filled with 1g BioOss granules and rhOP-1 (a: 0; b: 50; c, f, e: 250; d: 1000 microg of rhOP-1, a-e: cylinder open to muscle, e cylinder perforated, f: cylinder open to subcutaneous fat). After 6 weeks a dose dependency of bone density (a-d: 0%; 9.4%; 15.8%; 31.1%) and vessel density (a-d: 0.3; 2.4; 7.9; 25.4 counts/view) was observed histomorphometrically. Muscular surrounding was advantageous to subcutaneous tissue. Perforations of the membranes increased vessel density and did not impair bone formation. Bone density decreased in the proximity of the polylactide membranes. The membrane material was too soft and partly collapsed and therefore needs not to be reconsidered. The use of BioOss granules with 1000 microg rhOP-1 per gram proved to be a suitable concept for prefabrication of bone transplants.
Absorbable Implants↗
Follow-up of collagen crosslink excretion in patients with oral squamous cell carcinoma and analysis of tissue samples.
The presence of an oral squamous cell carcinoma (OSCC) may be associated with increased urinary excretion of the markers of collagen degradation, hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP). We investigated the possibility of these markers predicting the presence of active disease. Patients from a current study on HP and LP were included as follows: Group 1a (OSCC with confirmed mandibular bony infiltration, n=12), group 1b (group 1a patients >6 months after successful treatment), group 2a (OSCC without evidence of mandibular bone infiltration, n=8), group 2b (group 2a patients >6 months after successful treatment), group 3a (recurrent OSCC, n=8), group 3b (group 3a patients >6 weeks later, symptoms unchanged) and group 4 (control group, n=74). Tissue samples from tumour tissue and adjacent healthy mucosa were additionally investigated for HP and LP concentrations (n=8). The decrease in the urinary concentrations of HP and LP was statistically significant between groups 1a and 1b (P<0.001 for HP and LP), but not between groups 2a and 2b (P=0.07 for HP and LP), while values in groups 1b and 2b were within the normal range. When comparing groups 3a and 3b, a significant increase was observed for LP (P=0.050), but not HP (P=0.208). In conclusion, successful treatment of OSCC with bony involvement may be associated with a reduction of urinary HP and LP, whereas ongoing disease may result in an increase of LP. HP and LP may both be useful markers of tumour progression in patients with OSCC.
Adult↗
Collagen crosslink excretion and staging of oral cancer.
Lysylpyridinoline (LP) and hydroxylysylpyridinoline (HP) are collagen crosslink residues of which the urinary concentration reflects the level of connective-tissue turnover. HP is ubiquitous in tissue, whereas LP is specific for bone. The purpose of this investigation was to assess the sensitivity and specificity of an increased urinary concentration of both HP and LP in indicating infiltration of mandibular bone by an oral squamous cell carcinoma (OSCC) or recurrence of the disease after successful therapy. We investigated the history and urine levels in 116 adult patients, who were divided into the following groups. Group 1: patients with OSCC with bone infiltration (n=17); group 2: patients with confirmed OSCC (n=12) without evidence of bone infiltration; group 3: patients with recurrence of an OSCC (n=13); group 4: patients without clinical evidence of disease (n=74). The range and upper limit of normal values (HP(max) and LP(max)) were measured from the normal controls in group 4. Levels of LP and HP were measured by HPLC and fluorescence detection. There was a significant difference in the average urinary levels of LP and HP between groups 1-4 (P<0.001). The presence of mandibular bone infiltration could be detected with a sensitivity and specificity of 100% when comparing groups 1 and 2. Presence of tumour tissue could be detected with a sensitivity of 90%. In conclusion, a normal LP concentration in patients with an OSCC strongly suggests that bone invasion by the disease has not taken place. If both urinary HP and LP are elevated, disease recurrence is highly likely.
Adult↗
The sebaceous nevus as part of the Schimmelpenning-Feuerstein-Mims Syndrome--an obvious phacomatosis first documented in 1927.
The sebaceous nevus is a common nevus and can be easily diagnosed because of its typical rough fatty surface due to its amount of sebaceous glands. In some rare cases, the sebaceous nevus is part of a genetic disorder, the Schimmelpenning-Feuerstein-Mims (SFM) syndrome. If the SFM syndrome is suspected, further investigation is necessary, because multiple organ involvement is highly likely. We suggest that diagnosis of the SFM syndrome is simple, considering the special linear arrangement of sebaceous nevi in cases of SFM syndrome.
Child↗
Oral lichenoid reactions associated with amalgam: improvement after amalgam removal.
BACKGROUND: The pathogenetic relationship between oral lichenoid reactions (OLR) and dental amalgam fillings is still a matter of controversy. OBJECTIVES: To determine the diagnostic value of patch tests with amalgam and inorganic mercury (INM) and the effect of amalgam removal in OLR associated with amalgam fillings. METHODS: In 134 consecutive patients 467 OLR were classified according to clinical criteria. One hundred and fifty-nine biopsies from OLR lesions were histologically diagnosed according to the World Health Organization criteria for oral lichen planus (OLP) and compared with 47 OLP lesions from edentulous patients without amalgam exposure. One hundred and nineteen patients were patch tested with an amalgam series. In 105 patients (357 of 467 lesions) the amalgam fillings were removed regardless of the patch test results and OLR were re-examined within a follow-up period of about 3 years. Twenty-nine patients refused amalgam removal and were taken as a control group. RESULTS: Eleven patients with OLR (8.2%) had skin lesions of lichen planus (LP). Histologically, the lesions in the OLR group could not be distinguished from those seen in the OLP group. Thirty-three patients (27.7%) showed a positive patch test to INM or amalgam. Amalgam removal led to benefit in 102 of 105 patients (97.1%), of whom 31 (29.5%) were cured completely. Of 357 lesions, 213 (59.7%) cleared after removal of amalgam, whereas 65 (18.2%) did not improve. In the control group without amalgam removal (n = 29) only two patients (6.9%) showed an improvement (P < 0.05). Amalgam removal had the strongest impact on lesions of the tongue compared with lesions at other sites (P < 0.05), but had very little impact on intraoral lesions in patients with cutaneous LP compared with patients without cutaneous lesions (P < 0.05). Patients with a positive patch test reaction to amalgam showed complete healing more frequently than the amalgam-negative group (P < 0.05). After an initial cure following amalgam removal, 13 lesions (3.6%) in eight patients (7.6%) recurred after a mean of 14.6 months. CONCLUSIONS: Of all patients with OLR associated with dental amalgam fillings, 97.1% benefited from amalgam removal regardless of patch test results with amalgam or INM. We suggest that the removal of amalgam fillings can be recommended in all patients with symptomatic OLR associated with amalgam fillings if no cutaneous LP is present.
Adult↗
Acceleration of callus maturation using rhOP-1 in mandibular distraction osteogenesis in a rat model.
The aim of this study was to assess if the application of rhOP-1 induces accelerated consolidation of the callus in mandibular distraction osteogenesis. In seven adult Wistar rats a bilateral osteotomy of the horizontal ramus of the mandible was performed in the molar region and a custom designed distractor was mounted to the mandible. With a rate of 0.7 mm per day the device was activated bilaterally after the seventh postoperative day. After seven days of distraction two times 50 microg rhOP-1 were injected on two subsequent days directly into the callus. The contralateral side received an injection of placebo solution. The animals were killed four weeks after the end of distraction. A three-point bending test revealed a significantly higher strength of the distracted mandible in the rhOP-1 side (66.3 N vs. 30.4 N, P=0.034, paired t-test). Undecalcified histological sections were examined using microradiography and fluorescence microscopy after sequential intravital polychromic labelling. A continuous bony bridging was seen in all rhOP-1 sites and in none of the control sites. The data indicate that rhOP-1 may be an option to accelerate callus maturation in mandibular distraction osteogenesis.
Animals↗
[Development of speech and facial skull growth after primary velopharyngoplasty in lip-jaw-palate clefts].
BACKGROUND: A two-armed, prospective, randomized study was performed to evaluate the influence of primary velopharyngoplasty on speech and facial growth in patients with cleft lip and palate. PATIENTS AND METHODS: Forty-two patients born between 1978 and 1982 were included. All patients were treated with an intravelar veloplasty, and 21 patients simultaneously with a velopharyngoplasty according to Sanvenero-Rosselli. The patients were examined at the age of 5, 10, 15, and 18 years according to the recommendations of the research group of the German Association of Craniomaxillofacial Surgery for minimal documentation. RESULTS: Patients treated with primary velopharyngoplasty showed a higher deficit in transversal growth of the maxilla of 0.6 mm in the molar region in adolescence in comparison to the control group. The sagittal growth of the maxilla was reduced at 2.6 degrees in the SNA angle. A statistically significant decrease in growth of the maxilla caused by primary velopharyngoplasty was not detectable (p > 0.05). The incidence of rhinophonia and dyslalia did not differ significantly. Primary velopharyngoplasty did not lead to speech improvement either in childhood or in adolescence. CONCLUSION: With regard to a potential decrease in growth of the maxilla and the disadvantages of a hindered nasal respiration, a primary velopharyngoplasty therefore does not seem to be indicated.
Adolescent↗
[Comparison of secondary and tertiary cleft jaw osteoplasty. 20 year analysis].
BACKGROUND: The aim of secondary cleft osteoplasty is to provide alveolar bone for the complete eruption of the canine and sometimes of the lateral incisor to the occlusal plane and, thus, preservation of a continuous dental arch. This concept has not changed during the last 20 years in our clinic, providing an opportunity for an analysis of a homogeneous group of cleft patients. This group of patients was compared with a similar group of tertiary osteoplasties, performed during the same time span in our clinic. MATERIAL AND METHODS: From 1980 to 1999, 376 cleft osteoplasties were performed in 295 patients, 264 of whom (136 secondary and 128 tertiary osteoplasties) were available for continuous prospective follow-up. Special emphasis was put on preoperative orthodontic treatment with removal of crossbites, oral hygiene, and meticulous disinfection. Autogenous cancellous iliac bone was used exclusively. RESULTS: The postoperative height of the interalveolar septum (Abyholm classes) was I (1/1, 69.4%/45.8%), II (> 3/4, 28.2%/41.7%), III (< 3/4, 2.4%/10%), and IV (complete failure, 0%/2.5%) (secondary vs tertiary). Complications were infections (6.6% vs 14%), fistulae (0.7% vs 5.8%), and external root resorption (0% vs 7.4%). The lateral incisor was aligned into the arch in 55.5% vs 29.8% and the canine was in the correct position in 100% vs 83.6% (secondary vs tertiary). CONCLUSION: Secondary cleft osteoplasty was more advantageous than tertiary due to better preservation of the neighboring teeth.
Adolescent↗
[In vivo studies of screw-bone contact of drill-free screws and conventional self-tapping screws].
Screw-bone contact (SBC) and bone remodeling of titanium drill-free screws or self-tapping screws should be compared. Each 10 titanium self-tapping miniscrews or microscrews, and each 10 titanium drill-free miniscrews or microscrews were inserted into the anterior wall of the frontal sinus of 5 Göttingen minipigs. Intraperitoneal injections of fluochromes (Xylenol, Calcein, Alizarincomplexon and Tetrazyklin) were performed between the 2nd and 9th postoperative week. The pigs were sacrificed after 6 months, the screw-bone blocks were resected and microradiographic, histologic and fluorescence microscopic examinations were carried out. In drill-free screws mean SBC was 88.4 (miniscrews) or 93.8% (microscrews). In self-tapping miniscrews mean SBC was 54.9, in microscrews 81%; the differences were significant in statistical analysis (t-test: p < 0.05). In fluorescence microscopy the amount of bone remodeling (ratio of residual versus newly formed bone) was measured. Significantly more of the residual bone was found in the region of the screw threads of drill-free screws (miniscrews: mean 71.8, microscrews: mean 67.9%) than in the region of screw threads of self-tapping screws (miniscrews: mean 33.1, microscrews: mean 42.4%; t-test: p < 0.05). The superior SBC of drill free screws in comparison to SBC of self-tapping screws and the higher amount of original bone in the threads of drill free screws explain the sufficient holding strength of drill free screws in clinical tests. Both results are important for osteosynthesis in regions where thin cortical bone is present, as in the central midface.
Animals↗
Acne with chronic recurrent multifocal osteomyelitis involving the mandible as part of the SAPHO syndrome: case report.
For 12 years, a 26-year-old man had acne conglobata and a non-suppurative diffuse sclerosing osteomyelitis of the mandible as part of a chronic recurrent multifocal osteomyelitis of the sternum, the pelvic bones, and the femoral head, and aseptic arthritis of the knee, the fibulotalar, and the sternoclavicular joints. This fulfills the formal criteria of the SAPHO syndrome. Repeated surgical and antibiotic treatment combined with hyperbaric oxygen caused partial improvement. Complete relief and partial disappearance of the scintigraphic lesions was achieved with long-term corticosteroids, non-steroidal anti-inflammatory drugs, minocycline, and isotretinoin.
Acne Vulgaris↗
Mandibular reconstruction with prefabricated vascularized bone grafts using recombinant human osteogenic protein-1: an experimental study in miniature pigs. Part II: transplantation.
Osteogenic Protein-1 (rhOP-1), also called bone morphogenetic protein-7 (BMP-7), is osteoinductive. The aim of this study was to present a new surgical technique: the prefabrication of a vascularized bone graft using rhOP-1 and its microsurgical transplantation. During 6 weeks, osteomuscular grafts were prefabricated in the latissimus dorsi muscle of five adult minipigs. Six hundred micrograms rhOP-1 on a carrier of xenogenic bone mineral in block form were used. The grafts were transplanted into defects of the mandibular angles performing a microsurgical anastomosis and using miniplates for fixation. Identical defects of the contralateral side were treated by direct application of 600 microg rhOP-1 and xenogenic bone mineral. A polychrome sequential labelling was applied. After transplantation the bone stayed viable, demonstrated by continuous apposition of fluorochromes (non-decalcified histologic sections) and bone scintigraphy. The reconstructive result was significantly superior in the prefabrication technique, assessed by histology and computerized tomography (CT). In conclusion, the method has a potential to become a clinical alternative for conventional vascularized bone grafts.
Anastomosis, Surgical↗
Mandibular reconstruction with a prefabricated vascularized bone graft using recombinant human osteogenic protein-1: an experimental study in miniature pigs. Part I: Prefabrication.
Osteogenic protein-1 (rhOP-1), also called bone morphogenetic protein-7 (BMP-7), is osteoinductive. It may be possible to reconstruct a mandible by local application of rhOP-1. However, in tumour patients this can be impossible due to scars or preceding radiotherapy. Usually vascularized bone grafts are indicated. The aim of this study was to prefabricate a vascularized bone graft in the latissimus dorsi muscle for microsurgical transplantation. In nine minipigs 600 microgram rhOP-1 were used with 8 ml xenogenic bone mineral (BioOss, Geistlich, Waldenburg, Germany) as a carrier and inserted into a pouch prepared in the M. latissimus dorsi. After 6, 12, and 24 weeks the grafts were harvested. The results were evaluated using computed tomography, histology, macro- and microangiography. A high yield of newly formed bone was obtained on the osteoconductive scaffold of the xenogenic bone. It was possible to create a vascularized osseous graft in the given shape of the BioOss blocks. In cross-sections, 68% of the scaffold was coated with new bone. The amount of new bone did not differ between the prefabrication times. Bone overgrowth was 2.1% of the graft volume. In conclusion, this study has shown that it can be possible to prefabricate a neomandible within a muscle graft, which then could be transferred for microvascular reconstruction of the mandible. Further research is required before this technique can be refined for clinical use.
Animals↗
51st Annual Meeting of Arbeitsgemeinschaft für Kieferchirurgie in conjunction with Arbeitskreis Oralpathologie und Oralmedizin and with Arbeitskreis für Forensische Odonto-stomatologie all with the German Dental Association (Deutsche Gesellschaft für Zahn-, Mund- und Kieferheilkunde).
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Duty to Warn↗
[Sinus floor augmentation with simultaneous implant insertion using recombinant human osteogenic protein-1].
INTRODUCTION: The purpose of this study was to examine whether the combination of an osteoinductive protein (recombinant human osteogenic protein-(rhOP-1 = bone morphogenetic protein-7) with natural bovine bone mineral (BioOss) would improve ossification and the bone-implant contact (BIC) in a sinus floor augmentation with simultaneous placement of implants. MATERIAL AND METHODS: In this study, the maxillary sinus floors in five miniature pigs were augmented with 3 ml BioOss containing 420 micrograms rhOP-1 on the test side and 3 ml BioOss alone on the control side. At the time of augmentation a titanium implant (ITI) was inserted from a laterocaudal direction. RESULTS: After 6 months of healing the sites of augmentation were removed and examined in non-decalcified sections by microradiography, fluorescence microscopy of sequentially labelled specimens and by histometry. On both sides, significant amounts of newly formed bone were observed. However, on the test sites, the BIC in the augmented area was 80.0% versus 38.6% on control sites. It can be concluded that the application of bone morphogenetic proteins caused a more rapid and enhanced osseointegration of simultaneously placed implants when compared to the bone substitute alone. DISCUSSION: Therefore recombinant human osteogenic protein-1 delivered by natural bone mineral has the potential to become a clinical alternative for autogenous bone grafts in sinus floor augmentation.
Animals↗
Analysis of the osseous/metal interface of drill free screws and self-tapping screws.
AIM: A comparison of metal/osseous interface and bone remodelling after insertion of different types of titanium bone screws in vivo. MATERIAL: Samples of five of each of the following bone screw types were inserted into the anterior wall of the frontal sinus of five Göttingen minipigs: self-tapping micro- (1.5mm) and miniscrews (2.0 mm) or drill free micro- (1.5 mm) and miniscrews (2.0 mm) (Martin Medizintechnik, Tuttlingen, Germany). Screw length was 7mm. METHODS: Sequential intraperitoneal injections of fluorochromes were performed between the second and ninth postoperative week. After 6 months the pigs were sacrificed, the screw-bone-blocks resected, and microradiographic, histological and fluorescence microscopical examinations were carried out. RESULTS: Using drill free screws, mean screw/bone contact was 88.4% (miniscrews), or 93.8% (microscrews). With self-tapping miniscrews it was 54.9%, but in microscrews 81%; the differences were statistically significant (t-test: p<0.05). By fluorescence microscopy, the amount of bone remodelling (ratio of residual vs. newly formed bone) was measured. Significantly more of the residual bone was found in the region of the screw threads using drill free screws (miniscrews: mean 71.8%, microscrews: mean 67.9%) than in the region of screw threads with self-tapping screws (miniscrews: mean 33.1%, microscrews: mean 42.4%). CONCLUSION: The present data support the view that screw/bone contact with drill free screws was superior to that of self-tapping screws; the greater amount of original bone in the threads of drill free screws demonstrated that the insertion of drill free screws did not cause harm to the surrounding bone. Both results are important for osteosynthesis in regions where thin cortical bone is present, such as the central midface.
Animals↗
Three-dimensional cultivation of human osteoblast-like cells on highly porous natural bone mineral.
In this study, we investigated the growth and extracellular matrix synthesis of human osteoblast-like cells on highly porous natural bone mineral. Human bone cells were isolated from trabecular bone during routine iliac crest biopsies. Under conventional culture conditions, trabecular bone cells were able to assume the organization of a three-dimensional structure on a porous natural bone mineral (Bio-Oss(R) Block). Scanning electron microscopy examination after 6 weeks revealed multiple cell layers on the trabecular block. Transmission electron microscopy examination after 6 weeks revealed the accumulation of mature collagen fibrils in the intracellular and extracellular spaces, and showed multilayered, rough endoplasmic reticulum as well as mitochondria-rich cells surrounded by dense extracellular matrix. These morphological observations suggest that the cell layer may resemble the natural three-dimensional structure. Biochemical analysis revealed that the hydroxylysylpyridinoline, lysylpyridinoline, and hydroxyproline content of the cell layer increased in a time-dependent manner, whereas in monolayer culture without natural bone mineral, no measurable amounts of hydroxylysylpyridinoline or lysylpyridinoline, and a barely measurable amount of hydroxyproline, were noted. Mature collagen extracted by ethylenediaminetetraacetic acid-demineralization from the cell layer on natural bone mineral showed an identical electrophoretic pattern to that observed in human bone, as evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The present study demonstrated an excellent biocompatibility of the highly porous natural bone mineral in a three-dimensional bone cell culture system, and thus its potential for tissue-engineered growth of human bone.
Amino Acids↗
Sterilization of elastic ligatures for intraoperative mandibulomaxillary immobilization.
Sterilization can influence the mechanical properties of elastic ligatures used for mandibulomaxillary immobilization. The aim of this study was to compare different sterilization protocols (ethylene oxide, autoclave, irradiation, plasma sterilization, povidone-iodine for 24 hours and 70% isopropyl alcohol for 24 hours) of three elastomers (natural rubber, silicone rubber, and polyurethane). Three mechanical variables were assessed in a testing machine: breaking strength, tensile strength and tensile strength after a 24-hour load (material fatigue). Natural rubber was most susceptible to mechanical alteration by sterilization and lost 46% of its breaking strength and 43% of its tensile strength after autoclaving. Polyurethane was more resistant (multiple comparison, Tukey-Kramer), but polyurethane ligatures stuck together after autoclaving. The protocols for low-temperature sterilization, ethylene oxide, irradiation, and plasma were superior to autoclaving and the disinfecting solutions. These data suggest that polyurethane sterilized with ethylene oxide is the material of choice.
2-Propanol↗