Christoph Gaertner

Publications of Christoph Gaertner

• Load-related bone modelling at the interface of orthodontic micro-implants.

  Authors: André Büchter, Dirk Wiechmann, Christoph Gaertner, Marc Hendrik, Martin Vogeler, Hans-Peter Wiesmann, Josef Piffko, Ulrich Meyer

  Clinical oral implants research. 01/2007; 17(6):714-22.

  The purpose of this study was to determine the interface reaction of two different titanium micro-implant systems activated with different load regimens. A total of 200 micro-implants (100 AbsoThe purpose of this study was to determine the interface reaction of two different titanium micro-implant systems activated with different load regimens. A total of 200 micro-implants (100 Abso Anchor and 100 Dual Top) were placed in the mandible of eight Göttinger minipigs. Two implants each were immediately loaded in the opposite direction by various forces (100, 300 or 500 cN) through tension coils. Three different distances between the neck of the implant and the bone rim (1, 2, 3 mm) were used. The loads provided by superelastic tension coils (which are known to develop a virtually constant force) led to a range of tip moments 0-900 cN mm at the neck of implants. Non-loaded implants were used as a reference. Bone tissue responses were evaluated by histology, histomorphometry and scanning electron microscopy after 22 and 70 days of loading. Implant loosening was present in the groups where the load reached 900 cN mm. No movement of implants through the bone was found in the experimental groups, for any of the applied loads. A direct bone-to-implant contact to various extents was observed at differently loaded implants. Ultrastructural analysis confirmed the clinical and histological finding that implants (except when loaded at 900 cN mm) were well osseointegrated after 22 days. An increase in the bone-to-implant contact ratio was observed during the experimental period in the coronal part of the implants in most experimental groups. The difference reached a level of statistical significance at 500 cN mm (Abso Anchor) and 600 cN mm (Dual Top). We conclude that micro-implants can not only be loaded immediately without impairment of implant stability but many enhance bone formation at the interface when the load-related biomechanics do not exceed an upper limit of tip moment at the bone rim.

• 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.

• A clinical phase I/II trial of rhIL-4 applied topically in patients with oral squamous cell carcinomas to assess safety and therapeutic activity.

  Authors: Richard Werkmeister, Thomas Fillies, Christoph Gaertner, Ulrich Joos, Wolfgang E Berdel

  Oncology reports. 04/2005; 13(3):449-52.

  Besides its immunoregulatory effects, interleukin-4 (IL-4) has growth inhibitory activity on cells from human solid tumors, and IL-4 receptors are present on tumor cells including cells from head andBesides its immunoregulatory effects, interleukin-4 (IL-4) has growth inhibitory activity on cells from human solid tumors, and IL-4 receptors are present on tumor cells including cells from head and neck squamous cell carcinomas. We have conducted a phase I/II trial in patients with oral squamous cell carcinomas of T(4), N(+) (1 exception) stage to assess safety and therapeutic activity of recombinant human (rh) IL-4 applying the drug intratumorally 3 times a week with dose escalation for a duration of 4 weeks. A total of 7 patients entered the study using doses of 1, 3, and 5 microg/kg. There was no reduction of tumor size with 1 patient showing clear progression of the tumor after 4 weeks of treatment. This, and the observation of limiting toxicity occurring as local pain at the injection site, led to study termination. Therefore, rhIL-4 cannot be recommended as an antitumor drug in this disease using monotherapy with the schedules applied in this trial.