Efficacy of tissue engineered bone grafts containing mesenchymal stromal cells for cleft alveolar osteoplasty in a rat model.

UNLABELLED: The development of sufficient tissue engineered bone grafts for alveolar cleft osteoplasty could reduce the necessity of autogenous bone grafts and its donor site morbidity. The aim of the study was to evaluate tissue engineered bone grafts in an artificially created bone defect. Bone grafts were created in vitro colonizing a synthetic hydroxyapatite-tricalciumphosphate scaffold (BONITmatrix(®)) with either undifferentiated mesenchymal stromal cells (group 1) or osteogenic differentiated mesenchymal stromal cells (group 2). Cells were multiplied from bone marrow of donor rats. Unmodified scaffolds (group 3) and the tissue engineered bone grafts were inserted into artificial maxillary defects of 54 Lewis rats. In 18 animals the defects remained unfilled (control). After one, three and six weeks the rats were sacrificed. The defect was evaluated radiologically and histologically with regard to the remaining defect volume and diameter. Statistical analysis followed. The bone grafts led to a specific bone formation at the defect margin. No complete reunion of any defect was observed within the healing time. After six weeks, the remaining defect volume was 6.86 ± 3.21 mm(3) (control), 4.08 ± 1.36 mm(3) (group 1), 5.00 ± 0.84 mm(3) (group 2) 5.50 ± 1.05 mm(3) (group 3). The remaining defect diameter measured 2.63 ± 0.52 mm (control), 2.39 ± 0.23 mm (group 1), 2.53 ± 0.22 mm (group 2) and 2.70 ± 0.66 mm (group 3). In all experimental groups the defect volume and diameter decreased over time, which was significant for group 1 (p = 0.014), group 2 (p = 0.025) and group 3 (p = 0.048). The defect volume and width was significantly reduced for bone grafts containing undifferentiated cells compared to control (p = 0.035) or scaffolds only (p = 0.05). CONCLUSION: Tissue engineered bone grafts induce a pronounced bone formation in artificial bone defects compared to unfilled controls or scaffolds only.

Beyond yield: plant disease in the context of ecosystem services.

The ecosystem services concept provides a means to define successful disease management more broadly, beyond short-term crop yield evaluations. Plant disease can affect ecosystem services directly, such as through removal of plants providing services, or indirectly through the effects of disease management activities, including pesticide applications, tillage, and other methods of plant removal. Increased plant biodiversity may reduce disease risk if susceptible host tissue becomes less common, or may increase risk if additional plant species are important in completing pathogen life cycles. Arthropod and microbial biodiversity may play similar roles. Distant ecosystems may provide a disservice as the setting for the evolution of pathogens that later invade a focal ecosystem, where plants have not evolved defenses. Conversely, distant ecosystems may provide a service as sources of genetic resources of great value to agriculture, including disease resistance genes. Good policies are needed to support conservation and optimal use of genetic resources, protect ecosystems from exotic pathogens, and limit the homogeneity of agricultural systems. Research is needed to provide policy makers, farmers, and consumers with the information required for evaluating trade-offs in the pursuit of the full range of ecosystem services desired from managed and native ecosystems.

One-stage palate repair improves speech outcome and early maxillary growth in patients with cleft lip and palate.

There are several types of palatal surgery; each cleft centre chooses its own technique based on experience and treatment philosophy. The aim of this study was to compare speech outcome and maxillary growth in children with cleft lip and palate deformity after palate repair with either a one-stage or a two- stage procedure and to identify the better treatment protocol. In 24 children, speech outcome was assessed regarding resonance, nasal escape, compensatory articulations, facial grimace, and spontaneous speech. In addition, plaster models of 15 children were compared. In 12 children, a two-stage procedure was performed (group A): at the age of 9-12 months, an intravelar veloplasty for repair of the soft palate, and at the age of 24-36 months a bipedicled flap closure of the hard palate. In 12 children, the same techniques were used in a one-stage procedure, at the age of 9-12 months (group B). The children of group B showed less altered resonance and less nasal emission at 4 years of age compared to the children of group A. At 6 years, the children of group A had improved their speech skills, but they did not equal the results of group B. In the study models of group A at age 6 years, the transverse dimension (anterior and posterior width of the dental arch) was smaller than in the models of group B. The one-stage repair of cleft palate at the age of 9-12 months seems to have a more positive influence on speech development and early maxillary growth than the two-stage procedure.

Cell passage and composition of culture medium effects proliferation and differentiation of human osteoblast-like cells from facial bone.

Cells loose their capability to multiply and to differentiate when they are serial subcultivated. However, both, multiplication and differentiation are of utmost importance to obtain sufficient amounts of cells for the translation of tissue regeneration into cell based therapeutic approaches. Thus, for the clinical application more information about ideal culture conditions are necessary. Therefore, aim of this study was to assess culture conditions of human osteoblast-like cells during long-term culture focusing on effects of different culture media and ascorbic acid. Biopsies of maxilla and mandible were obtained from 17 patients to test different cell culture media and from 10 patients to analyse differentiation and proliferation related to number of subcultures and ascorbic acid content. Histochemical and immunhistochemical tests (EZ4U assay, ALP histochemistry, type I collagen immunohistochemistry, osteocalcin Elisa) were performed to determine cell proliferation and differentiation. Opti-MEM with 10% FCS produced statistically significant the highest increase in cell counts. The highest proliferation rate in long-term cultivation was seen in the 4th cell passage. A reciprocal relationship between cell proliferation and differentiation over 5 passages with a turning point in the 4(th) passage was found. An ascorbic acid content of 50 microg/ml triggered an optimal increase in differentiation. For osteoblast-like cells, Opti-MEM with 10% FCS proved to be the best culture medium. After 3 passages there is the highest amount of cells with osteogenic differentiation which is enhanced by the addition of ascorbic acid. This approach is suitable for tissue engineering of bone grafts.

Free DIEP-flap reconstruction of tumour related defects in head and neck.

The free deep inferior epigastric perforator flap (DIEP) is a well-established therapy for plastic reconstruction of the breast or defects of the lower extremity without distinct donor site morbidity. Because of its particular qualities we started to apply the DIEP-flap also in reconstruction of defects in the cranio-maxillofacial area. A series of 10 consecutive patients, who received a DIEP-flap for reconstruction of large soft tissue defects after ablative tumour surgery, was reviewed. Nine of the 10 flaps survived and uneventfully healing was observed in 8 of the 10 flaps. Primary layered closure of the abdominal wall was achieved in all cases and no complications at the donor site were observed. In our experience the DIEP may serve as a well considerable alternative to the rectus abdominis flap and the latissimus dorsi flap for bridging extensive reconstructions in the cranio-maxillofacial region. It offers the possibility for flap elevation simultaneously to the surgical procedures in the head and neck area. A special advantage of the DIEP-flap is the very low donor site morbidity.

[Transoral osteosynthesis of condylar neck fractures using a three-dimensional plate]. / Transorale operative Therapie von Kiefergelenkfrakturen mit einer 3D-Platte.

AIM: The transoral approach minimizes the risk of damaging the facial nerve. However, stable osteosynthesis with two miniplates at the proximal fragment is often not possible. To achieve a stable fixation also of condylar neck fractures a new delta-shaped plate was developed, which meets the biomechanical demands of this region. This plate was tested in a clinical study. PATIENTS AND METHODS: In total 11 patients suffering from 13 condyle fractures (Spiessl I: n=2, Spiessl II: n=10, Spiessl III: n=1, 3 bilateral fractures) were treated via a transoral approach and assessed clinically as well as radiologically in the follow-up period. Functional parameters and fracture alignment were assessed. RESULTS: After 6 months postoperative function had returned to normal with a mouth opening of 42 mm and pro- and laterotrusion of more than 5 mm. Postoperative radiographic controls showed a good fracture alignment in 7 of 8 patients respectively in 6 of 8 cases after 6 months. In 12 of 13 fractures directly postoperative and in 10 of 13 fractures 6 months postoperative, respectively, Towne's view radiographs showed an anatomical correct position. No plate fracture and no bending of plates were observed. Loosening of screws was found in 2 patients during plate removal. CONCLUSION: The newly developed three-dimensional plate was easy to handle, and a sufficiently stable osteosynthesis of condyle fractures was possible. This plate can be recommended for surgical fracture treatment via a transoral approach omitting extraoral scars and damage to the facial nerve.

[DiGeorge syndrome/velcardiofacial syndrome: oral and maxillofacial surgery]. / Das DiGeorge-Syndrom/velokardiofaziale Syndrom in der Mund-, Kiefer- und Gesichtschirurgie.

The DiGeorge syndrome/velocardiofacial syndrome is the most frequent chromosomal microdeletion syndrome. Partial deletion of chromosome 22q11 may lead to symptoms including facial dysmorphy, hypoparathyroidism, thymic aplasia, congenital heart disease, developmental retardation, and disturbance of speech development. According to the literature, 9% of patients have cleft palate, an additional 5% have a submucosal cleft, and a total of 32% show velopharyngeal insufficiency. We studied 64 children with a cleft, or with delayed speech development and a submucosal or occult cleft, for the presence of the 22q11deletion using fluorescent in situ hybridisation. Five patients had the 22q11 deletion. We conclude that patients presenting with nasal speech and additional anomalies should all be studied for the presence of submucosal or occult clefting and for the presence of the DiGeorge syndrome/velocardiofacial syndrome.

Cryosurgical treatment of genuine trigeminal neuralgia.

A newly developed cryoprobe for peripheral nerves allows surgeons to freeze branches of the trigeminal nerve at the infraorbital or the mandibular foramen without exposing the nerve or damaging the surrounding tissue. The probe has an outer diameter of 2.7mm, and a vacuum-insulated shaft to protect the adjacent tissue. It is designed to be inserted transmucosally. The cryoprobe was used in 19 patients to freeze the infraorbital nerve or the inferior alveolar nerve. At 4-8 months after cryotherapy sensation in the areas innervated by the treated nerve had returned, but pain was absent for at least 6 months. The pain recurred in 13 out of 19 patients within 6-12 months. However, it was possible to repeat the cryotherapy as the procedure was not stressful. Cryosurgery widens the range of methods available to treat trigeminal neuralgia.

Therapeutic effect of pyrophosphate analogues on cutaneous herpes simplex virus type 1 infection in guinea pigs.

We investigated the influence of disodium phosphonic formate (PFA-Na2) and trisodium thiophosphonic formate (TPFA-Na3), in comparison with acyclovir (Zovirax) and trisodium phosphonic formate (PFA-Na3) (Triapten) ointment, on the course of primary cutaneous herpes simplex virus infection in a guinea pig skin model. PFA-Na2 at 3.0%, TPFA-Na3 at 0.5% and PFA-Na3 at 0.5% as well as Triapten ointment (2.0% PFA-Na3) completely inhibited virus infection. Zovirax cream (5.0% acyclovir), applied five times (15 min., 4, 20, 24, and 28 h) after virus inoculation did not prevent virus infection. Similarly, application of Zovirax cream 5 times daily for 5 days did not prevent a vesicle formation following cutaneous herpes simplex virus infection of the guinea pig.