Marco Blessmann

Publications of Marco Blessmann

• Current trends and future perspectives of bone substitute materials - From space holders to innovative biomaterials.

  Authors: Andreas Kolk, Jörg Handschel, Wolf Drescher, Daniel Rothamel, Frank Kloss, Marco Blessmann, Max Heiland, Klaus-Dietrich Wolff, Ralf Smeets

  Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery. 01/2012;

  An autologous bone graft is still the ideal material for the repair of craniofacial defects, but its availability is limited and harvesting can be associated with complications. Bone replacementAn autologous bone graft is still the ideal material for the repair of craniofacial defects, but its availability is limited and harvesting can be associated with complications. Bone replacement materials as an alternative have a long history of success. With increasing technological advances the spectrum of grafting materials has broadened to allografts, xenografts, and synthetic materials, providing material specific advantages. A large number of bone-graft substitutes are available including allograft bone preparations such as demineralized bone matrix and calcium-based materials. More and more replacement materials consist of one or more components: an osteoconductive matrix, which supports the ingrowth of new bone; and osteoinductive proteins, which sustain mitogenesis of undifferentiated cells; and osteogenic cells (osteoblasts or osteoblast precursors), which are capable of forming bone in the proper environment. All substitutes can either replace autologous bone or expand an existing amount of autologous bone graft. Because an understanding of the properties of each material enables individual treatment concepts this review presents an overview of the principles of bone replacement, the types of graft materials available, and considers future perspectives. Bone substitutes are undergoing a change from a simple replacement material to an individually created composite biomaterial with osteoinductive properties to enable enhanced defect bridging.

• Bleeding incidence after oral surgery with continued oral anticoagulation.

  Authors: Wolfgang Eichhorn, Jens Burkert, Oliver Vorwig, Marco Blessmann, Georg Cachovan, Jürgen Zeuch, Marc Eichhorn, Max Heiland

  Clinical oral investigations. 12/2011;

  OBJECTIVES: The aim of this retrospective study was to assess the incidence of postoperative hemorrhage in patients treated with coumarins without interruption of the anticoagulant treatmentOBJECTIVES: The aim of this retrospective study was to assess the incidence of postoperative hemorrhage in patients treated with coumarins without interruption of the anticoagulant treatment undergoing oral surgical procedures, mostly osteotomies for tooth removal, when compared with patients who had never been anticoagulated. MATERIAL AND METHODS: Six hundred thirty-seven patients underwent 934 oral surgical procedures on an outpatient basis. The INR was measured preoperatively being 2.44 in the mean SD 0.61. Local hemostasis was carried out routinely (80%) with collagen fleece, local flap, and acrylic splint. RESULTS: Of these 637 patients, 47 presented with a postoperative hemorrhage (7.4%), 15 of these 47 cases had to be treated in hospital (2.4%). All patients showed up finally with a good wound healing, no administration of blood was necessary, and local measures revealed to be sufficient in all cases except for two patients, where the preoperative anticoagulant treatment had to be changed for 6 days. The bleeding incidence in 285 patients with comparable oral surgical procedures, who had never been anticoagulated, was 0.7%. CONCLUSIONS: The results suggest that oral surgical procedures can be performed safely without alteration of the oral anticoagulant treatment. CINICAL RELEVANCE: Local hemostasis with collagen fleece, local flap, and acrylic splint seems to be sufficient to prevent postoperative bleeding.

• Adhesion molecule L1 is down-regulated in malignant peripheral nerve sheath tumors versus benign neurofibromatosis type 1-associated tumors.

  Authors: Marco Blessmann, Alexander Gröbe, Alexander Quaas, Jussuf T Kaifi, Georgios Mistakidis, Christian Bernreuther, Guido Sauter, Stephanie Gros, Tamina Rawnaq, Reinhard Friedrich, Victor F Mautner, Ralf Smeets, Max Heiland, Melitta Schachner, Jakob R Izbicki

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 08/2011;

  Type 1 neurofibromatosis (NF-1), also known as von Recklinghausen disease, is caused by a disorder of a single gene on chromosome 17 that usually restrains cell division. A sequence that isType 1 neurofibromatosis (NF-1), also known as von Recklinghausen disease, is caused by a disorder of a single gene on chromosome 17 that usually restrains cell division. A sequence that is frequently associated with NF-1 is tumor progression from neurofibromas to malignant peripheral nerve sheath tumors (MPNSTs). The aim of this study was to determine the expression of the neural L1 cell adhesion molecule in dermal-diffuse neurofibromas, plexiform neurofibromas, and MPNSTs of NF-1. We retrospectively analyzed surgically resected primary tumors, including 20 dermal neurofibromas, 23 plexiform neurofibromas, and 17 MPNSTs, by immunohistochemistry in paraffin sections of NF-1 tumors with the use of the L1-specific monoclonal antibody UJ127, which does not cross-react with other members of the L1 family. Immunostainings for CD34 and S100 were included to distinguish and allocate L1-expressing Schwann cells and perineural (specialized) fibroblasts. Our data showed that L1 is highly expressed in all benign NF-1 tumors and in some but not all MPNSTs. Furthermore, we demonstrated a correlation between L1 expression and differentiation grade of MPNSTs. There was a significant trend toward lower or nondetectable expression in the poorly differentiated MPNSTs, in contrast to all other tumor entities so far investigated, in which L1 expression correlated positive with malignancy, except for juvenile but not adult-derived neuroblastomas. Future studies are warranted to elucidate the molecular basis of the varying effects of the degree of L1 expression, receptor, and signal transduction mechanisms in different tumors.

• A series of complications after third molar osteotomy in a pancytopenia patient and spontaneous healing after bone marrow transplantation.

  Authors: Jan C Klatt, Alexander Gröbe, Rainer Schmelzle, Artun Atac, Max Heiland, Marco Blessmann, Philipp Pohlenz

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 05/2011; 69(10):2508-12.

• Leech therapy in reconstructive maxillofacial surgery.

  Authors: Alexander Gröbe, Andreas Michalsen, Henning Hanken, Rainer Schmelzle, Max Heiland, Marco Blessmann

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 05/2011; 70(1):221-7.

  Corrective plastic surgery is indicated after accidents, burns, cancer surgery, or postoperative wound healing disorders with large tissue defects. The range of reconstructive techniques includesCorrective plastic surgery is indicated after accidents, burns, cancer surgery, or postoperative wound healing disorders with large tissue defects. The range of reconstructive techniques includes local skin flaps, pedicle grafts, and microvascular anastomosed flaps in the case of large defects. Main complications such as arterial and venous insufficiency caused by a vessel collapse or a vascular spasm are reported regularly in the area of anastomosed vessels and are the concern of any surgeon. Today, leeches are used if wound healing is at risk because of hemodynamic imbalance or a venous insufficiency. A retrospective evaluation of 148 patients who underwent medical leech therapy in the case of local or pedicaled flaps and some patients who had undergone reconstruction with microvascular flaps from 2005 and 2010 was conducted. Our sample had the typical symptoms of venous congestions of their flaps, despite suture removal, relief of pressure on the flap, and the elimination of a hematoma beyond the flap after surgery. Medical leech therapy was used in these cases. Our series has confirmed the excellent and predictable healing after medical leech therapy for local and microsurgical anastomosed flaps in the case of venous congestion. Leech therapy should be considered as a reliable additional procedure and an advantage in maxillofacial and plastic reconstructive surgery to remedy complications resulting from a hemodynamic imbalance or venous insufficiency in the immediate postoperative period.

• The influence of bisphosphonates on human osteoblast migration and integrin aVb3/tenascin C gene expression in vitro.

  Authors: Felix P Koch, Annette Wunsch, Christina Merkel, Thomas Ziebart, Andreas Pabst, Sareh Said Yekta, Marco Blessmann, Ralf Smeets

  Head & face medicine. 02/2011; 7(1):4.

  Bisphosphonates are therapeutics of bone diseases, such as Paget's disease, multiple myeloma or osteoclastic metastases. As a severe side effect the bisphosphonate induced osteonecrosis of the jawBisphosphonates are therapeutics of bone diseases, such as Paget's disease, multiple myeloma or osteoclastic metastases. As a severe side effect the bisphosphonate induced osteonecrosis of the jaw (BONJ) often requires surgical treatment and is accompanied with a disturbed wound healing.Therefore, the influence on adhesion and migration of human osteoblasts (hOB) after bisphosphonate therapy has been investigated by morphologic as well as gene expression methods. By a scratch wound experiment, which measures the reduction of defined cell layer gap, the morphology and migration ability of hOB was evaluated. A test group of hOB, which was stimulated by zoledronate 5 × 10(-5)M, and a control group of unstimulated hOB were applied. Furthermore the gene expression of integrin aVb3 and tenascin C was quantified by Real-Time rtPCR at 5 data points over an experimental period of 14 days. The bisphosphonates zoledronate, ibandronate and clodronate have been compared with an unstimulated hOB control. After initially identical migration and adhesion characteristics, zoledronate inhibited hOB migration after 50 h of stimulation. The integrinavb3 and tenascin C gene expression was effected by bisphosphonates in a cell line dependent manner with decreased, respectively inconsistent gene expression levels over time. The non-nitrogen containing bisphosphonates clodronate led to decreased gene expression levels. Bisphosphonates seem to inhibit hOB adhesion and migration. The integrin aVb3 and tenascin C gene expression seem to be dependent on the cell line. BONJ could be enhanced by an inhibition of osteoblast adhesion and migration. The gene expression results, however, suggest a cell line dependent effect of bisphosphonates, which could explain the interindividual differences of BONJ incidences.

• Influence of lip closure on alveolar cleft width in patients with cleft lip and palate.

  Authors: Wolfgang Eichhorn, Marco Blessmann, Oliver Vorwig, Gerd Gehrke, Rainer Schmelzle, Max Heiland

  Head & face medicine. 01/2011; 7:3.

  The influence of surgery on growth and stability after treatment in patients with cleft lip and palate are topics still under discussion. The aim of the present study was to investigate the influenceThe influence of surgery on growth and stability after treatment in patients with cleft lip and palate are topics still under discussion. The aim of the present study was to investigate the influence of early lip closure on the width of the alveolar cleft using dental casts. A total of 44 clefts were investigated using plaster casts, 30 unilateral and 7 bilateral clefts. All infants received a passive molding plate a few days after birth. The age at the time of closure of the lip was 2.1 month in average (range 1-6 months). Plaster casts were obtained at the following stages: shortly after birth, prior to lip closure, prior to soft palate closure. We determined the width of the alveolar cleft before lip closure and prior to soft palate closure measuring the alveolar cleft width from the most lateral point of the premaxilla/anterior segment to the most medial point of the smaller segment. After lip closure 15 clefts presented with a width of 0 mm, meaning that the mucosa of the segments was almost touching one another. 19 clefts showed a width of up to 2 mm and 10 clefts were still over 2 mm wide. This means a reduction of 0% in 5 clefts, of 1-50% in 6 clefts, of 51-99% in 19 clefts, and of 100% in 14 clefts. Early lip closure reduces alveolar cleft width. In most cases our aim of a remaining cleft width of 2 mm or less can be achieved. These are promising conditions for primary alveolar bone grafting to restore the dental bony arch.

• L1 is Highly Expressed in Tumors of the Nervous System: A Study of Over 8000 Human Tissues.

  Authors: Tamina Rawnaq, Alexander Quaas, Hilke Zander, Stephanie J Gros, Uta Reichelt, Marco Blessmann, Waldemar Wilzcak, Melitta Schachner, Guido Sauter, Jakob R Izbicki, Jussuf T Kaifi

  The Journal of surgical research. 11/2010;

  BACKGROUND: L1 cell adhesion molecule (CD171) has been detected in different malignant tumors and is associated with unfavorable outcome. It thus represents a target for tumor diagnosis and therapy.BACKGROUND: L1 cell adhesion molecule (CD171) has been detected in different malignant tumors and is associated with unfavorable outcome. It thus represents a target for tumor diagnosis and therapy. In this study, we assessed L1 expression in more than 8000 normal human tissues and different types of tumors, both malignant and non-malignant, and neural and non-neural. MATERIALS AND METHODS: Tissue micro-arrays, including a multi-tumor-array of 128 different tumor types, up to 50 samples of each type (approximately 5500 different samples), arrays with approximately 3000 different prostate and 600 mesenchymal tumor samples, and a normal human tissue-array were analyzed by immunohistochemistry with a monoclonal antibody using immunoperoxidase staining. RESULTS: L1 expression was detected in tumors of neural and neural crest origin and other types of non-neural tumors, but not in those of epithelial origin. In normal human tissues, L1 was detected in skin basal cells and small blood vessels, most notably in the mature placenta and peripheral nerves. CONCLUSION: This first comprehensive study of the importance of L1 expression in human demonstrates strong L1 overexpression in tumors of neuroectodermal and neural crest origin and an expression in only very few normal human tissues. L1 thus is a potentially important therapeutic target, particularly with respect to malignant melanoma, gastrointestinal stromal tumor, neuroblastoma, and certain subtypes of non-neural tumors.

• Metastases in odontogenic cysts: literature review and case presentation.

  Authors: Wolfgang Eichhorn, Manfred Wehrmann, Marco Blessmann, Philipp Pohlenz, Felix Blake, Rainer Schmelzle, Max Heiland

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 04/2010; 109(4):582-6.

  Malignant tumors in the oral cavity are relatively rare. About 5% of all malignant growths in the body are localized in the oral cavity. The vast majority of oral malignancies are primary tumors withMalignant tumors in the oral cavity are relatively rare. About 5% of all malignant growths in the body are localized in the oral cavity. The vast majority of oral malignancies are primary tumors with squamous cell carcinoma being the most frequent and sarcomas occurring very seldom. Secondary tumors caused by hematogenous spread arising from a tumor localized elsewhere in the body are extremely rare. About 1% of all oral cancers are metastases to the jawbones and the surrounding soft tissues. Metastases to the jaws are mainly caused by malignant tumors of the breast, lung, kidney, bone, and colon. They occur in the late state of the disease and are regularly detected by staging examinations including scintigraphy. Even more rare are metastases into odontogenic cysts. Odontogenic cysts include dentigerous cysts, periapical or radicular cysts, and the keratocysts-nowadays declared as keratocystic odontogenic tumor. The incidence of odontogenic cysts is about 10% to 15% of all oral biopsies and therefore general dentists are frequently faced with these types of lesions. The aim of this study was to review the literature regarding metastasis into odontogenic cysts and to further highlight this rare entity with the help of a clinical case.

• Clinical follow-up examination of surgically treated fractures of the condylar process using the transparotid approach.

  Authors: Jan Klatt, Philipp Pohlenz, Marco Blessmann, Felix Blake, Wolfgang Eichhorn, Rainer Schmelzle, Max Heiland

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 03/2010; 68(3):611-7.

  The surgical approaches for the open treatment of condylar process fractures have been controversial. In our study, we evaluated the morbidity of the transparotid approach during 2 years ofThe surgical approaches for the open treatment of condylar process fractures have been controversial. In our study, we evaluated the morbidity of the transparotid approach during 2 years of follow-up. A total of 48 patients with condylar process Class II and IV fractures according to classification of Spiessl and Schroll, were included in the present study. Of the 48 patients, 16 were female and 32 male. The patient age range was 16 to 79 years (average 36.52). All patients were treated using the transparotid approach, with rigid internal fixation using miniplates. Follow-up examinations were performed for a minimum of 6.5 months and a maximum of 25 months (average 12.16) after surgical treatment. At the follow-up examination, the patients completed the Mandibular Function Impairment Questionnaire, and the examiner completed the Helkimo index. X-rays taken before, directly after, and 6 months after surgery were compared. None of our patients had problems with wound healing; 2 patients developed a fistula of the parotid gland; and 4 patients developed palsy of the facial nerve that was completely reversible after 6 weeks. The results of the Mandibular Function Impairment Questionnaire and the Helkimo index revealed only a few subjective and objective problems after 6 months. The transparotid approach to condylar process fractures is most appropriate for strongly displaced Class II fractures. Especially for very old patients with dementia, for whom maxillomandibular fixation is contraindicated, this approach is very appropriate. Another benefit to this type of patient is the short operating time, with an average of 45 minutes.

• Primary osteoplasty using calvarian bone in patients with cleft lip, alveolus and palate.

  Authors: Wolfgang Eichhorn, Marco Blessmann, Philipp Pohlenz, Felix A S Blake, Gerd Gehrke, Rainer Schmelzle, Max Heiland

  Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery. 09/2009;

  PURPOSE: The results of primary bone grafting in terms of initial cleft width, existence or absence of a lateral incisor and scar formation in the donor area are compared. METHODS: After primaryPURPOSE: The results of primary bone grafting in terms of initial cleft width, existence or absence of a lateral incisor and scar formation in the donor area are compared. METHODS: After primary osteoplasty with calvarian bone at an average age of 24 months (4-56 months) radiographic assessment was carried out in 31 patients with 40 alveolar clefts. The bone formation in the grafted area was assessed using dental radiographs taken at 66 months on average (13-114 months) after primary bone grafting. According to the Abyholm classification patients were assigned to 4 groups (indices I-IV) with indices I and II being rated as a success. RESULTS: We observed success (indices I and II) in 76% and poor results (index IV) in 14%. The causes for the poor results were an alveolar cleft width of 11-12mm in three cases, an extraction of a decayed deciduous tooth 17 months after bone grafting in one case and a traumatic transplant loss in another case. The non-existence of a lateral incisor and a broad cleft are related to poor results. CONCLUSION: Based on the results presented, primary bone grafting using calvarial bone seems to be a promising alternative in bridging narrow alveolar defects. This method allows early intervention at an age in which children do not recognize themselves as cleft patients. The preservation of the deciduous teeth is equally important regarding their functional stimulus for bone development.

• Intraoperative cone-beam computed tomography in oral and maxillofacial surgery using a C-arm prototype: first clinical experiences after treatment of zygomaticomaxillary complex fractures.

  Authors: Philipp Pohlenz, Felix Blake, Marco Blessmann, Ralf Smeets, Christian Habermann, Philipp Begemann, Rainer Schmelzle, Max Heiland

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 04/2009; 67(3):515-21.

  PURPOSE: To describe the first clinical applications of intraoperative cone-beam computed tomography with an integrated flat-panel detector in oral and maxillofacial surgery after surgical treatmentPURPOSE: To describe the first clinical applications of intraoperative cone-beam computed tomography with an integrated flat-panel detector in oral and maxillofacial surgery after surgical treatment of zygomaticomaxillary complex fractures PATIENTS AND METHODS: Nine cone-beam computed tomography datasets of patients with zygomaticomaxillary complex fractures were intraoperatively acquired using a mobile isocentric C-arm (PowerMobil; Siemens Medical Solutions, Erlangen, Germany), including a flat-panel detector. Datasets based on 400, 200, and 100 fluoroscopic images were performed with different tube currents (4.6 mA, 3.3 mA, 2.3 mA, 1.2 mA, and 0.5 mA) and a current tube voltage of 100 kV. Postprocessing resulted in 15 different datasets available for comparison with corresponding preoperative computed tomography datasets. Four oral and maxillofacial surgeons and 2 experienced radiologists evaluated each dataset regarding noise, transition, and the delimitation of landmarks. RESULTS: All examinations were successfully performed. Reconstructed datasets showed high-resolution images of all midfacial osseous structures in near-computed tomography quality. Regarding high-contrast structures, detailed analyses of datasets acquired in this study suggest that the parameters 400 projections, 1.2 mA, and 100 kV are sufficient. In terms of soft-tissue visualization, a higher level of mA seems preferable. CONCLUSIONS: The tested prototype predicts a new era in cone-beam computed tomography imaging. The integration of a flat-panel detector will overcome the limitations of current available systems. The size of the field of view is increased allowing regularly the visualization of the whole facial skeleton. Particularly in cases of open reduction of unilateral fractures, the assessment of symmetry is of clinical value.

• 3D C-arm as an alternative modality to CT in postmortem imaging: technical feasibility.

  Authors: Philipp Pohlenz, Marco Blessmann, Lars Oesterhelweg, Christan R Habermann, Philipp G C Begemann, Christian Schmidgunst, Felix Blake, Dirk Schulze, Klaus Püschel, Rainer Schmelzle, Max Heiland

  Forensic science international. 04/2008; 175(2-3):134-9.

  OBJECT: The aim of our study was to demonstrate the image quality of the new device using human cadavers, extending the horizon of available imaging modalities in forensic medicine. MATERIALS ANDOBJECT: The aim of our study was to demonstrate the image quality of the new device using human cadavers, extending the horizon of available imaging modalities in forensic medicine. MATERIALS AND METHODS: Six human cadavers were examined, revealing C-arm data sets of the head, neck thorax, abdomen and pelvis. High-resolution mode was performed with 500 fluoroscopy shots during a 190 degrees orbital movement with a constant tube voltage of 100 kV and a current of 4.6 mA. Based on these data sets subsequent three-dimensional reconstructions were generated. RESULTS: Reconstructed data sets revealed high-resolution images of all skeletal structures in a near-CT quality. The same image quality was available in all reconstruction planes. Artefacts caused by restorative dental materials are less accentuated in CBCT data sets. The system configuration was not powerful enough to generate sufficient images of intracranial structures. CONCLUSION: After the here-demonstrated encouraging preliminary results, the forensic indications that would be suitable for imaging with a 3D C-arm have to be defined. Promising seems the visualization local limited region of interest as the cervical spine or the facial skeleton.

• Short tandem repeat polymorphism in exon 4 of esophageal cancer related gene 2 predicts relapse of oral squamous cell carcinoma.

  Authors: Marco Blessmann, Jussuf T Kaifi, Paulus G Schurr, Asli Cihan, Viacheslav Kalinin, Florian Trump, Artun Atac, Max Heiland, Philipp Pohlenz, Felix Blake, Rainer Schmelzle, Jakob R Izbicki

  Oral oncology. 03/2008; 44(2):143-7.

  Short tandem repeat (STR) polymorphisms in exon 4 of esophageal cancer related gene 2 (ECRG2) are a prognostic marker for squamous cell carcinoma (SCC) of the esophagus. The aim of the present studyShort tandem repeat (STR) polymorphisms in exon 4 of esophageal cancer related gene 2 (ECRG2) are a prognostic marker for squamous cell carcinoma (SCC) of the esophagus. The aim of the present study was to correlate these STRs with clinical outcome of the similar tumor type oral squamous cell carcinoma (OSCC). DNA of 81 patients that underwent complete surgical resection of OSCC was analyzed for STRs TCA3/TCA3, TCA3/TCA4 and TCA4/TCA4 in exon 4 of ECRG2 by PCR, capillary electrophoresis and DNA sequencing. ECRG2 STR TCA3/TCA3 were found in 45 (56%), TCA3/TCA4 in 33 (41%) and TCA4/TCA4 in 3 (3%) patients. TCA3/TCA3 was significantly associated with reduced relapse-free survival of OSCC, compared with TCA3/TCA4 and TCA4/TCA4 genotypes (P<0.05; log-rank test). TCA3/TCA3 STR was independent prognostic factor determined by multivariate Cox regression analysis (p<0.05). STR polymorphism TCA3/TCA3 in exon 4 of ECRG2 is associated with poor relapse-free survival in surgically completely resected OSCC patients and might be a potential prognostic marker.

• Major mandibular surgical procedures as an indication for intraoperative imaging.

  Authors: Philipp Pohlenz, Marco Blessmann, Felix Blake, Ali Gbara, Rainer Schmelzle, Max Heiland

  Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons. 03/2008; 66(2):324-9.

  PURPOSE: This study investigated 3-dimensional (3D) imaging with intraoperative cone beam computed tomography (CBCT) in major mandibular reconstruction procedures. PATIENTS AND METHODS: The studyPURPOSE: This study investigated 3-dimensional (3D) imaging with intraoperative cone beam computed tomography (CBCT) in major mandibular reconstruction procedures. PATIENTS AND METHODS: The study group was comprised of 125 patients (83 males, 42 females) admitted for surgical treatment of the mandible. The patients ranged in age from 3 months to 91 years (average age, 40.72 +/- 22.843 years). Surgical procedures of the mandible were subdivided into repair of body fractures (17 patients), angle fractures (21 patients), condylar fractures (14 patients), and multiple fractures (30 patient). In addition, the study group included 21 patients undergoing orthognatic surgery and 22 undergoing reconstructive surgery on the mandible. Intraoperatively, 3D images were generated with a mobile CBCT scanner (Arcadis Orbic 3D; Siemens Medical Solutions, Erlangen, Germany). RESULTS: During open reduction of mandibular fractures, not all fracture sites can be readily exposed for direct visual control. For example, the lingual cortical bone of the mandible is difficult to assess intraoperatively. This structure and others can be effectively visualized using the 3D mode of CBCT. Furthermore, screw placement can be evaluated, specifically in insertions near the alveolar nerve. The intraoperative acquisition of the data sets is uncomplicated, and the image quality is sufficient to allow evaluation of the postoperative result in all cases. CONCLUSION: Intraoperative CBCT has proven to be a reliable imaging technique for providing visual control during major mandibular procedures.

• Cervical soft tissue imaging using a mobile CBCT scanner with a flat panel detector in comparison with corresponding CT and MRI data sets.

  Authors: Max Heiland, Philipp Pohlenz, Marco Blessmann, Christian R Habermann, Lars Oesterhelweg, Philipp C Begemann, Christian Schmidgunst, Felix A S Blake, Klaus Püschel, Rainer Schmelzle, Dirk Schulze

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 01/2008; 104(6):814-20.

  OBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight freshOBJECTIVE: The aim of this study was to evaluate soft tissue image quality of a mobile cone-beam computed tomography (CBCT) scanner with an integrated flat-panel detector. STUDY DESIGN: Eight fresh human cadavers were used in this study. For evaluation of soft tissue visualization, CBCT data sets and corresponding computed tomography (CT) and magnetic resonance imaging (MRI) data sets were acquired. Evaluation was performed with the help of 10 defined cervical anatomical structures. RESULTS: The statistical analysis of the scoring results of 3 examiners revealed the CBCT images to be of inferior quality regarding the visualization of most of the predefined structures. Visualization without a significant difference was found regarding the demarcation of the vertebral bodies and the pyramidal cartilages, the arteriosclerosis of the carotids (compared with CT), and the laryngeal skeleton (compared with MRI). Regarding arteriosclerosis of the carotids compared with MRI, CBCT proved to be superior. CONCLUSIONS: The integration of a flat-panel detector improves soft tissue visualization using a mobile CBCT scanner.

• Intraoral osteotomies using piezosurgery for distraction in an infant with Pierre-Robin sequence.

  Authors: Max Heiland, Marco Blessmann, Philipp Pohlenz, Lei Li, Rainer Schmelzle, Felix Blake

  Clinical oral investigations. 10/2007; 11(3):303-6.

  Airway management in infants with Pierre Robin sequence (PRS) is often challenging. Advancement of the tongue base using mandibular distraction in neonates can avoid tracheotomy and is increasinglyAirway management in infants with Pierre Robin sequence (PRS) is often challenging. Advancement of the tongue base using mandibular distraction in neonates can avoid tracheotomy and is increasingly propagated. The osteotomies can be performed via intra- and extraoral approaches. Nowadays, for precise bone cutting, piezosurgical devices have been introduced in maxillofacial surgery, which we used for osteotomies via the intraoral approach in the 7-week-old patient presented in this study. Instead of a preoperative CT scan, a 3D data set was generated preoperatively in the operating theatre using a 3D C-arm system. After bilateral transcutaneous pin placement and osteotomies, a second 3D data set was acquired. Primary and secondary reconstructions clearly visualized the patient's bone despite the low level of ossification in newborns and the presence of a large amount of metal implants. In view of the low level of radiation exposure going along with the 3D C-arm imaging, a follow-up examination after removal of the distractors was performed. With this report of a 7-week-old female infant with the diagnosis of PRS, we want to extend the surgical and diagnostic armamentarium for the treatment of infants with PRS.

• Clinical indications and perspectives for intraoperative cone-beam computed tomography in oral and maxillofacial surgery.

  Authors: Philipp Pohlenz, Marco Blessmann, Felix Blake, Sven Heinrich, Rainer Schmelzle, Max Heiland

  Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics. 04/2007; 103(3):412-7.

  OBJECTIVES: Intraoperative cone-beam computerized tomography (CBCT) imaging has been introduced in oral and maxillofacial surgery. Using midfacial fractures as the pioneer model, this study describesOBJECTIVES: Intraoperative cone-beam computerized tomography (CBCT) imaging has been introduced in oral and maxillofacial surgery. Using midfacial fractures as the pioneer model, this study describes the spectrum of further promising clinical indications for intraoperative CBCT and a clinical combination with intraoperative navigation. STUDY DESIGN: One hundred seventy-nine patients admitted for surgical treatment of the facial skeleton were included in the study. Intraoperatively, 3-dimensional images were generated with the mobile CBCT scanner Arcadis Orbic 3D, obtained from Siemens Medical Solutions, in a variety of indications. RESULTS: The acquisition of the data sets was uncomplicated, and image quality was sufficient to assess the postoperative result in all cases. In the example of a facial gunshot injury, a navigation system for intraoperative localization of the metal foreign bodies was used.

• Outcome and complications of 540 microvascular free flaps: the Hamburg experience.

  Authors: Philipp Pohlenz, Marco Blessmann, Felix Blake, Lei Li, Rainer Schmelzle, Max Heiland

  Clinical oral investigations. 04/2007; 11(1):89-92.

  The aim of this study was to retrospectively analyze surgical outcome and complications of 540 free flap procedures performed at the Department of Oral and Maxillofacial Surgery of the UniversityThe aim of this study was to retrospectively analyze surgical outcome and complications of 540 free flap procedures performed at the Department of Oral and Maxillofacial Surgery of the University Medical Center Hamburg-Eppendorf during 1987-2005. A total of 532 patients were reconstructed with 540 flaps: 32% were latissimus dorsi flaps, 23% were radial forearm flaps, 21% were iliac crest flaps, 10% were fibula flaps, 6% were jejunal flaps, and 8% were other flaps. Thrombosis of one of the vessels and hematoma were the most frequent causes of failure in microvascular free tissue transfer. A total free flap failure occurred in 34 (6.2%) and a partial flap failure in 42 (7.7%) patients. The most reliable flap in regard to survival was the radial forearm flap. The present study confirms that free flaps are extremely reliable in achieving successful reconstruction of the head and neck.

• Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency with inadvertent caries in infants.

  Authors: Felix Blake, Marco Blessmann, Heiner Werle, Lei Li, Ali Gbara

  International journal of paediatric dentistry / the British Paedodontic Society [and] the International Association of Dentistry for Children. 02/2007; 17(1):72-4.

  BACKGROUND: Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare systemic disease that is associated with early tooth decay. CASE REPORT: This report describes the case of aBACKGROUND: Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare systemic disease that is associated with early tooth decay. CASE REPORT: This report describes the case of a 3-year-old boy suffering from LCHADD. At the time of referral, extensive carious lesions of the subject's maxillary dentition necessitated the surgical removal of eight teeth. Preventive treatment for LCHADD involves a regular oral intake of glucose that is vital for the survival of the affected individual. In young infants, the glucose solution needs to be administered as often as every 3 h in order to prevent hypoglycaemia, leading to a local environment similar to that experienced in nursing bottle syndrome. While nursing bottle syndrome can be resolved by eliminating the sugar substrate and curtailing the feeding sessions, these alternatives are not available in cases of LCHADD. CONCLUSION: This report highlights this rare disease and emphasizes its dire consequences for the dentition. Prophylactic recommendations for high-risk children are reviewed. Familiarity with LCHADD allows this high-risk group of patients to be identified, and thus, ensures diligent prophylactic action.