Publications by authors named "Philipp Jehn"

23 Publications

  • Page 1 of 1

Changes in Emergency Patient Presentation to a Maxillofacial Surgery Department During the COVID-19 Pandemic.

J Oral Maxillofac Surg 2021 May 25. Epub 2021 May 25.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Hannover, Germany.

Purpose: To examine possible changes in the emergency patient volume and reasons for presentation to an oral and maxillofacial surgery department during the coronavirus disease 2019 (COVID-19) pandemic and the resulting contact prohibitions. We hypothesized that the pandemic would lead to fewer patients presenting with emergent conditions.

Methods: A total of 939 patients, who presented to the Department for Oral and Maxillofacial Surgery of Hannover Medical School during the first 4 weeks of contact prohibitions in Germany, starting from March 23, 2020 until April 19, 2020, and in comparable periods were examined. The number of patients, reason for presentation, and required treatments were documented and compared to the years 2018 and 2019. Special attention was paid to the changes in trauma cases.

Results: We found that the number of patients in 2020 was significantly lower (P < .001, P < .01), but sex and age distributions were comparable to those in the previous years. Both the absolute and relative frequencies of dental diagnoses were significantly lower in 2020 (P < .001, P < .001), while the proportion of patients who presented with trauma was significantly higher (P < .001, P < .001). A significant decrease in patient number to the hospital, despite private practices being closed, was presumably due to patients' infection-related concerns. Trauma cases were more frequent in private settings, and traumatic events under the influence of alcohol were frequent. The circumstances and not the absolute number of trauma events had changed.

Conclusions: The results of this study suggest that the COVID-19 pandemic has important effects on the use of emergency services concerning oral and maxillofacial surgery in Germany.
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http://dx.doi.org/10.1016/j.joms.2021.05.026DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8146273PMC
May 2021

Comparison of original and universal screwdrivers: Damage to the surface of the socket within the screw head of the abutment screw

Swiss Dent J 2021 06;131(6):511-517

Medizinische Hochschule Hannover, Hannover, Deutschland.

The aim of the study was to investigate the potential damage the usage of universal screwdrivers could cause to the abutment screw. In this study the original versus the universal screwdriver have been compared. 26 original abutment screws, 13 from Straumann and 13 from BEGO, were screwed in with the original and the universal screwdriver. For optical evaluation, the potential damage to the screw head was documented in two different areas. For this purpose, photos were taken with a scanning electron microscope. At Straumann, surface damage was only seen in area 1 (top of the screw head) when using the universal screwdriver. BEGO showed surface damage in area 1 regardless of which screwdriver was used and in area 2 (bottom of the screw head) when using the universal screwdriver. It can be assumed that the use of the original screwdriver might cause little or no damage to the screw heads. In contrast, based on the SEM images, it can be assumed that the surface can be damaged when using the universal screwdriver.
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June 2021

Suitability of CD133 as a Marker for Cancer Stem Cells in Melanoma.

Asian Pac J Cancer Prev 2021 May 1;22(5):1591-1597. Epub 2021 May 1.

Department of Oral, Craniomaxillofacial and Facial Plastic Surgery, University Hospital of Leipzig, Germany.

Objectives: CD133 is considered a cancer stem cell (CSC) marker in various malignancies; however, its role as a biomarker of malignant melanoma remains controversial. The present study was conducted to evaluate the suitability of CD133 surface antigen as a CSC marker in melanoma.

Methods: Human melanoma cells were fractionally separated by magnetic cell separation depending on the CD133 phenotype and transplanted into immunodeficient mice to evaluate their tumorigenic capacity. Furthermore, the time until the development of a palpable tumor and the growth rate were measured, and the final tumor volume was assessed after 8 weeks. The immunohistochemical expression of CD133 in the induced neoplasia was then compared using histomorphometry.

Results: Notably, neoplasms were induced in all the groups (n = 48), including in the CD133-negative group. Tumors induced by unsorted cells had the largest volume (p = 0.014) but were detected significantly later in this group (p ≤ 0.001). Interestingly, all explanted tumors expressed CD133, with no significant differences among groups.

Conclusions: In contrast to the results obtained in prior studies, the suitability of CD133 as a CSC marker could not be demonstrated. The current encouraging progress in targeted therapy for malignant melanoma highlights the need to identify more effective targets.
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http://dx.doi.org/10.31557/APJCP.2021.22.5.1591DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8408398PMC
May 2021

Imaging, histopathological degree of degeneration and clinical findings - Do these correlate in patients with temporomandibular joint disorders.

J Stomatol Oral Maxillofac Surg 2021 May 12. Epub 2021 May 12.

Department of Oral and Maxillofacial Surgery, University Hospital Erlangen, Friedrich-Alexander-University Erlangen Nuremberg, Glückstraße 11, 91054 Erlangen, Germany; Section of Oral and Maxillofacial Surgery, Department of Otorhinolaryngology, University Hospital Augsburg, Stenglinstraße 2, 86156 Augsburg, Germany.

The gold standard for temporomandibular joint imaging is magnetic resonance imaging, although there are still pathological findings that cannot be seen in MRI but in surgery and the subsequent histological analysis only. The main goal of this investigation was to validate the MRI score used by histopathological findings as well as clinical findings. In this retrospective study 39 patients were included; 38 of which underwent unilateral and 1 underwent bilateral discectomy. MRI findings were graded according to the score by Wurm. Histopathological analysis was performed in hematoxylin-eosin staining and graded in accordance with the scores by Krenn and by Leonardi. For valuation of preoperative pain values of the temporomandibular joint operated on the numeric rating scale was utilized. Correlations were verified by Spearman-Rho. The MRI scores on average showed significantly lower scores for the discs of the operated temporomandibular joint than for the discs of the non-operated side(p<.01). No significant correlations between MRI findings, histopathological findings and pain intensities could be observed. Thus unsuspicious morphology of the TMJ and the articular disc in MRI is no guarantee for the absence of cartilage-degeneration. Further investigations utilizing T2 cartilage mapping could possibly show better correlations between the temporomandibular joint's degree of degeneration and imaging results.
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http://dx.doi.org/10.1016/j.jormas.2021.05.002DOI Listing
May 2021

Self-centering second-generation patient-specific functionalized implants for deep orbital reconstruction.

J Stomatol Oral Maxillofac Surg 2021 Sep 30;122(4):372-380. Epub 2020 Dec 30.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Hannover, Germany. Electronic address:

Deep and complete reconstruction of the orbital cavity has been shown to be essential for preventing enophthalmos and hypoglobus in patients with orbital defects or deformities. Additively manufactured patient-specific titanium implants provide unlimited options in design. However, implant malpositioning can still occur, even when intraoperative imaging and navigation are used. In this study, we investigated novel orbital implants containing features facilitating self-centering. Accuracy of implant placement and reconstruction of the orbital dimensions were compared retrospectively between self-centering second-generation patient-specific functionalized orbital implants (study group) and CAD-based individualized implants (control group). Design features of implants in the study group included functionalization with navigation tracks, a preventive design, and flanges - so called stabilizers - towards opposite orbital walls. Implant position was evaluated by fusion of preoperative virtual plans and the post-therapeutic imaging. Aberrances were quantified by 3D heatmap analysis. 31 patients were assigned to the study group and 50 to the control group, respectively. In the study group, most implants were designed with either one (n = 18, 58.06%) or two (n = 10, 32.26%) stabilizers. Twice (6.45%), one stabilizer had to be shortened intraoperatively. Implant fit analysis revealed a significantly more precise (p < 0.001) positioning in the study group (n = 22/31) than in the control group (n = 42/50). Self-centering second-generation patient-specific functionalized orbital implants showed significantly more accurate implant positioning, facilitating the transformation of virtual plans into patient's anatomy. The presented design provides an additional instrument for intraoperative quality control besides intraoperative imaging and navigation.
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http://dx.doi.org/10.1016/j.jormas.2020.12.007DOI Listing
September 2021

Accurate and cost-effective mandibular biomodels: a standardized evaluation of 3D-Printing via fused layer deposition modeling on soluble support structures.

J Stomatol Oral Maxillofac Surg 2021 Sep 15;122(4):355-360. Epub 2020 Oct 15.

Department of Cranio-Maxillo-Facial Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany; Department of Cranio-Maxillo-Facial Surgery, Hospital Osnabrück, Osnabrück, Germany.

Introduction: Medical biomodels can be used for illustration of medical conditions, preoperative planning or to facilitate pre-bending of osteosynthesis material. They have been shown to be an effective and efficient method to reduce operating time, blood loss and wound stress in cranio-maxillo-facial surgery. Lately, new time and cost-efficient 3D-printing methods have been introduced into the mass-market. The aim of this study was to establish a standardized method of evaluation and consequently evaluate Fused Layer Deposition Modeling in combination with soluble support structures for fabrication of medical biomodels regarding precision and cost-effectiveness.

Materials & Methods: Twenty-one biomodels of human mandibles equipped with measuring appliances were printed on a FLDM 3D-printers (Ultimaker 3 Extended) using a polyactate filament and a water-soluble Polyvinyl alcohol-based support structures. Precision of these models was compared to commercial, polyamide sintered models and the planning data. Production costs, printing times and post processing procedures were evaluated.

Results: Duration of printing of mandibular biomodels was between 6 h 5 min - 15 h 9 min (mean 9 h 12 min, ±2 h 25 min). The average cost of materials was €5.90 (± €1.28) per model. With an average aberrance of 0.29 mm, FLDM printing delivered a high level of accuracy. It was significantly superior to the polyamide reference models in the area of the semilunar incision, yet inferior at the coronoid process.

Conclusion: FLDM printers are able to provide very precise biomodels at very low costs. The use of using soluble support structures reduces time, costs and equipment needed for post processing procedures close to zero.
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http://dx.doi.org/10.1016/j.jormas.2020.09.018DOI Listing
September 2021

Fulfillment of patients' information needs during oral cancer treatment and its association with posttherapeutic quality of life.

Qual Life Res 2021 Jan 29;30(1):169-180. Epub 2020 Aug 29.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.

Purpose: Surgical therapy for oral cancer can lead to severe physical and psychological disorders that negatively impact patient quality of life (QoL). This study aimed to evaluate the relationship between fulfillment of patients' information needs during oral cancer treatment and patients' perception of posttherapeutic disorders influencing QoL.

Methods: A retrospective analysis of 1359 patients who were surgically treated for oral cancer using questionnaires administered during the multicenter rehabilitation study by the German-Austrian-Swiss Cooperative Group on Tumors of the Maxillofacial Region (DÖSAK). Patients and medical practitioners completed questionnaires following cancer treatment.

Results: Approximately 37% of patients felt inadequately informed about possible physical and psychological consequences of surgery. In contrast, only 16% of patients felt they were given inadequate information about the operative procedure and possible complications, and with regard to tumor diagnosis and cancer disease, only 15% of patients. Significant correlations were found between lacking information and increased perception of posttherapeutic disorders, whereas correlations with tumor-specific and operation-related parameters were markedly lower. The patients with superior QoL after treatment stated more frequently, nearly independent of individual patient characteristics, that the information that they were given prior to therapy was adequate. Information concerning possible physical and psychological consequences of an operation, however, was frequently stated to be inadequate, independent of QoL.

Conclusion: Patients whose information needs concerning the diagnosis and treatment of oral cancer are adequately fulfilled may benefit in terms of their therapeutic outcome, experiencing less perception of posttherapeutic physical and psychological disorders and a superior QoL.
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http://dx.doi.org/10.1007/s11136-020-02616-0DOI Listing
January 2021

Retrospective analysis of 15 years of horse-related maxillofacial fracture data at a major German trauma center.

Eur J Trauma Emerg Surg 2020 Jul 22. Epub 2020 Jul 22.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg Strasse 1, 30625, Hannover, Germany.

Purpose: The purpose of this study was to estimate the effect of the mechanism of trauma (fall versus kick), rider demographics, equestrian experience, protective equipment, and whether or not a horse was shod on the anatomic site of a horse-related maxillofacial fracture, operating time, postoperative complication rate, and length of hospital stay.

Methods: We retrospectively reviewed the medical records of patients treated for horse-related maxillofacial fractures at a single institution in Germany between January 2000 and March 2015. We used linear and logistic regression to test the above-mentioned variables for statistical correlations.

Results: During the study period, we treated 138 horse-related facial fractures in 71 patients. The mean patient age was 34.5 years, and 80.3% of the injuries occurred in women. Most of the maxillofacial fractures were the result of a horse kick (71.8%) when unmounted and the majority occurred in more experienced riders (70.4%). There was a significant association of wearing of protective equipment with a shorter hospital stay and lower risk of postoperative complications.

Conclusion: More education is needed in the equestrian community regarding the use of protective equipment when unmounted. Safety helmets should be redesigned to include a faceguard and be worn at all times.
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http://dx.doi.org/10.1007/s00068-020-01450-wDOI Listing
July 2020

Influence of Unilateral Cleft Lip Configuration on Long-Term Facial Averageness: A New Three-Dimensional Analysis Approach.

Facial Plast Surg Aesthet Med 2021 Mar-Apr;23(2):132-139. Epub 2020 Jul 1.

Department for Oral and Maxillofacial Surgery, Hannover Medical School, Hannover, Germany.

Concepts regarding cleft lip and palate care vary widely globally, as there is no international consensus. Consequently, institutional surveillance of cleft concepts is essential. In addition to subjective expert rankings, three-dimensional (3D) photogrammetry of the face has become the gold standard for evaluation and objective assessment of facial structures. We evaluated cleft configuration preoperatively to determine the influence thereof on the long-term facial appearance/averageness of unilateral cleft lip patients. Plaster models of the patient's labio-oral region and nose were made preoperatively, digitized, and cleft configuration assessed (cleft width, cleft-columella angle, nasal projection, heminasal width ratio, transverse lip length, labial height). Between 4 and 12 years after surgery, stereophotogrammetry (3D face scans) were captured to determine the patients' individual facial averageness index (FAI) as a deviation from the population mean, using proportion indices (PIs) of facial landmarks and reference data provided by Farkas and FaceBase. Cleft width ( = 0.77) and columella length correlated strongly with long-term facial averageness ( = 0.52). Decreasing FAI was seen with increasing patient age ( = -0.42), indicating increasing facial averageness. Other cleft properties showed weaker correlations. Cleft alveolus did not have any impact on FAI. The presented method allows objective measurement of facial appearance/averageness as well as preoperative cleft properties. It might be superior to subjective assessments of facial attractiveness/appearance. Objective cleft measurements are strong predictors for future facial averageness. Increasing averageness with growth and age suggests late corrective surgery.
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http://dx.doi.org/10.1089/fpsam.2020.0154DOI Listing
July 2021

Patient-specific implant modification for alloplastic bridging of mandibular segmental defects in head and neck surgery.

J Craniomaxillofac Surg 2020 Mar 3;48(3):315-322. Epub 2020 Feb 3.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany. Electronic address:

Displacement of the remaining mandibular segments may occur after alloplastic bridging of mandibular segmental defects using patient-specific reconstruction plates. Consequently, additional surgical devices are required for correct plate positioning. Patient-specific reconstruction plates with a conventional one beam-like design (cPSRP) have been modified by adding two flanges and giving a Y-shape to the distal ascending implant part to allow for segment positioning without using additional devices. We aimed to evaluate reconstruction results after using these modified patient-specific reconstruction plates (mPSRP). We compared the reconstruction results for mPSRP and cPSRP and evaluated mandibular segment dislocations after reconstruction using digital image analysis of the pre- and postoperative radiological data sets. Analysis showed better reconstruction results with mPSRP than with cPSRP; mean dislocation values concerning shifts and rotations of mandibular segments were lower for mPSRP (x-axis: 2.9 mm vs 1.1 mm, 4.2° vs 3.6°; y-axis: 6.0 mm vs 2.0 mm, 3.5° vs 2.8°; z-axis: 3.9 mm vs 3.3 mm, 4.2° vs 1.2°). Significant differences were found for shifts along the y-axis (p = 0.039) and rotations around the z-axis (p = 0.041). Therefore, implant design modifications with additional positioning elements could help simplify surgical reconstruction procedures and improve reconstruction in head and neck surgery.
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http://dx.doi.org/10.1016/j.jcms.2020.01.018DOI Listing
March 2020

Current Strategies in Post-traumatic Orbital Reconstruction.

J Maxillofac Oral Surg 2019 Dec 12;18(4):483-489. Epub 2019 Jun 12.

Hannover Medical School, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany.

Posttraumatic orbital reconstruction is one of the most fascinating fields in reconstructive craniomaxillofacial surgery. Hardly any other field in craniomaxillofacial surgery has changed so much in terms of diagnostics, biomaterial selection for reconstruction, surgical techniques including approaches and quality control. In particular, in the field of reconstructive orbital surgery all advances in modern medical treatment are summarized and represented. Reconstructive orbital surgery thus became the medical field spearheading all reconstructive surgical specialties in terms of use of DICOM-data, computer assistance, change towards patient-specific solutions and establishing digital workflows for adequate quality control during all phases of treatment, i.e. pre-, intra- and postoperative. With this paper, this evolutionary process shall be demonstrated as well as display the spirit of change that was necessary to optimize reconstructive orbital surgery and to improve medical care in all areas of reconstruction. Finally, reconstructive orbital surgery could prove to be a highly foreseeable field nowadays, thus giving the next generation of CMF-surgeons a huge opportunity to drive this topic further into the future.
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http://dx.doi.org/10.1007/s12663-019-01235-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6795655PMC
December 2019

Angiogenic effects of mesenchymal stem cells in combination with different scaffold materials.

Microvasc Res 2020 01 12;127:103925. Epub 2019 Sep 12.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany. Electronic address:

Tissue survival in regenerative tissue engineering requires rapid vascularization, which is influenced by scaffold material and seeded cell selection. Poly-l-lactide-co-glycolide (PLGA) and beta-tricalcium phosphate (β-TCP) are well-established biomaterials with angiogenic effects because of their material properties. Given the importance of the seeded cell type as a co-factor for vascularization, mesenchymal stem cells (MSCs) are known to have high angiogenic potential. We hypothesized that PLGA and β-TCP scaffolds seeded with MSCs would effectively induce a potent angiogenic response. Therefore, we studied the angiogenic effects after implanting PLGA and β-TCP scaffolds seeded with isogeneic MSCs in vivo. Fifty-six BALB/c mice were equally divided into seven groups and underwent implantation of the dorsal skinfold chambers. Two MSC groups were seeded on collagen-coated PLGA or β-TCP scaffolds, whereas groups 3-6 received collagen-coated or uncoated scaffolds without MSCs. No scaffold implantation was performed for group 7, which served as the control. Angiogenesis was assessed in vivo via intravital fluorescence microscopy. Angiogenic responses were noted on all scaffolds, whereupon MSC angiogenic response was significantly enhanced on days 6 and 10. Additionally, a comparison of biomaterials indicated increased angiogenic activity for β-TCP scaffolds compared with PLGA scaffolds. In conclusion, seeding β-TCP scaffolds with MSCs can accelerate vitalization and a combination of both significantly improves angiogenesis.
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http://dx.doi.org/10.1016/j.mvr.2019.103925DOI Listing
January 2020

Survival Rates According to Tumour Location in Patients With Surgically Treated Oral and Oropharyngeal Squamous Cell Carcinoma.

Anticancer Res 2019 May;39(5):2527-2533

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Hannover, Germany.

Background/aim: We evaluated survival rates in surgically-treated oral and oropharyngeal squamous cell carcinoma patients at our clinic, and determined whether survival differed by tumour locations.

Patients And Methods: In a retrospective study, tumour lesions in 1,486 patients were categorized into 6 groups according to tumour location. Patients' age, sex, tumour-node-metastasis classification, resection status, 5-year and disease-specific survival rates were statistically analysed between groups.

Results: A significantly inferior disease-specific and lower 5-year survival rates for tumours located at the base of the tongue and oropharynx, and maxilla, due to higher T-stage and incomplete resection status were shown. Cervical lymph node metastasis and distant metastatic spread were more frequently observed with base of the tongue and oropharynx lesions.

Conclusion: Attentive inspection and precise clinical examinations of specific oral and oropharyngeal regions are crucial for early diagnosis and treatment. Oral and oropharyngeal tumour locations play important roles in disease prognosis.
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http://dx.doi.org/10.21873/anticanres.13374DOI Listing
May 2019

Physical and Psychological Impairments Associated with Mucositis after Oral Cancer Treatment and Their Impact on Quality of Life.

Oncol Res Treat 2019 10;42(6):342-349. Epub 2019 Apr 10.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Hannover, Germany.

Background: Posttherapeutic mucositis is a common secondary effect of oral cancer treatment. Mucositis affects the oral mucosa, which leads to specific physical impairments in oral function and a negative impact on quality of life.

Objective: To evaluate the impairments associated with oral mucositis and their impact on posttherapeutic quality of life.

Methods: A retrospective analysis was conducted on 1,652 patients treated for oral cancer during the multicenter rehabilitation study of the German-Austrian-Swiss Cooperative Group on Tumors of the Maxillofacial Region (DÖSAK), which included 43 clinics from Germany, Austria, and Switzerland. The analysis was based on questionnaires filled out by patients following treatment.

Results: Approximately 10% of 1,652 patients included in our study had physical or psychological impairments due to increased posttreatment oral mucositis; this was mainly due to adjuvant radiotherapy or radiochemotherapy administered. Oral mucositis was significantly associated with specific physical impairments, especially xerostomia and pain (p = 0.000), which required supportive care and analgesia (p = 0.000). Additionally, impaired ingestion and speech significantly led to psychological disorders such as public avoidance behavior and social isolation (p = 0.001). Depressive coping of disease (p = 0.001) and concomitant depressive tendencies (p = 0.004) were highly associated with mucositis, which was accompanied by diminished general condition (p = 0.001), bleak future prospects (p = 0.006), and a reduction in quality of life (p = 0.002).

Conclusion: Minimizing mucositis-related impairments should be a main effort in oral cancer treatment to optimize patient outcome and improve quality of life after therapy.
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http://dx.doi.org/10.1159/000499720DOI Listing
December 2019

Ossification of the Vascular Pedicle After Microsurgical Soft Tissue Transfer of the Lateral Upper Arm Free Flap.

Ann Plast Surg 2019 12;83(6):e39-e42

From the Department for Oral and Maxillofacial Surgery.

Reconstruction of intraoral defects is one of the main aspects of head and neck cancer treatment. Since the advent of microvascular surgery in this field, free flap tissue transfer has become a common procedure, and various flaps have been described for soft tissue reconstruction. The lateral upper arm free flap is one of the most frequently used flaps for intraoral defect coverage. This article describes ossification of the corresponding vascular pedicle after soft tissue transfer with the lateral upper arm free flap and microsurgical anastomosis in oral cancer treatment. Similar findings in the context of the lateral upper arm free flap have never been reported in the literature; however, it is important for surgeons to know that pedicle ossification can occur. This knowledge may be helpful to avoid erroneous diagnosis of the ossification as a sign of tumor relapse/recurrence as well as to anticipate potential difficulties in the surgical approach in cases requiring reentry of the reconstructed region, for example, in relapse/recurrence of head and neck cancer.
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http://dx.doi.org/10.1097/SAP.0000000000001876DOI Listing
December 2019

Heterotopic bone formation in the musculus latissimus dorsi of sheep using β-tricalcium phosphate scaffolds: evaluation of different seeding techniques.

Regen Biomater 2018 Mar 27;5(2):77-84. Epub 2017 Nov 27.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, Hannover 30625, Germany and.

Osseous reconstruction of large bone defects remains a challenge in oral and maxillofacial surgery. In addition to autogenous bone grafts, which despite potential donor-site mobility still represent the gold standard in reconstructive surgery, many studies have investigated less invasive alternatives such as cultivation techniques. This study compared different types of seeding techniques on pure β-tricalcium phosphate scaffolds in terms of bone formation and ceramic resorption . Cylindrical scaffolds loaded with autologous cancellous bone, venous blood, bone marrow aspirate concentrate or extracorporeal cultivated bone marrow stromal cells were cultured in sheep on a perforator vessel of the musculus latissimus dorsi over a 6-month period. Histological and histomorphometric analyses revealed that scaffolds loaded with cancellous bone were superior at promoting heterotopic bone formation and ceramic degradation, with autogenous bone and bone marrow aspirate concentrate inducing formation of vital bone tissue. These results confirm that autologous bone constitutes the preferred source of osteoinductive and osteogenic material that can reliably induce heterotopic bone formation .
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http://dx.doi.org/10.1093/rb/rbx029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5888254PMC
March 2018

A customised digitally engineered solution for fixed dental rehabilitation in severe bone deficiency: A new innovative line extension in implant dentistry.

J Craniomaxillofac Surg 2017 Oct 3;45(10):1632-1638. Epub 2017 Aug 3.

Department of Oral and Maxillofacial Surgery (Head: Prof. Dr. Dr. Nils-Claudius Gellrich), Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.

Objectives: Numerous procedures including soft and hard tissue reconstructions are necessary to allow for final implant-borne dental rehabilitation in patients with severe alveolar atrophy or resected jaws. In these cases, customised digitally engineered patient solutions for fixed or removable dental rehabilitation provide an innovative line extension to conventional implant dentistry.

Material And Methods: A wax-up was performed on plaster models that were scanned by 3D laser. The generated stereolithographic files were then fused with the preoperative 3D imaging data. The individualised "dental" patient solutions were designed digitally and comprised a skeletonised anchorage system and a suprastructure connection system. Insertion of the implants was performed on an outpatient basis. Conventional implant-supported prosthodontic rehabilitation was performed.

Results: This digital planning algorithm can be applied to manufacture individualised patient solutions. Similar to conventional implant-supported dentures, these implants can be equipped with individual suprastructure connection systems for internal conical connection, ball-retained attachment, and external conical (telescopic) connection.

Conclusions: In patients with severe atrophy or resected jaws, particularly following ablative tumour surgery, customised digitally engineered solutions allow for an innovative, less invasive line extension to conventional implant dentistry. When conventional implant dentistry reaches its limits, they still offer a strategy for implant-borne dental rehabilitation.
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http://dx.doi.org/10.1016/j.jcms.2017.07.022DOI Listing
October 2017

Regular Dental Visits: Influence on Health-Related Quality of Life in 1,607 Patients with Oral Squamous Cell Carcinoma.

Int J Dent 2017 30;2017:9638345. Epub 2017 May 30.

Department of Cranio and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.

Background: The incidence of oral squamous cell carcinoma (OSCC) is in the top 10 of all cancer entities. Regular oral examinations by dentists play an important role in oral cancer prevention.

Methods: Patients with OSCC ( = 1,607) and physicians ( = 1,489) completed questionnaires during the DÖSAK Rehab Study. The psychosocial and functional factors collected in these questionnaires were assessed in the present study. We compared patients who visited their dentist at least once a year (group A) with those who visited their dentist less than once a year (group B).

Results: Patients in group A had significantly better health-related quality of life after tumor treatment than patients in group B. Patients in group A also had a smaller tumor size and less lymph node metastasis and lost fewer teeth during the treatment. This resulted in better prosthetic rehabilitation and better psychological status after tumor treatment.

Conclusions: Dentists play an important role in the early recognition of oral cancer. This study should encourage dentists to take a more active role in oral cancer prevention.
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http://dx.doi.org/10.1155/2017/9638345DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5468556PMC
May 2017

Neck Dissection's Burden on the Patient: Functional and Psychosocial Aspects in 1,652 Patients With Oral Squamous Cell Carcinomas.

J Oral Maxillofac Surg 2017 Apr 28;75(4):839-849. Epub 2016 Sep 28.

Medical Psychologist and Professor, Department of Medical Psychology, Ruhr University of Bochum, Bochum, Germany.

Purpose: In this study of patients with oral squamous cell carcinoma, the authors sought to clarify the functional and psychosocial harms of neck dissection (ND), which lessens quality of life.

Materials And Methods: The study included questionnaire responses from patients with oral squamous cell carcinoma (n = 1,652) and clinicians (n = 1,489), as collected in the DÖSAK Rehab Study. Psychosocial and functional factors were assessed. Functional and psychosocial outcomes in patients who did not receive ND were compared with those in patients who underwent selective supraomohyoid ND (SND), modified radical ND (MND), and radical ND (RND).

Results: Patients with ND had lower quality of life than those without ND. Burdens after SND (n = 923) were generally lesser than those after MND (n = 301) or RDN (n = 678). There were meaningful differences between the SND, MND, and RND and without-ND groups in impairments in speech intelligibility for strangers and familiar persons, ingestion and swallowing, tongue mobility, opening of the mouth, lower jaw mobility, neck mobility, and shoulder and arm movement (P < .05). Many patients with ND faced a lower functional status and negative professional and financial consequences.

Conclusions: Because of the burdens associated with ND, the decision to perform this treatment for oral squamous cell carcinoma should incorporate information on health-related quality of life and survival rates.
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http://dx.doi.org/10.1016/j.joms.2016.09.037DOI Listing
April 2017

Putative CD133+ melanoma cancer stem cells induce initial angiogenesis in vivo.

Microvasc Res 2016 Mar 2;104:46-54. Epub 2015 Dec 2.

Department of Oral and Maxillofacial Surgery, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany. Electronic address:

Tumor angiogenesis is essential for tumor growth and metastasis, and is regulated by a complex network of various types of cells, chemokines, and stimulating factors. In contrast to sprouting angiogenesis, tumor angiogenesis is also influenced by hypoxia, inflammation, and the attraction of bone-marrow-derived cells. Recently, cancer stem cells have been reported to mimic vascularization by differentiating into endothelial cells and inducing vessel formation. In this study, the influence of cancer stem cells on initial angiogenesis was evaluated for the metastatic melanoma cell line D10. Following flow cytometry, CD133+ and CD133- cells were isolated using magnetic cell separation and different cell fractions were transferred to porcine gelatin sponges, which were implanted into the dorsal skinfold chamber of immunocompromised mice. Angiogenesis was analyzed based on microvessel density over a 10-day period using in vivo fluorescence microscopy, and the results were verified using immunohistology. CD133+ D10 cells showed a significant induction of early angiogenesis in vivo, contrary to CD133- D10 cells, unsorted D10 cells, and negative control. Neovascularization was confirmed by visualizing endothelial cells by immunohistology using an anti-CD31 antibody. Because CD133+ cells are rare in clinical specimens and hardly amenable to functional assays, the D10 cell line provides a suitable model to study the angiogenic potential of putative cancer stem cells and the leukocyte-endothelial cell interaction in the dorsal skinfold chamber in vivo. This cancer stem cell model might be useful in the development and evaluation of therapeutic agents targeting tumors.
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http://dx.doi.org/10.1016/j.mvr.2015.12.001DOI Listing
March 2016

A Rare Pathology: Low-Grade Fibromyxoid Sarcoma of the Maxilla.

J Oral Maxillofac Surg 2016 Jan 25;74(1):219.e1-10. Epub 2015 Sep 25.

Consultant, Department of Oral and Maxillofacial Surgery, Hannover Medical School, Hannover, Germany.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare tumor with a benign histologic appearance and fully malignant behavior. To date, only 5 cases of LGFMS in the maxillofacial region have been reported. This report describes the case of a 16-year-old boy who was referred to the authors' hospital with an intraosseous myxofibroblastic tumor, probably of the LGFMS type, of the right maxilla. Radical resection with wide safe margins and secondary reconstruction with a free forearm flap were performed. Six-month follow-up showed no sign of recurrence or metastasis. The authors review the scientific literature and discuss different tumor locations and treatment strategies for those in the maxillofacial region. The present case is the sixth reported case of LGFMS in the maxillofacial region (intraosseous LGFMS of the maxilla), adding another facet to the literature regarding this rare soft tissue tumor.
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http://dx.doi.org/10.1016/j.joms.2015.09.018DOI Listing
January 2016

Efficacy of transcutaneous transseptal orbital decompression in treating acute retrobulbar hemorrhage and a literature review.

Craniomaxillofac Trauma Reconstr 2014 Mar 20;7(1):17-26. Epub 2013 Nov 20.

Department of Oral and Maxillofacial Surgery, Hannover Medical School.

Decreasing visual acuity secondary to orbital trauma may be caused by sudden space-occupying or expanding intraorbital lesions, including retrobulbar hemorrhage (RBH), herniation, or swelling. RBH must be diagnosed and treated immediately. This article addresses the efficacy of transcutaneous transseptal orbital decompression in a combination with a systematic review of the literature for a comparison of this method with existing treatment options. For this study the department's database was retrospectively screened for patients with acute RBH who were treated between 2009 and 2011 using the authors' approach. Patients presenting with RBH were classified into RBH classes I to III according to three different clinical and radiological manifestations of acute RBH. The efficacy of transcutaneous transseptal orbital decompression was assessed by postoperative visual acuities. The literature review was performed by using the MEDLINE database. The time period for the study was between 2009 and 2011 during which 10 patients were diagnosed with suspected RBH and 9 were treated with the authors' technique. Visual acuities were reconstituted or maintained in almost 86% of patients who were diagnosed and treated according to the authors approach and who survived initial trauma. It was concluded that transcutaneous transseptal orbital decompression provides an efficient and rapid approach for treating patients with acute RBH. By distinguishing three different manifestations of acute RBH, the authors present a diagnostic tool that may facilitate classification of RBH and determination of treatment options.
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http://dx.doi.org/10.1055/s-0033-1356754DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3931771PMC
March 2014

Diffuse large B-cell lymphoma subgroups have distinct genetic profiles that influence tumor biology and improve gene-expression-based survival prediction.

Blood 2005 Nov 26;106(9):3183-90. Epub 2005 Jul 26.

Department of Pathology and Hematology Hospital Clinic, University of Barcelona, Spain.

Gene-expression profiling has identified 3 major subgroups of diffuse large B-cell lymphoma (DLBCL): germinal center B-cell-like (GCB), activated B-cell-like (ABC), and primary mediastinal DLBCL (PMBCL). Using comparative genomic hybridization (CGH), we investigated the genetic alterations of 224 cases of untreated DLBCL (87 GCB-DLBCL, 77 ABC-DLBCL, 19 PMBCL, and 41 unclassified DLBCL) previously characterized by gene-expression profiling. The DLBCL subgroups differed significantly in the frequency of particular chromosomal aberrations. ABC-DLBCL had frequent trisomy 3, gains of 3q and 18q21-q22, and losses of 6q21-q22, whereas GCB-DLBCL had frequent gains of 12q12, and PMBCL had gains of 9p21-pter and 2p14-p16. Parallel analysis of CGH alterations, locus-specific gene-expression profiles, and global gene-expression signatures revealed that DNA amplifications and gains had a substantial impact on the expression of genes in the involved chromosomal regions, and some genes were overexpressed in a DLBCL subgroup-specific fashion. Unexpectedly, specific chromosomal alterations were associated with significant changes in gene-expression signatures that reflect various aspects of lymphoma cell biology as well as the host response to the lymphoma. In addition, gains involving the chromosomal region 3p11-p12 provided prognostic information that was statistically independent of the previously defined gene-expression-based survival model, thereby improving its predictive power.
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http://dx.doi.org/10.1182/blood-2005-04-1399DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1895326PMC
November 2005
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