Anton Dunsche

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.

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.

Reconstruction of the lower lip: rationale to preserve the aesthetic units of the face.

Background: The boundaries of the aesthetic units of the face are often crossed after lower lip cancer surgery. The aim of this study was to compare the aesthetic and functional outcome after use of different operative techniques based on the concept of the aesthetic units of the face. Materials: Sixty-three patients were evaluated after lower lip reconstruction. The aesthetic outcome was recorded by standard photography evaluating the disruption of the boundaries of the aesthetic units of the face, lip projection, and the resulting facial expression. The functional outcome consisted of the evaluation of mouth opening, pouting, and lips at rest for the evaluation of mouth continence. Three techniques were used: wedge excision, the Webster-Fries method, and the step technique. The step technique was combined with an Abbé or an Estlander flap in defects involving more than two-thirds of the lip. Results: In defects involving up to one-third of the lip, the aesthetic outcome was better for the step technique than for wedge excision (a statistical trend was observed, p = 0.088). In defects involving two-thirds of the lip, the aesthetic and functional outcome was better using the step technique than the Webster-Fries method (p = 0.002), because the boundaries of the aesthetic units are respected. In defects involving more than two-thirds of the lip, the result was better using the step technique combined with the Abbé flap. Conclusion: The authors have shown that the step technique alone or combined with a flap of the opposite lip is a rational approach for preserving the aesthetic units of the face and its function.

The current state of facial prosthetics – A multicenter analysis

Even though modern surgical techniques are dominating reconstructive facial procedures, the capability to use facial epitheses for reconstruction is still an important skill for the maxillofacial surgeon. We present an international multicenter analysis to clarify which techniques are used to fixate facial prostheses. We contacted all maxillofacial departments in Germany, Austria, Switzerland and Norway which were registered with the German society for oral and maxillofacial surgery (DGMKG). These centers were asked via electronical mail to provide information on the type of epithesis fixation systems currently in use. The return rate from 58 departments was 43.1% (n = 25). Overall, implant fixation was the preferred fixation system (92%). Plates were the second most common fixation technique (32%). No centers reported the standard use of non-invasive fixation techniques for permanent epithesis fixation. The main retention systems in use were magnets (24/25), other retention systems are used much less often. The current preferred fixation technique for facial epitheses consists of implant-based, magnet-fixated epitheses. For nasal prostheses, a plate-based, magnet-fixated system is often used.

Current concepts in cleft care: A multicenter analysis

The current surgical techniques used in cleft repair are well established, but different centers use different approaches. To determine the best treatment for patients, a multi-center comparative study is required. In this study, we surveyed all craniofacial departments registered with the German Society of Maxillofacial Surgery to determine which cleft repair techniques are currently in use. Our findings revealed much variation in cleft repair between different centers. Although most centers did use a two-stage approach, the operative techniques and timing of lip and palate closure were different in every center. This shows that a retrospective comparative analysis of patient outcome between the participating centers is not possible and illustrates the need for prospective comparative studies to establish the optimal technique for reconstructive cleft surgery.

Zerebriformer kongenitaler Nävuszellnävus am Kapillitium Entfernung nach Expanderimplantation

ZusammenfassungWir berichten über einen 26-jährigen Mann, bei dem seit Geburt ein umfangreicher, zerebriform gefalteter Nävuszellnävus am Kapillitium vorlag. Aufgrund der starken ästhetischen Beeinträchtigung, der Keimbesiedelung mit Geruchsentwicklung und der Entartungsgefahr wurde der Nävus nach vorheriger Gewebsexpanderimplantation vollständig exzidiert und der Defekt durch einen Rotationsverschiebelappen verschlossen.AbstractA 26 year old man presented with a giant cerebriform nevus on the occiput. Clinical appearance of the nevus, maceration within the folding and risk of malignancy prompted us to perform a complete excision. The scalp defect was closed with a rotation flap following an implantation of a tissue expander.