Ulrich Joos

Publications of Ulrich Joos

• The University Munster model surgery system for Orthognathic surgery. Part I - The idea behind.

  Authors: Ulrike Ehmer, Ulrich Joos, Stefanie Flieger, Dirk Wiechmann

  Head & face medicine. 05/2012; 8(1):14.

  ABSTRACT: BACKGROUND: We describe a procedure for diagnosis and planning for orthognatic surgery based on international standards. A special 2D planning based on lateral cephalograms (Axis OrbitalABSTRACT: BACKGROUND: We describe a procedure for diagnosis and planning for orthognatic surgery based on international standards. A special 2D planning based on lateral cephalograms (Axis Orbital Marker Lines System) realize a transmission to the SAM 2P articulator (3D) by means of the Axis Orbital Plane. METHODS: Former intraoperative measurement of the average height of the LeFort I osteotomy plane relative to the molar occlusal plane allow to construct a virtual osteotomy plane in the lateral cephalogram. This is the basis for the development of the Axis Orbital Marker Lines System (AO-MLS). RESULTS: The AO-MLS is presented graphically, and in detail, with construction guidelines. The system could be integrated into various lateral cephalometric analysis- and surgical prediction schemes. It forms the basis for a standardized transfer of the 2D planning to the 3D planning in the articulator, and vice versa. This procedure makes it possible to generate surgical planning protocols based on the model surgery, which represent the dislocations in the proximity of the real osteotomy planes. CONCLUSIONS: The Axis Orbital Marker Lines System (software component) in conjunction with the University Munster Model Surgery System (hardware system) increases the predictability of model operations in orthognathic surgery.

• Nasopharyngeal development in patients with cleft lip and palate: a retrospective case-control study.

  Authors: Kai Wermker, Susanne Jung, Ulrich Joos, Johannes Kleinheinz

  International journal of otolaryngology. 01/2012; 2012:458507.

  Introduction. The aim of this paper was to evaluate cephalometrically the nasopharyngeal development of patients with complete unilateral cleft lip and palate. Influencing factors were evaluated andIntroduction. The aim of this paper was to evaluate cephalometrically the nasopharyngeal development of patients with complete unilateral cleft lip and palate. Influencing factors were evaluated and cleft to noncleft subjects were compared to each other. Material and Methods. The lateral cephalograms of 66 patients with complete cleft lip and palate were measured and compared retrospectively to the cephalograms of 123 healthy probands. Measurements were derived from a standardized analysis of 56 landmarks. Results. We observed significant differences between cleft and control group: the cleft patients showed amaxillary retroposition and a reduced maxillary length; the inclination of the maxilla was significantly more posterior and cranial; the anterior nasopharyngeal height was reduced; the nasopharyngeal growth followed a vertical tendency with reduced sagittal dimensions concerning hard and soft tissue. The velum length was reduced. In the cleft group, an accumulation of mandibular retrognathia and an anterior position of the hyoid were observed. Skeletal configuration and type of growth were predominantly vertical. Conclusions. Our data provides a fundamental radiological analysis of the nasopharyngeal development in cleft patients. It confirms the lateral cephalogram as a basic diagnostic device in the analysis of nasopharyngeal and skeletal growth in cleft patients.

• Objective Assessment of Hypernasality in Patients with Cleft Lip and Palate with the NasalView System: A Clinical Validation Study.

  Authors: Kai Wermker, Susanne Jung, Ulrich Joos, Johannes Kleinheinz

  International journal of otolaryngology. 01/2012; 2012:321319.

  Introduction. The objective of this investigation was to evaluate the reliability and validity of the NasalView system as a screening tool for hypernasality within the scope of a routine diagnosticIntroduction. The objective of this investigation was to evaluate the reliability and validity of the NasalView system as a screening tool for hypernasality within the scope of a routine diagnostic procedure in cleft lip and palate patients. Material and Methods. In a collective of 95 patients with cleft and lip palate ranging from 4 to 25 years of age, hypernasality was exploited perceptually, patients were classified in four degrees, and nasalance was measured objectively with the NasalView system. Speech stimuli existed in one nasal and one nonnasal sentence; nasalance ratio and distance were calculated. Results. The test-retest error was within a range of 2%. Sensitivity ranged from 83.3% to 91.1% for the nonnasal sentence, from 70% to 78.4% for nasalance ratio and from 68.1% to 81.1% for nasalance distance. Specifity ranged from 87% to 93.1% for the nonnasal sentence, from 69.6% to 97.5% for nasalance ratio, and from 70.7% to 73.9% for nasalance distance. Conclusions. With a quick and gentle screening procedure, it is easily possible to identify hypernasal patients by an objective diagnostic tool of hypernasality, the NasalView system, with good reliability and validity.

• Release kinetics of VEGF165 from a collagen matrix and structural matrix changes in a circulation model.

  Authors: Johannes Kleinheinz, Susanne Jung, Kai Wermker, Carsten Fischer, Ulrich Joos

  Head & face medicine. 01/2010; 6:17.

  Current approaches in bone regeneration combine osteoconductive scaffolds with bioactive cytokines like BMP or VEGF. The idea of our in-vitro trial was to apply VEGF165 in gradient concentrations toCurrent approaches in bone regeneration combine osteoconductive scaffolds with bioactive cytokines like BMP or VEGF. The idea of our in-vitro trial was to apply VEGF165 in gradient concentrations to an equine collagen carrier and to study pharmacological and morphological characteristics of the complex in a circulation model. Release kinetics of VEGF165 complexed in different quantities in a collagen matrix were determined in a circulation model by quantifying protein concentration with ELISA over a period of 5 days. The structural changes of the collagen matrix were assessed with light microscopy, native scanning electron microscopy (SEM) as well as with immuno-gold-labelling technique in scanning and transmission electron microscopy (TEM). We established a biological half-life for VEGF165 of 90 minutes. In a half-logarithmic presentation the VEGF165 release showed a linear declining gradient; the release kinetics were not depending on VEGF165 concentrations. After 12 hours VEGF release reached a plateau, after 48 hours VEGF165 was no longer detectable in the complexes charged with lower doses, but still measurable in the 80 microg sample. At the beginning of the study a smear layer was visible on the surface of the complex. After the wash out of the protein in the first days the natural structure of the collagen appeared and did not change over the test period. By defining the pharmacological and morphological profile of a cytokine collagen complex in a circulation model our data paves the way for further in-vivo studies where additional biological side effects will have to be considered. VEGF165 linked to collagen fibrils shows its improved stability in direct electron microscopic imaging as well as in prolonged release from the matrix. Our in-vitro trial substantiates the position of cytokine collagen complexes as innovative and effective treatment tools in regenerative medicine and and may initiate further clinical research.

• Cytokeratin alteration in oral leukoplakia and oral squamous cell carcinoma.

  Authors: Thomas Fillies, Mirco Jogschies, Johannes Kleinheinz, Burkhard Brandt, Ulrich Joos, Horst Buerger

  Oncology reports. 09/2007; 18(3):639-43.

  Intermediate filaments are involved in cell migration and intracellular signal transduction pathways. In a variety of organs, the expression of distinct intermediary filaments are further associatedIntermediate filaments are involved in cell migration and intracellular signal transduction pathways. In a variety of organs, the expression of distinct intermediary filaments are further associated with distinct steps of malignant transformation. In this study, we seeked to define the cytokeratin (Ck) expression pattern in oral leukoplakia and oral squamous cell carcinoma (OSCC). One hundred and ninety-two patients with OSCC, 117 patients with oral leukoplakia without dysplasia (OL) and 23 with oral leukoplakia with dysplasia (squamous intraepithelial neoplasia) (OLD) of the oral cavity were investigated for the immunohistochemical expression of Ck 5-6, Ck 8/18, Ck 1 Ck 10, Ck 14, Ck 19 using the tissue microarray technique. Correlations between clinical features and the expression of cytokeratins were evaluated statistically by chi2 tests. The expression of Ck 8/18, Ck 19 and Ck 1 was seen in 3.1% (Ck 8/18), 12.5% (Ck 19), 75.4% (Ck 1) of all leukoplakias, 1.0% (Ck 8/18), 9.4% (Ck 19), 76.8% (Ck 1) in OL, 13.0% (Ck 8/18), 27.3% (Ck 19), 68.4% (Ck 1) in OLD and was significantly associated with the degree of dysplasia (Ck 8/18 p<0.01; Ck 19 p<0.01; Ck 1 p<0.01) and the acquisition of invasive growth properties. The highest frequencies were observed in invasive squamous cell carcinomas. The expression of Ck 8/18 and Ck 19 in transformed oral lesions can be regarded as an early feature in the pathogenesis of invasive OSCC. However, the aberrant expression of Ck 8/18 and Ck 19 in an even higher frequency in invasive carcinomas characterizes the expression of typical glandular cytokeratins as a general progression marker in squamous cell carcinomas. These results can be interpreted as first hints that oral leukoplakias with an expression of Ck 8/18 or 19 independent of dysplasia, should be resected totally since they might indicate an increased progression potential.

• Treatment of hemimandibular hyperplasia: the biological basis of condylectomy.

  Authors: Carsten Lippold, Birgit Kruse-Losler, Gholamreza Danesh, Ulrich Joos, Ulrich Meyer

  The British journal of oral & maxillofacial surgery. 08/2007; 45(5):353-60.

  Treatments to correct skeletal deformities in patients with hemimandibular hyperplasia differ, particularly about the age at which the operation is done and the operation itself. To some extent, theTreatments to correct skeletal deformities in patients with hemimandibular hyperplasia differ, particularly about the age at which the operation is done and the operation itself. To some extent, the differences can be attributed to the unknown biological basis of disease. The aim of the present study was to evaluate clinically the outcome of a rationale for the operation based on condylectomy on the affected side. Histological, radiological, and nuclear methods were used to get a more detailed insight into the reason for the operation. Six patients with hemimandibular hyperplasia were treated by a combined orthodontic-maxillofacial protocol. All patients had the affected joint removed. The histological morphology of each condylar specimen was compared with the bone scintigraphy to try and find a correlation between the methods. The clinical evaluation showed morphological and functional rehabilitation of all six patients. During the 2-year follow-up, all patients had stable symmetrical mandibles with no disturbance of temporomandibular function. Remodelling of the joint and the destruction of the cartilaginous layer was accompanied by much bone scintigraphic activity. We conclude that condylectomy can correct hemimandibular hyperplasia, even in patients with active condylar growth, by removing the underlying disease.

• Cell cycle regulating proteins p21 and p27 in prognosis of oral squamous cell carcinomas.

  Authors: Thomas Fillies, Mike Woltering, Burkhard Brandt, Jean-Paul Van Diest, Richard Werkmeister, Ulrich Joos, Horst Buerger

  Oncology reports. 03/2007; 17(2):355-9.

  Cyclin-dependent kinases (CDKs) and cyclin-dependent kinase inhibitors (CDKIs), such as p21 and p27, exert a direct control on the cell cycle. p21 and p27 are negative regulators of cyclin-dependentCyclin-dependent kinases (CDKs) and cyclin-dependent kinase inhibitors (CDKIs), such as p21 and p27, exert a direct control on the cell cycle. p21 and p27 are negative regulators of cyclin-dependent kinases and in this function they are negative check-point regulators of the cell cycle. We therefore aimed to evaluate p21 and p27 expression in oral squamous cell carcinomas (OSSC) to determine the value as a prognostic marker. One hundred and ninety-two patients with histologically proven, surgically treated squamous cell carcinoma of the oral cavity were eligible for the study and investigated for the expression of p21 and p27 by means of tissue microarrays (TMAs). Immunohistochemical screening under identical condition were carried out with antibodies against p21 and p27. Correlations between clinical features and the expression of the respective antibodies were evaluated statistically by Kaplan-Meier curves, log-rank and chi(2) tests. The expression of p21 correlated significantly with an increased prognosis in the log-rang test (p=0.01). No significant correlation was found between the expression of p27 and the overall survival rate. In multivariate Cox analysis, p27 was indicated as independent predictor of survival prognosis in the subgroup of nodal positive carcinomas, p27 positive tumours showed a significantly better survival prognosis (p=0.03). p21 and p27 in carcinoma of oral cavity seem to be predictive parameter in regulation and prognosis of squamous cell carcinomas. A p21 negative subgroup of OSCC may benefit from additional radio or radiochemotherapy.

• Perioperative complications in infant cleft repair.

  Authors: Thomas Fillies, Christoph Homann, Ulrich Meyer, Alexander Reich, Ulrich Joos, Richard Werkmeister

  Head & face medicine. 02/2007; 3:9.

  BACKGROUND: Cleft surgery in infants includes special risks due to the kind of the malformation. These risks can be attributed in part to the age and the weight of the patient. Whereas a lot ofBACKGROUND: Cleft surgery in infants includes special risks due to the kind of the malformation. These risks can be attributed in part to the age and the weight of the patient. Whereas a lot of studies investigated the long-term facial outcome of cleft surgery depending on the age at operation, less is known about the complications arising during a cleft surgery in early infancy. METHODS: We investigated the incidence and severity of perioperative complications in 174 infants undergoing primary cleft surgery. The severity and the complications were recorded during the intraoperative and the early postoperative period according to the classification by Cohen. RESULTS: Our study revealed that minor complications occurred in 50 patients. Severe complications were observed during 13 operations. There was no fatal complication in the perioperative period. The risk of complications was found to be directly correlated to the body weight at the time of the surgery. Most of the problems appeared intraoperatively, but they were also followed by complications immediately after the extubation. CONCLUSION: In conclusion, cleft surgery in infancy is accompanied by frequent and sometimes severe perioperative complications that may be attributed to this special surgical field.

• The spectrum of Apert syndrome: phenotype, particularities in orthodontic treatment, and characteristics of orthognathic surgery.

  Authors: Ariane Hohoff, Ulrich Joos, Ulrich Meyer, Ulrike Ehmer, Thomas Stamm

  Head & face medicine. 02/2007; 3:10.

  In the PubMed accessible literature, information on the characteristics of interdisciplinary orthodontic and surgical treatment of patients with Apert syndrome is rare. The aim of the present articleIn the PubMed accessible literature, information on the characteristics of interdisciplinary orthodontic and surgical treatment of patients with Apert syndrome is rare. The aim of the present article is threefold: (1) to show the spectrum of the phenotype, in order (2) to elucidate the scope of hindrances to orthodontic treatment, and (3) to demonstrate the problems of surgery and interdisciplinary approach.Children and adolescents who were born in 1985 or later, who were diagnosed with Apert syndrome, and who sought consultation or treatment at the Departments of Orthodontics or Craniomaxillofacial Surgery at the Dental School of the University Hospital of Münster (n = 22; 9 male, 13 female) were screened. Exemplarily, three of these patients (2 male, 1 female), seeking interdisciplinary (both orthodontic and surgical treatment) are presented. Orthodontic treatment before surgery was performed by one experienced orthodontist (AH), and orthognathic surgery was performed by one experienced surgeon (UJ), who diagnosed the syndrome according to the criteria listed in OMIM. In the sagittal plane, the patients suffered from a mild to a very severe Angle Class III malocclusion, which was sometimes compensated by the inclination of the lower incisors; in the vertical dimension from an open bite; and transversally from a single tooth in crossbite to a circular crossbite. All patients showed dentitio tarda, some impaction, partial eruption, idopathic root resorption, transposition or other aberrations in the position of the tooth germs, and severe crowding, with sometimes parallel molar tooth buds in each quarter of the upper jaw.Because of the severity of malocclusion, orthodontic treatment needed to be performed with fixed appliances, and mainly with superelastic wires. The therapy was hampered with respect to positioning of bands and brackets because of incomplete tooth eruption, dense gingiva, and mucopolysaccharide ridges. Some teeth did not move, or moved insufficiently (especially with respect to rotations and torque) irrespective of surgical procedures or orthodontic mechanics and materials applied, and without prognostic factors indicating these problems. Establishing occlusal contact of all teeth was difficult. Tooth movement was generally retarded, increasing the duration of orthodontic treatment. Planning of extractions was different from that of patients without this syndrome.In one patient, the sole surgical procedure after orthodontic treatment with fixed appliances in the maxilla and mandible was a genioplasty. Most patients needed two- jaw surgery (bilateral sagittal split osteotomy [BSSO] with mandibular setback and distraction in the maxilla). During the period of distraction, the orthodontist guided the maxilla into final position by means of bite planes and intermaxillary elastics.To our knowledge, this is the first article in the PubMed accessible literature describing the problems with respect to interdisciplinary orthodontic and surgical procedures. Although the treatment results are not perfect, patients undergoing these procedures benefit esthetically to a high degree.Patients need to be informed with respect to the different kinds of extractions that need to be performed, the increased treatment time, and the results, which may be reached using realistic expectations.

• Malignant fibrous histiocytoma of the face: report of a case.

  Authors: László Seper, Richárd Schwab, Sirichai Kiattavorncharoen, Andre Büchter, Agnes Bánkfalvi, Ulrich Joos, József Piffkó, Birgit Kruse-Loesler

  Head & face medicine. 02/2007; 3:36.

  BACKGROUND: Soft tissue sarcomas in the head and neck region are rare and often present a difficult differential diagnosis. The aim of our presentation is to point out the complexity of theBACKGROUND: Soft tissue sarcomas in the head and neck region are rare and often present a difficult differential diagnosis. The aim of our presentation is to point out the complexity of the diagnosis, treatment and follow up. CASE PRESENTATION: An eighty-seven year old female patient was referred to our unit with a fast growing brownish lump on the face. Four months beforehand, a benign fibrous histiocytoma (BFH) had been removed from the same location by excision biopsy with wide tumour-free resection margins. Excision biopsy of the recurrent lesion revealed a malignant fibrous histiocytoma (MFH). Radical tumour resection was completed by extended parotidectomy and neck dissection; the skin defect was covered by a regional bi-lobed flap. No adjuvant radio- or chemotherapy was administered. Full functional and cosmetic recovery was achieved; follow-up has been uneventful more than two years postoperatively. DISCUSSION: Malignant transformation of BFH is extremely rare and if so, extended radical surgery may give a fair chance for a favourable outcome even in patients with advanced age.

• Influence of treatment concept, velopharyngoplasty, gender and age on hypernasality in patients with cleft lip, alveolus and palate.

  Authors: Ulrich Joos, Kai Wermker, Birgit Kruse-Löesler, Johannes Kleinheinz

  Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery. 01/2007; 34(8):472-7.

  OBJECTIVES: The aim of this study was to analyse cleft patients for hypernasality following velopharyngoplasty. PATIENTS AND METHODS: 95 subjects (43 females, 52 males) with cleft lip, alveolus andOBJECTIVES: The aim of this study was to analyse cleft patients for hypernasality following velopharyngoplasty. PATIENTS AND METHODS: 95 subjects (43 females, 52 males) with cleft lip, alveolus and palate (4 - 25 years old) were analysed. Forty-three patients were treated according to the current protocol of the Cleft Palate/Craniofacial Malformations Centre of the Department of Cranio-Maxillofacial Surgery in Muenster ('MS+' group) and 52 patients were treated elsewhere according to different protocols. In 19 of the 95 patients a velopharyngoplasty had been performed. Hypernasality was judged perceptually and nasalance data was measured objectively using the NasalView system. RESULTS: Patients of the 'MS+' group showed significantly better results concerning hypernasality and nasalance data. Assessment of hypernasality and nasalance measurement showed no significant differences between subjects following velopharyngoplasty and those who had not had this operation. Gender and age did not correlate with hypernasality either. CONCLUSION: A functionally orientated treatment with early closure of lip and palate ensures optimal velopharyngeal function, optimal oro-nasal balance of resonance, low hypernasality and excellent nasalance data.

• Melanotic neuroectodermal tumor of infancy: systematic review of the literature and presentation of a case.

  Authors: Birgit Kruse-Lösler, Christoph Gaertner, Horst Bürger, László Seper, Ulrich Joos, Johannes Kleinheinz

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 09/2006; 102(2):204-16.

  Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, distinctive neoplasm of early infancy with rapid expansile growth and a high rate of recurrences. Most commonly the lesion affects theMelanotic neuroectodermal tumor of infancy (MNTI) is a rare, distinctive neoplasm of early infancy with rapid expansile growth and a high rate of recurrences. Most commonly the lesion affects the maxilla of infants during the first year of life, but it may also occur in the mandible, skull, brain, epididymis, and other rare locations. The origin of the tumor is the neural crest. The expansive, destructive, and rapid growth of MNTI and its effects on the surrounding tissues are the most obvious clinical features. Microscopically, large polygonal epithelioid cells resembling melanocytes, with variable deposits of melanin, and smaller neuroblast-like round cells characterize MNTI. Malignant transformation may occur. Since the first description in 1918, only 215 cases were reported up to the last extensive review in 1992. The present review supplements another 140 published cases of MNTI up to 2004, including an original case report. Clinical features, treatment alternatives, and follow-up are discussed.

• Central giant cell granuloma of the jaws: a clinical, radiologic, and histopathologic study of 26 cases.

  Authors: Birgit Kruse-Lösler, Raihanatou Diallo, Christoph Gaertner, Karl-Ludwig Mischke, Ulrich Joos, Johannes Kleinheinz

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 04/2006; 101(3):346-54.

  The clinical behavior of central giant cell granuloma (CGCG) of the jaws is variable and difficult to predict. Clinical data and follow-up information of 26 patients with CGCG were analyzed.The clinical behavior of central giant cell granuloma (CGCG) of the jaws is variable and difficult to predict. Clinical data and follow-up information of 26 patients with CGCG were analyzed. Histologic features were correlated with the clinical course of the disease. In 16 patients the CGCGs were asymptomatic; 10 lesions presented with aggressive growth, pain, massive swelling, root resorption, cortical perforation, and/or recurrence. These patients were younger and the lesions were larger than in the nonaggressive group. The histomorphometric analysis proved a significant increase in large giant cells, fractional surface area, and mitotic activity in aggressive CGCG lesions. Immunohistologic investigation (Ki-67 and p53 stain) revealed no significant differences. After surgical treatment, 3 patients with aggressive lesions developed a recurrence. The data show that clinical and histomorphometric features may be reliable indicators for the differentiation between aggressive and nonaggressive CGCG. This should be accounted for to improve the individual planning of the treatment and follow-up.

• New paradigm in implant osseointegration.

  Authors: Ulrich Joos, Ulrich Meyer

  Head & face medicine. 02/2006; 2:19.

  During the last years, implant dentistry has seen an dramatic increase as a treatment option in oral rehabilitation. This is based to a large extent on scientific advances and clinical improvementsDuring the last years, implant dentistry has seen an dramatic increase as a treatment option in oral rehabilitation. This is based to a large extent on scientific advances and clinical improvements in implantology. The extension of indications has broadened the opportunities to rehabilitate patients that were formerly considered to possess restricted indications to place implants. Additionally, patient desires (high aesthetic demands, fast prosthetic rehabilitation) were placed more in focus, resulting in new approaches in implant dentistry. As a result, the scientific and clinical community has reached high standards and at the same time has founded the basis for new opportunities in implantology. The advances are mirrored by a high number of high quality scientific papers, published in conventional and open-access journals. A major shift has thereby been observed in the understanding of implant healing, leading the basis for new implant systems that allow fast rehabilitation protocols. The term osseointegration needs a new understanding since an immediate osseointegration state can be present under distinct conditions.

• Biological and biomechanical evaluation of interface reaction at conical screw-type implants.

  Authors: Andre Büchter, Ulrich Joos, Hans-Peter Wiesmann, László Seper, Ulrich Meyer

  Head & face medicine. 02/2006; 2(1):5.

  ABSTRACT : BACKGROUND : Initial stability of the implant is, in effect, one of the fundamental criteria for obtaining long-term osseointegration. Achieving implant stability depends on theABSTRACT : BACKGROUND : Initial stability of the implant is, in effect, one of the fundamental criteria for obtaining long-term osseointegration. Achieving implant stability depends on the implant-bone relation, the surgical technique and on the microscopic and macroscopic morphology of the implant used. A newly designed parabolic screw-type dental implant system was tested in vivo for early stages of interface reaction at the implant surface. METHODS : A total of 40 implants were placed into the cranial and caudal part of the tibia in eight male Göttinger minipigs. Resonance frequency measurements (RFM) were made on each implant at the time of fixture placement, 7 days and 28 days thereafter in all animals. Block biopsies were harvested 7 and 28 days (four animals each) following surgery. Biomechanical testing, removable torque tests (RTV), resonance frequency analysis; histological and histomorphometric analysis as well as ultrastructural investigations (scanning electron microscopy (SEM)) were performed. RESULTS : Implant stability in respect to the measured RTV and RFM-levels were found to be high after 7 days of implants osseointegration and remained at this level during the experimented course. Additionally, RFM level demonstrated no alteration towards baseline levels during the osseointegration. No significant increase or decrease in the mean RFM (6029 Hz; 6256 Hz and 5885 Hz after 0-, 7- and 28 days) were observed. The removal torque values show after 7 and 28 days no significant difference. SEM analysis demonstrated a direct bone to implant contact over the whole implant surface. The bone-to-implant contact ratio increased from 35.8 +/- 7.2% to 46.3 +/- 17.7% over time (p = 0,146). CONCLUSION : The results of this study indicate primary stability of implants which osseointegrated with an intimate bone contact over the whole length of the implant.

• Cytokeratin 8/18 expression indicates a poor prognosis in squamous cell carcinomas of the oral cavity.

  Authors: Thomas Fillies, Richard Werkmeister, Jens Packeisen, Burkhard Brandt, Philippe Morin, Dieter Weingart, Ulrich Joos, Horst Buerger

  BMC cancer. 02/2006; 6:10.

  BACKGROUND: Intermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patientBACKGROUND: Intermediary filaments are involved in cell motility and cancer progression. In a variety of organs, the expression of distinct intermediary filaments are associated with patient prognosis. In this study, we seeked to define the prognostic potential of cytokeratin and vimentin expression patterns in squamous cell carcinomas (SCC's) of the oral cavity. METHODS: 308 patients with histologically proven and surgically treated squamous cell carcinomas of the oral cavity were investigated for the immunohistochemical expression of a variety of intermediary filaments including high- and low-molecular weight cytokeratins (Ck's), such as Ck 5/6, Ck 8/18, Ck 1, CK 10, Ck 14, Ck 19 and vimentin, using the tissue microarray technique. Correlations between clinical features and the expression of Cytokeratins and vimentin were evaluated statistically by Kaplan-Meier curves and multivariate Cox regression analysis. RESULTS: The expression of Ck 8/18 and Ck 19 were overall significantly correlated with a poor clinical prognosis (Ck 8/18 p = 0.04; Ck19 p < 0.01). These findings could also be reproduced for Ck 8/18 in primary nodal-negative SCC's and held true in multivariate-analysis. No significant correlation with patient prognosis could be found for the expression of the other cytokeratins and for vimentin. CONCLUSION: The expression of Ck 8/18 in SCC's of the oral cavity is an independent prognostic marker and indicates a decreased overall and progression free survival. These results provide an extended knowledge about the role of intermediary filament expression patterns in SCC's.

• Interface reaction at dental implants inserted in condensed bone.

  Authors: André Büchter, Johannes Kleinheinz, Hans-Peter Wiesmann, Mythili Jayaranan, Ulrich Joos, Ulrich Meyer

  Clinical oral implants research. 11/2005; 16(5):509-17.

  PURPOSE: The influence of the osteotome technique on the interface reaction of cylinder implants (SLA, ITI) was compared with the interface reaction of conventional implant insertion in an animalPURPOSE: The influence of the osteotome technique on the interface reaction of cylinder implants (SLA, ITI) was compared with the interface reaction of conventional implant insertion in an animal model. MATERIAL AND METHODS: A total of 64 implants were placed in the cranial and caudal tibia of 8 Göttinger minipigs. The implant site was prepared either by a conventional technique with drills (control group A) or by the osteotome technique (experimental group B). Bone tissue responses were evaluated by histomorphometry, fluorescence microscopy and scanning electron microscopy after 7 and 28 days of osseointegration. RESULTS: The average initial (7 days) bone-to-implant contact ratio was not statistically significantly different for the osteotome technique (35.88+/-2.94%) than for the control group (43.78+/-3.39%, P<0.095). After 28 days, the bone-to-implant contact ratio became statistically significantly higher when implants were inserted by conventional preparation (44.81+/-3.07% (group B), 63.47+/-4.87% (group A), P=0.003). Whereas fluorescence and immunhistologic examination revealed new bone formation with osteocalcin deposition directly at the implant surface in both groups, the extent of direct bone/implant contact was enhanced in conventionally prepared implant sites. SEM analysis confirmed an intimate bone to implant bond without fibrous tissue formation in places of direct contact at an ultrastructured level. CONCLUSION: Implant placement in conventionally prepared implantation sites is accompanied by an improved interface formation at an early stage of implantation.

• Incision design in implant dentistry based on vascularization of the mucosa.

  Authors: Johannes Kleinheinz, André Büchter, Birgit Kruse-Lösler, Dieter Weingart, Ulrich Joos

  Clinical oral implants research. 11/2005; 16(5):518-23.

  OBJECTIVES: The delivery of an adequate amount of blood to the tissue capillaries for normal functioning of the organ is the primary purpose of the vascular system. Preserving the viability of theOBJECTIVES: The delivery of an adequate amount of blood to the tissue capillaries for normal functioning of the organ is the primary purpose of the vascular system. Preserving the viability of the soft tissue segment depends on the soft tissue incision being properly designed in order to prevent impairment of the circulation. A knowledge of the course of the vessels as well as of their supply area are crucial to the decision of the incision. The aim of this study was to visualize the course of the arteries using different techniques, to perform macroscopic- and microscopic analyses, and to develop recommendations for incisions in implant dentistry. MATERIAL AND METHODS: The vascular systems of seven edentulous human cadavers were flushed out and filled with either red-colored rubber bond or Indian ink and formalin mixture. After fixation a macroscopic preparation was performed to reveal the course, distribution and supply area of the major vessels. In the area of the edentulous alveolar ridge specimens of the mucosa were taken and analyzed microscopically. RESULTS: The analyses revealed the major features of mucosal vascularization. The main course of the supplying arteries is from posterior to anterior, main vessels run parallel to the alveolar ridge in the vestibulum and the crestal area of the edentulous alveolar ridge is covered by a avascular zone with no anastomoses crossing the alveolar ridge. CONCLUSION: The results suggest midline incisions on the alveolar ridge, marginal incisions in dentated areas, releasing incisions only at the anterior border of the entire incision line, and avoidance of incisions crossing the alveolar ridge.

• Strain driven fast osseointegration of implants.

  Authors: Ulrich Joos, Andre Büchter, Hans-Peter Wiesmann, Ulrich Meyer

  Head & face medicine. 10/2005; 1:6.

  BACKGROUND: Although the bone's capability of dental implant osseointegration has clinically been utilised as early as in the Gallo-Roman population, the specific mechanisms for the emergence andBACKGROUND: Although the bone's capability of dental implant osseointegration has clinically been utilised as early as in the Gallo-Roman population, the specific mechanisms for the emergence and maintenance of peri-implant bone under functional load have not been identified. Here we show that under immediate loading of specially designed dental implants with masticatory loads, osseointegration is rapidly achieved. METHODS: We examined the bone reaction around non- and immediately loaded dental implants inserted in the mandible of mature minipigs during the presently assumed time for osseointegration. We used threaded conical titanium implants containing a titanium2+ oxide surface, allowing direct bone contact after insertion. The external geometry was designed according to finite element analysis: the calculation showed that physiological amplitudes of strain (500-3,000 ustrain) generated through mastication were homogenously distributed in peri-implant bone. The strain-energy density (SED) rate under assessment of a 1 Hz loading cycle was 150 Jm-3 s-1, peak dislocations were lower then nm. RESULTS: Bone was in direct contact to the implant surface (bone/implant contact rate 90%) from day one of implant insertion, as quantified by undecalcified histological sections. This effect was substantiated by ultrastructural analysis of intimate osteoblast attachment and mature collagen mineralisation at the titanium surface. We detected no loss in the intimate bone/implant bond during the experimental period of either control or experimental animals, indicating that immediate load had no adverse effect on bone structure in peri-implant bone. CONCLUSION: In terms of clinical relevance, the load related bone reaction at the implant interface may in combination with substrate effects be responsible for an immediate osseointegration state.

• VEGF-activated angiogenesis during bone regeneration.

  Authors: Johannes Kleinheinz, Udo Stratmann, Ulrich Joos, Hans-Peter Wiesmann

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 10/2005; 63(9):1310-6.

  PURPOSE: The aim of this study was to investigate the influence of controlled release of recombinant human vascular endothelial growth factor (rhVEGF(165)) on angiogenesis and osteogenesis in aPURPOSE: The aim of this study was to investigate the influence of controlled release of recombinant human vascular endothelial growth factor (rhVEGF(165)) on angiogenesis and osteogenesis in a mandibular defect model. MATERIAL AND METHODS: A total of 56 rabbits were operated and bicortical holes were placed at the lower border of the mandible. The defects were filled with type-I collagen, with collagen complexed with 0.8 mug rhVEGF(165), or left without any filling. After 3, 7, 14, and 28 days, specimens were taken and histologic, histomorphometric, and immunohistologic analyses were carried out concerning number of vessels, cross-sectional area of vessels, and area and density of regenerated bone. RESULTS: Bone formation occurred in a typical centripetal direction and showed all stages of bone regeneration and maturation. New vessel formation took place in front of the osteogenic regeneration front. The number of vessels increased in all groups until day 14, followed by physiologic regression in the control groups as opposed to persisting high numbers in the study group. The area of newly formed bone showed no difference to the control group but the density of regenerated bone was significantly higher in the study group. CONCLUSION: Blood vessels are an important component of bone formation and maintenance and the bone tissue differentiation is related to the local presence of blood vessels. The activation of angiogenesis using rhVEGF(165) leads to more intensive angiogenesis and bone regeneration.