28 results on '"Alexander-Nicolai Zeller"'
Search Results
2. Novel approach for treating challenging implant-borne maxillary dental rehabilitation cases of cleft lip and palate: a retrospective study
- Author
-
Björn Rahlf, Philippe Korn, Alexander-Nicolai Zeller, Simon Spalthoff, Philipp Jehn, Fritjof Lentge, and Nils-Claudius Gellrich
- Subjects
Cleft lip and palate ,IPS-preprosthetic® ,Implant-borne dental rehabilitation ,3D-technology ,Selective laser melting ,CAD/CAM ,Medicine ,Dentistry ,RK1-715 - Abstract
Abstract Purpose Dental restoration in cleft lip and palate (CLP) patients is demanding and often results in bone loss and dental implant failure. Furthermore, unfavorable conditions of hard and soft tissues as well as skeletal deformities aggravate surgical and dental treatment. Therefore, this study was designed to assess the feasibility of using a new type of patient-specific implant (IPS-preprosthetic®) in CLP patients. Methods Of the 63 patients who received a IPS-preprosthetic® implant in the Department of Oral and Maxillofacial Surgery at the Hannover Medical School, Germany, six patients were treated for a CLP deformity with significant soft and hard tissue impairment. Two patients were partially edentulous, whereas four patients were edentulous for the maxilla. All implants were inserted in a single-step outpatient surgery and were followed up for up to 40 months. Results Within the observation period, no implant failed and no screw loosening or change in stability of the implant to recipient site occurred (mean number of screws: 21). This study demonstrates, for the first time, the efficient use of a one-piece multivector screw primarily retained a stable patient-specific implant for implant-borne prosthodontic rehabilitation of CLP patients with deformities and challenging initial situations. Conclusions IPS-preprosthetic® implants offer a novel approach to implant dentistry treatment protocols, especially in difficult cases of unusual anatomy, even when previous conventional treatment fails.
- Published
- 2022
- Full Text
- View/download PDF
3. Accuracy of Guided Surgery and Real-Time Navigation in Temporomandibular Joint Replacement Surgery
- Author
-
Michael-Tobias Neuhaus, Alexander-Nicolai Zeller, Alexander K. Bartella, Anna K. Sander, Bernd Lethaus, and Rüdiger M. Zimmerer
- Subjects
temporomandibular joint disorders ,total joint replacement ,virtual surgical planning ,guided surgery ,real-time navigation ,3D-printing ,Dentistry ,RK1-715 - Abstract
Background: Sophisticated guided surgery has not been implemented into total joint replacement-surgery (TJR) of the temporomandibular joint (TMJ) so far. Design and in-house manufacturing of a new advanced drilling guide with vector and length control for a typical TJR fossa component are described in this in vitro study, and its accuracy/utilization was evaluated and compared with those of intraoperative real-time navigation and already available standard drilling guides. Methods: Skull base segmentations of five CT-datasets from different patients were used to design drilling guides with vector and length control according to virtual surgical planning (VSP) for the TJR of the TMJ. Stereolithographic models of the skull bases were printed three times for each case. Three groups were formed to compare our newly designed advanced drilling guide with a standard drilling guide and drill-tracking by real-time navigation. The deviation of screw head position, screw length and vector in the lateral skull base have been evaluated (n = 72). Results: There was no difference in the screw head position between all three groups. The deviation of vector and length was significantly lower with the use of the advanced drilling guide compared with standard guide and navigation. However, no benefit in terms of accuracy on the lateral skull base by the use of real-time navigation could be observed. Conclusion: Since guided surgery is standard in implant dentistry and other CMF reconstructions, this new approach can be introduced into clinical practice soon, in order to increase accuracy and patient safety.
- Published
- 2021
- Full Text
- View/download PDF
4. Postoperative quality of life and therapy-related impairments of oral cancer in relation to time–distance since treatment
- Author
-
Philipp Jehn, Philippe Korn, Gertrud Krüskemper, Nils-Claudius Gellrich, Fabian Matthias Eckstein, Frank Tavassol, Fritjof Lentge, Alexander-Nicolai Zeller, Simon Spalthoff, and Michael-Tobias Neuhaus
- Subjects
Pediatrics ,medicine.medical_specialty ,Oncology (nursing) ,business.industry ,media_common.quotation_subject ,Cancer therapy ,Cancer ,medicine.disease ,Oncology ,Quality of life ,Surveys and Questionnaires ,Quality of Life ,Carcinoma, Squamous Cell ,medicine ,Breathing ,Humans ,Mouth Neoplasms ,Neoplasm Recurrence, Local ,Worry ,Surgical treatment ,business ,Depression (differential diagnoses) ,Retrospective Studies ,Rehabilitation Study ,media_common - Abstract
Oral cancer resection can cause physical and psychological impairments that influence the quality of life (QoL). Depending on the postoperative time–distance, the occurrence and intensity of these impairments may change. We evaluated the sequelae and changes in therapy-related impairments during the postoperative course to detect associations between the time since surgery and the presence of disorders. Data from a questionnaire completed by 1359 patients who underwent surgical treatment of oral squamous cell carcinoma and were involved in a multicenter rehabilitation study of the German–Austrian–Swiss Cooperative Group on Tumors of the Maxillofacial Region (DOSAK) that included 43 oral and maxillofacial clinics in Germany, Austria, and Switzerland were retrospectively analyzed. Physical impairments, including those in appearance, mouth opening ability, ability to smell, gastric disorders, mandible mobility, breathing, and shoulder/arm mobility, were significantly associated with and increased with time–distance since surgery. Esthetic appearance most strongly correlated with the highest perception of worsening. Regarding psychological disorders, worry about tumor recurrence, depression, and worse prospects were significantly associated. Among the postoperative sequelae, fear of tumor recurrence decreased continuously; however, depression and worse prospects increased. The general QoL did not significantly differ overall during the postoperative course. Therapy-related impairments change during the postoperative course based on the time–distance since surgery. The general QoL may not markedly vary; however, single impairments, to some extent, can increase or decrease. Continuous adaptation of supportive cancer therapy is required during follow-up to sufficiently address individual treatment needs.
- Published
- 2021
- Full Text
- View/download PDF
5. Intraoperative real-time navigation and intraoperative three-dimensional imaging for patient-specific total temporomandibular joint replacement
- Author
-
Rüdiger Zimmerer, Michael-Tobias Neuhaus, Nils-Claudius Gellrich, Bernd Lethaus, Philipp Jehn, and Alexander-Nicolai Zeller
- Subjects
Joint Prosthesis ,medicine.medical_treatment ,Prosthesis ,03 medical and health sciences ,Imaging, Three-Dimensional ,0302 clinical medicine ,medicine ,Humans ,Retrospective Studies ,Orthodontics ,Computer-assisted surgery ,Temporomandibular Joint ,business.industry ,030206 dentistry ,Temporomandibular joint ,Skull ,Dissection ,medicine.anatomical_structure ,Three dimensional imaging ,Surgery, Computer-Assisted ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Radiological weapon ,Surgery ,Implant ,Oral Surgery ,business - Abstract
Customized solutions for replacement of the temporomandibular joint (TMJ) along with surgical guides enable precise and fast transfer of the virtual plan to the patient. However, these guides lack information on screw vectors and length, and well-defined borders for bony resections towards the medial skull base. This retrospective study was performed to investigate the feasibility and benefit of real-time navigation and intraoperative three-dimensional imaging during total TMJ replacement (TJR), as well as patient clinical outcomes. Between 2016 and 2020, 26 customized prostheses were implanted in 21 patients either with or without real-time navigation and instrument tracking. The clinical, surgical, radiological, and navigational data were analysed. The accuracy of navigation registration with instrument tracking, precision of screw insertion, and implant and screw positions were analysed by fusion of the virtual plan and surgical outcome. Real-time navigation aided orientation during lateral skull base dissection and resection. However, the results of real-time navigation-aided drilling were inconclusive regarding vector and length control. At a mean 15.3±3.0 months of follow-up, average mouth opening had improved from 21.69±2.80mm to 36.40±1.25mm; the average pain score decreased from 6.18±0.74 to 1.06±0.52. Thus, intraoperative real-time navigation for TJR assists lateral skull base dissection and resection.
- Published
- 2021
- Full Text
- View/download PDF
6. Komplexe Rekonstruktionen im Gesichts- und im Schädelbereich
- Author
-
Alexander-Nicolai Zeller, Philippe Korn, Nils-Claudius Gellrich, Fritjof Lentge, and Fabian Matthias Eckstein
- Subjects
Gynecology ,medicine.medical_specialty ,business.industry ,Emergency Medicine ,medicine ,Orthopedics and Sports Medicine ,Surgery ,business ,medicine.disease ,Polytrauma - Abstract
Die posttraumatische Rekonstruktion des Hirn- und Gesichtsschadels stellt neben der onkologischen Chirurgie, der Chirurgie kraniofazialer Fehlbildungen und der zahnarztlichen Chirurgie einen wesentlichen Bestandteil der modernen Mund‑, Kiefer- und Gesichtschirurgie dar. Aufgrund der komplexen Anatomie des Gesichtsschadels sowie der masgeblichen asthetischen und funktionellen Anspruche an seine Rekonstruktion stellt die rekonstruktive Traumachirurgie in diesem Bereich hochste Anforderungen an den Behandler. Dies ist umso mehr der Fall, wenn die definitive mund-, kiefer- und gesichtschirurgische Versorgung zugunsten anderer lebensbedrohlicher Verletzungen teils erst mit deutlichen Verzogerungen erfolgen kann. Um diesen Voraussetzungen Rechnung zu tragen, kamen in der Mund‑, Kiefer- und Gesichtschirurgie bereits fruh Errungenschaften der modernen Biomedizintechnik wie die intraoperative Echtzeitnavigation, die computerassistierte Planung und die computerassistierte Herstellung (CAD/CAM) von patientenspezifischen Biomodellen und Implantaten zum Einsatz. In Kombination mit der intraoperativen 3D-Bildgebung ergibt sich aus diesen Methoden ein auf den individuellen Patienten ausgelegter Behandlungspfad, der in jedem Schritt direkt auf seine Qualitat gepruft wird und so das bestmogliche Ergebnis fur den Patienten sicherstellt. Die Nutzung dieser Technologien reicht so heute weit uber die ursprunglichen Indikationen im Bereich der Orbitarekonstruktion und der Wiederherstellung knocherner Defekte mit einfacher Geometrie – Kalottendefekte – hinaus. So konnen heute auch komplexeste panfaziale Frakturen asthetisch und funktionell, z. B. mithilfe digitalisierter Vorplanung und individualisierter Schadeldach‑, Orbita- und Jochbeinimplantate sowie totaler Kiefergelenkendoprothesen, rekonstruiert werden.
- Published
- 2021
- Full Text
- View/download PDF
7. Self-centering second-generation patient-specific functionalized implants for deep orbital reconstruction
- Author
-
Michael Neuhaus, Nora Gessler, Sandra Skade, Alexander-Nicolai Zeller, Rüdiger Zimmerer, Nils-Claudius Gellrich, Philipp Jehn, and Philippe Korn
- Subjects
Enophthalmos ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,In patient ,030223 otorhinolaryngology ,Orbital Fracture ,Orbital Fractures ,Intraoperative imaging ,Retrospective Studies ,Orthodontics ,business.industry ,030206 dentistry ,Plastic Surgery Procedures ,Patient specific ,Otorhinolaryngology ,Orbital reconstruction ,Surgery ,Orbital cavity ,Implant ,Oral Surgery ,medicine.symptom ,business ,Orbital Implants - Abstract
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.
- Published
- 2021
- Full Text
- View/download PDF
8. Training in oral and maxillofacial surgery in Germany - Residents’ satisfaction and future challenges
- Author
-
Michael Ehrenfeld, Andreas Pabst, Daniel G. E. Thiem, Alexander K. Bartella, Alexander Nicolai Zeller, Jürgen Hoffmann, Lukas B. Seifert, and Fabian M Beiglboeck
- Subjects
Adult ,Male ,medicine.medical_specialty ,education ,Personal Satisfaction ,Nationwide survey ,Training (civil) ,German ,03 medical and health sciences ,0302 clinical medicine ,General satisfaction ,Germany ,Surveys and Questionnaires ,Humans ,Medicine ,business.industry ,Internship and Residency ,030206 dentistry ,Surgery, Oral ,language.human_language ,Family life ,Otorhinolaryngology ,Satisfaction rate ,030220 oncology & carcinogenesis ,Family medicine ,language ,Oral and maxillofacial surgery ,Female ,Surgery ,Gender gap ,Oral Surgery ,business - Abstract
The aim of this study was to analyze the current situation of trainees in OMFS in a nationwide survey at German universities and teaching hospitals. A questionnaire about their training in OMFS and discrimination, gender (in-)equality, and reconcilability of work and family life was sent to many OMFS residents in Germany. Seventy-five questionnaires were included. The average age of the participants was 32.15 years (± 0.75 years); 47 participants were male, 22 female, and 3 "diverse". The participants' overall satisfaction rate was good. Training concepts existed in most of the teaching hospitals (54.67%). 8.11% of the participants stated discrimination existed against men while, 24.32% agreed that discrimination existed against women. Stating that discrimination against women exists, it was associated with female gender (p 0.001), being married (p = 0.042), and not aiming for further academic degrees (p = 0.009). Overall, the training situation in Germany seems structured in most teaching hospitals. Apart from the residents' general satisfaction with the training concepts, there seems to be a matter of concern regarding discrimination especially against women and the reconcilability of work and family life in OMFS training. Furthering the establishment of structured training concepts might be useful to overcome these issues in the course of training in OMFS.
- Published
- 2021
- Full Text
- View/download PDF
9. Patientenspezifische Implantate in der Mund-, Kiefer- und Gesichtschirurgie
- Author
-
Philippe Korn, Frank Tavassol, Björn Rahlf, Alexander-Nicolai Zeller, Philipp Jehn, Fabian Matthias Eckstein, Nils-Claudius Gellrich, and Simon Spalthoff
- Subjects
Gynecology ,03 medical and health sciences ,medicine.medical_specialty ,0302 clinical medicine ,media_common.quotation_subject ,medicine ,030206 dentistry ,Art ,030223 otorhinolaryngology ,media_common - Abstract
ZusammenfassungDie Verwendung von patientenspezifischen Implantaten zur Rekonstruktion von Defekten des Schädels und der Kiefer hat sich in den letzten Jahren als Standard in der Mund-, Kiefer- und Gesichtschirurgie etabliert. Anfänglich wurden die zum Einsatz kommenden Implantate intraoperativ direkt an die Defektsituation angepasst. Mit dem Fortschritt in der 3-dimensionalen Bildgebung und im Zuge der zunehmenden Digitalisierung wurden zunächst patientenspezifische 3-D-gedruckte Biomodelle zur direkten Anpassung konfektionierter Implantate im Operationssaal verwendet. Heute kommen vermehrt Implantate zum Einsatz, die im Rahmen eines computerassistierten Designprozesses (CAD) und einer anschließenden computerassistierten Herstellung (CAM) vollständig digital geplant werden. Anfangs war die Verwendung dieser CAD/CAM-gefertigten Implantate auf Defekte mit einfachen Geometrien, wie die Rekonstruktion des Schädeldachs, beschränkt. Durch Fortschritte in der digitalen Planung und der digital gestützten Herstellung können CAD/CAM-gefertigte patientenspezifische Implantate heute auch zur Versorgung komplexer Defektsituationen im präventiven und funktionalisierten Design verwendet werden. Neben der Orbitarekonstruktion und der alloplastischen Rekonstruktion des Unterkiefers kommen individualisierte Implantate auch zur komplexen dentalen Rehabilitation und funktionellen Wiederherstellung der Kiefergelenke zum Einsatz.
- Published
- 2021
- Full Text
- View/download PDF
10. Fulfillment of patients’ information needs during oral cancer treatment and its association with posttherapeutic quality of life
- Author
-
Michael-Tobias Neuhaus, Philippe Korn, Frank Tavassol, Nils-Claudius Gellrich, Alexander-Nicolai Zeller, Rüdiger Zimmerer, Gertrud Krüskemper, Philipp Jehn, and Simon Spalthoff
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Information needs ,Disease ,Young Adult ,03 medical and health sciences ,0302 clinical medicine ,Quality of life ,Surveys and Questionnaires ,medicine ,Humans ,Child ,Association (psychology) ,Aged ,Retrospective Studies ,Rehabilitation Study ,Aged, 80 and over ,business.industry ,030503 health policy & services ,Public health ,Infant, Newborn ,Public Health, Environmental and Occupational Health ,Infant ,Cancer ,Middle Aged ,medicine.disease ,Cancer treatment ,Child, Preschool ,030220 oncology & carcinogenesis ,Quality of Life ,Physical therapy ,Female ,Mouth Neoplasms ,0305 other medical science ,business - Abstract
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. 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 (DOSAK). Patients and medical practitioners completed questionnaires following cancer treatment. 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. 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.
- Published
- 2020
- Full Text
- View/download PDF
11. Prelamination of the Radial Forearm Free Flap Using Free Full-Thickness Eyelid Skin Grafts: A New Approach for Intraoral Defect Reconstruction
- Author
-
Philipp Jehn, Nils-Claudius Gellrich, Holger Moysich, Alexander-Nicolai Zeller, Fritjof Lentge, Frank Tavassol, Simon Spalthoff, and Philippe Korn
- Subjects
Adult ,Male ,Forearm ,Eyelids ,Humans ,Surgery ,Skin Transplantation ,Middle Aged ,Plastic Surgery Procedures ,Free Tissue Flaps ,Aged - Abstract
Free flap transfer for reconstruction of intraoral defects is a common procedure in oral and maxillofacial surgery. For tumor-related defects, the radial forearm flap is widely used for soft tissue restoration. However, transfer of free skin grafts to the donor site region is often required for wound closure after free flap harvesting, resulting in esthetic disturbances due to shrinkage of the grafted skin, attendant scarring, or mismatches in skin texture or color. Furthermore, free flap transfer may result in hair follicle transfer into the oral cavity, causing unfavorable intraoral hair growth in adult men in particular. Free flap prelamination can help reduce the potential disadvantages of free flaps, in terms of both flap design and size and donor site morbidity. For surgical treatment of oral cancer in middle-aged and elderly patients, eyelid dermatochalasis may present as a comorbidity leading to esthetic impairments or, in cases involving the upper eyelid, even a reduced field of view. In these cases, bilateral blepharoplasty can reduce the excess eyelid skin. The present study is the first to attempt to use excised skin after bilateral blepharoplasty as full-thickness skin grafts for radial forearm free flap prelamination. This approach combined surgical therapy of eyelid dermatochalasis with free flap prelamination, thereby avoiding the need to harvest free skin grafts from other anatomically healthy regions to close the donor site defect and preventing the accompanying disadvantages. The reconstruction results and clinical outcomes of patients revealed that radial forearm free flap prelamination using bilateral free full-thickness eyelid skin grafts was an easy and feasible method for intraoral defect reconstruction. In particular, this approach could avoid intraoral hair growth and additional skin grafting from other healthy anatomical regions, yielding good esthetic and functional results at the flap's recipient and donor sites.
- Published
- 2022
12. Gender-specific differences concerning psychosocial aspects and functional impairments that influence quality of life in oral cancer treatment
- Author
-
Philipp Jehn, Sabine Swantje Linsen, Alexander-Nicolai Zeller, Fabian Matthias Eckstein, Michael-Tobias Neuhaus, Nils-Claudius Gellrich, Gertrud Krüskemper, Fritjof Lentge, Simon Spalthoff, and Philippe Korn
- Subjects
Male ,Oncology ,Adaptation, Psychological ,Carcinoma, Squamous Cell ,Quality of Life ,Humans ,Female ,Mouth Neoplasms ,Neoplasm Recurrence, Local - Abstract
Patients with oral cancer have gender-specific differences with respect to health-related quality of life (HRQoL) and psychosocial variables (PV). The aim of the present study was to evaluate HRQoL and PV outcomes in patients treated for oral squamous cell carcinoma.Data of 1234 patients were collected from a multicenter rehabilitation study of the German-Austrian-Swiss Cooperative Group on Tumours of the Maxillofacial Region (DÖSAK). Patient characteristics, oncological variables, post-treatment impairments, general quality of life (QoL), and PV (coping strategies, control beliefs, personal traits, perceived social support, depression, anxiety, and fear of tumor recurrence) were recorded.After treatment, HRQoL was similar between genders concerning general QoL, but men experienced significantly more treatment-related functional impairments influencing HRQoL. PV revealed gender-specific coping strategies, with women reporting significantly more "depressive coping," "religiosity," "fatalistic externality," and higher "social burden." Owing to their religious coping strategies, fatalistic attitude, and perceived higher social integration, women demonstrated superior disease acceptance, despite higher depression, anxiety, and lower psychosocial resilience. Conversely, men reported more introverted personal traits and lower social integration.Interventions during oral cancer treatment should address PV and have gender-specific elements to improve HRQoL after therapy.
- Published
- 2021
13. Managing the severely atrophic maxilla: Farewell to zygomatic implants and extensive augmentations?
- Author
-
Philippe Korn, Nils-Claudius Gellrich, Simon Spalthoff, Philipp Jehn, Fabian Eckstein, Fritjof Lentge, Alexander-Nicolai Zeller, and Björn Rahlf
- Subjects
Dental Implants ,Zygoma ,Otorhinolaryngology ,Dental Implantation, Endosseous ,Maxilla ,Humans ,Jaw, Edentulous ,Surgery ,Dental Prosthesis, Implant-Supported ,Oral Surgery ,Atrophy ,Follow-Up Studies ,Retrospective Studies - Abstract
Dental rehabilitation of severe atrophic upper jaws remains challenging. A new generation of subperiosteally placed and rigid multi-vector bone-anchored patient-specific implants proposes an innovative line extension in implant dentistry. This single-center retrospective study focused on treating severely atrophic maxillae using these implants.All patients who were treated with a patient-specific implant (IPS Implant® Preprosthetic, KLS-Martin, Tuttlingen, Germany) at Hannover Medical School due to severe atrophy of the maxilla who had no history of malignancy, cleft lip or palate, or trauma were evaluated regarding implant stability and prosthetic restoration, as well as complications.Out of a total of 58 inserted implants, 13 implants in 10 patients, which were placed to treat a severely atrophic upper jaw, were identified. The mean follow-up period was 8.2 months (1-29 months). All implants were clinically stable over the entire period. All patients with an observation period of over 2 months received prosthetics for restoration. Minor complications, screw fractures, infection, and exposure of the framework were observed, but these did not lead to failure.This initial follow-up suggests that this new generation of implants represents a valuable treatment alternative, especially for patients with a history of failed dental implant placement. Larger numbers of cases and longer observation periods are required to confirm our findings.
- Published
- 2021
14. Minimal bone resorption after open treatment of mandibular condylar head fractures
- Author
-
Michael-Tobias Neuhaus, Nils-Claudius Gellrich, Alexander-Nicolai Zeller, Alexander Karl-Heinz Bartella, Anna Katharina Sander, Bernd Lethaus, Dirk Halama, and Rüdiger Martin Zimmerer
- Subjects
stomatognathic system - Abstract
Open treatment of condylar base and neck fractures is widely recommended, whereas treatment of condylar head fractures is still controversial and just is removal of osteosynthesis material. In this study, bone resorption and remodelling after open treatment of condylar head fractures were three-dimensionally (3D) assessed and correlated with clinical parameters in a medium follow-up. Of 18 patients with 25 condylar head fractures who underwent open reduction and internal fixation, clinical data and cone beam computed tomography (CBCT) datasets were analysed. Condylar processes were segmented in the postoperative and follow-up CBCT scans. Volumetric and linear changes were measured using a sophisticated 3D-algorithm. In the course after surgery, patients function and pain improved significantly. Low rates of postoperative complications were observed. All 3D measurements showed no significant bone resorption during the follow-up period. Open reduction of condylar head fractures leads to good patients outcomes and low rates of long-term complications. This study underlines the feasibility and importance of open treatment of condylar head fractures and may help to spread its acceptance as the preferred treatment option.
- Published
- 2021
- Full Text
- View/download PDF
15. Patient-specific implant modification for alloplastic bridging of mandibular segmental defects in head and neck surgery
- Author
-
Rüdiger Zimmerer, Simon Spalthoff, Alexander-Nicolai Zeller, Philippe Korn, Frank Tavassol, Nils-Claudius Gellrich, Philipp Jehn, and Jan Dittmann
- Subjects
Orthodontics ,Bridging (networking) ,business.industry ,Implant design ,Mandible ,030206 dentistry ,Patient specific implant ,Mandibular Neoplasms ,03 medical and health sciences ,0302 clinical medicine ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Digital image analysis ,Head and neck surgery ,Humans ,Medicine ,Surgery ,Implant ,Mandibular Reconstruction ,Oral Surgery ,business ,Bone Plates - Abstract
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.
- Published
- 2020
- Full Text
- View/download PDF
16. Patient-Specific Mandibular Reconstruction Plates Increase Accuracy and Long-Term Stability in Immediate Alloplastic Reconstruction of Segmental Mandibular Defects
- Author
-
Amit Dhawan, Rüdiger Zimmerer, Michael-Tobias Neuhaus, Alexander-Nicolai Zeller, Nils-Claudius Gellrich, L. V. M. Weissbach, Fabian Matthias Eckstein, and M. Rana
- Subjects
medicine.medical_specialty ,Functional impairment ,CAD/CAM ,03 medical and health sciences ,Ablative surgery ,0302 clinical medicine ,Mandibular reconstruction ,medicine ,Orthodontics ,Alloplastic reconstruction ,Osteosynthesis ,business.industry ,Mandible ,030206 dentistry ,Patient specific ,Coronoid process ,Plastic surgery ,Fracture ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Oral and maxillofacial surgery ,Original Article ,Surgery ,Oral Surgery ,business - Abstract
Objectives The aim of the current study was to evaluate potential differences in the accuracy of mandibular reconstruction and long-term stability, with respect to different reconstructive procedures. Methods In total, 42 patients who had undergone primary segmental mandibular resection with immediate alloplastic reconstruction, with either manually pre-bent or patient-specific mandibular reconstruction plates (PSMRP), were included in this study. Mandibular dimensions, in terms of six clinically relevant distances (capitulum [most lateral points], capitulum [most medial points], incisura [most caudal points], mandibular foramina, coronoid process [most cranial points], dorsal tip of the mandible closest to the gonion point) determined from tomographic images, were compared prior to, and after surgery. Results Dimensional alterations were significantly more often found when conventionally bent titanium reconstruction plates were used. These occurred in the area of the coronoid process (p = 0.014). Plate fractures were significantly (p = 0.022) more often found within the manually pre-bent group than within the PSMRP group (17%/0%). Conclusion The results suggest that the use of PSMRP may prevent rotation of the proximal mandibular segment, thus avoiding functional impairment. In addition, the use of PSMRP may potentially enhance the long-term stability of alloplastic reconstructions.
- Published
- 2020
- Full Text
- View/download PDF
17. [Complex reconstructions in the facial and cranial regions]
- Author
-
Nils-Claudius, Gellrich, Fabian Matthias, Eckstein, Fritjof, Lentge, Alexander-Nicolai, Zeller, and Philippe, Korn
- Subjects
Imaging, Three-Dimensional ,Surgery, Computer-Assisted ,Skull ,Computer-Aided Design ,Humans ,Plastic Surgery Procedures ,Patient Care Planning - Abstract
Posttraumatic reconstruction of the neurocranium and viscerocranium is an essential part of modern oral and maxillofacial surgery, in addition to oncological surgery, surgery of congenital craniofacial deformities and dental surgery. Due to the complex anatomy of the facial skull and significant esthetic and functional demands on its reconstruction, reconstructive trauma surgery in this area places the highest demands on the surgeon. This is all the more true if definitive craniomaxillofacial surgical treatment can sometimes only be performed with considerable delays for the benefit of other life-threatening injuries. In order to take these prerequisites into account, achievements of modern biomedical technology, such as intraoperative real-time navigation, computer-assisted planning and computer-assisted manufacturing (CAD/CAM) of patient-specific biomodels and implants, came up early for use in oral and maxillofacial surgery. In combination with intraoperative three-dimensional imaging, these methods result in a treatment pathway tailored to the individual patient, which is directly checked for quality at every step and thus ensures the best possible result for the patient. The use of these technologies extends far beyond the original indications in the area of orbital reconstruction and restoration of bony defects with simple geometry, such as skull defects. Nowadays, even the most complex pan-facial fractures can be restored esthetically and functionally by means of digitalized preliminary planning and individualized skull, orbital and zygomatic implants as well as total temporomandibular joint prostheses.Die posttraumatische Rekonstruktion des Hirn- und Gesichtsschädels stellt neben der onkologischen Chirurgie, der Chirurgie kraniofazialer Fehlbildungen und der zahnärztlichen Chirurgie einen wesentlichen Bestandteil der modernen Mund‑, Kiefer- und Gesichtschirurgie dar. Aufgrund der komplexen Anatomie des Gesichtsschädels sowie der maßgeblichen ästhetischen und funktionellen Ansprüche an seine Rekonstruktion stellt die rekonstruktive Traumachirurgie in diesem Bereich höchste Anforderungen an den Behandler. Dies ist umso mehr der Fall, wenn die definitive mund-, kiefer- und gesichtschirurgische Versorgung zugunsten anderer lebensbedrohlicher Verletzungen teils erst mit deutlichen Verzögerungen erfolgen kann. Um diesen Voraussetzungen Rechnung zu tragen, kamen in der Mund‑, Kiefer- und Gesichtschirurgie bereits früh Errungenschaften der modernen Biomedizintechnik wie die intraoperative Echtzeitnavigation, die computerassistierte Planung und die computerassistierte Herstellung (CAD/CAM) von patientenspezifischen Biomodellen und Implantaten zum Einsatz. In Kombination mit der intraoperativen 3D-Bildgebung ergibt sich aus diesen Methoden ein auf den individuellen Patienten ausgelegter Behandlungspfad, der in jedem Schritt direkt auf seine Qualität geprüft wird und so das bestmögliche Ergebnis für den Patienten sicherstellt. Die Nutzung dieser Technologien reicht so heute weit über die ursprünglichen Indikationen im Bereich der Orbitarekonstruktion und der Wiederherstellung knöcherner Defekte mit einfacher Geometrie – Kalottendefekte – hinaus. So können heute auch komplexeste panfaziale Frakturen ästhetisch und funktionell, z. B. mithilfe digitalisierter Vorplanung und individualisierter Schädeldach‑, Orbita- und Jochbeinimplantate sowie totaler Kiefergelenkendoprothesen, rekonstruiert werden.
- Published
- 2021
18. Changes in emergency patient presentation to a maxillofacial surgery department during the COVID-19 pandemic
- Author
-
Alexander Nicolai Zeller, Fritjof Lentge, Simon Spalthoff, Philippe Korn, Björn Rahlf, and Philipp Jehn
- Subjects
medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,MEDLINE ,Article ,03 medical and health sciences ,0302 clinical medicine ,Pandemic ,medicine ,Humans ,Maxillofacial surgery department ,Pandemics ,business.industry ,SARS-CoV-2 ,General surgery ,Medical school ,COVID-19 ,030206 dentistry ,Surgery, Oral ,Patient volume ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Oral and maxillofacial surgery ,Surgery ,Oral Surgery ,Presentation (obstetrics) ,business ,Emergency Service, Hospital - Abstract
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(2019) < 0.001, p(2018) < 0.01), 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(2019) < 0.001, p(2018) < 0.001), while the proportion of patients who presented with trauma was significantly higher (p(2019) < 0.001, p(2018) < 0.001). 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. Conclusion 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.
- Published
- 2021
19. CAD/CAM-based referencing aids to reduce preoperative radiation exposure for intraoperative navigation
- Author
-
Sina Springhetti, Rüdiger Zimmerer, Nils-Claudius Gellrich, Michael-Tobias Neuhaus, Alexander-Nicolai Zeller, Frank Tavassol, and Björn Rahlf
- Subjects
Models, Anatomic ,Tessellation (computer graphics) ,Stereotactic surgery ,Computer science ,Biophysics ,CAD ,03 medical and health sciences ,0302 clinical medicine ,Imaging, Three-Dimensional ,stomatognathic system ,Preoperative radiation ,Humans ,Computer vision ,Intraoperative navigation ,business.industry ,Navigation system ,030206 dentistry ,Cone-Beam Computed Tomography ,Radiation Exposure ,Computer Science Applications ,Splints ,030220 oncology & carcinogenesis ,Computer-Aided Design ,Surgery ,Artificial intelligence ,Tomography ,business ,Tomography, X-Ray Computed - Abstract
BACKGROUND All intraoperative navigation systems need a referencing procedure prior to utilization, usually requiring an additional computed tomography (CT) or cone beam computed tomograph (CBCT) scan. As new techniques in the field of Computer-aided design / Computer-aided manufacturing (CAD/CAM) have evolved, it seemed favourable to develop a new referencing method not relying on additional CT or CBCT scans. METHODS A digital maxillary dental scan was used to create a referencing splint by CAD/CAM containing four reference points. By matching scanned dental model and initial trauma-CT, the splints position and thus the reference points were digitally simulated. These splints data were imported into the navigation system in Standard Tessellation Language (STL) format. These data were also 3D printed and the resulting piece was placed on the anatomical models' teeth. The methods accuracy was then assessed in vitro. CONCLUSION Our method for referencing of intraoperative navigation can be feasible to avoid an additional CT or CBCT prior to navigation.
- Published
- 2021
20. The influence of the SARS-CoV-2 pandemic on oral and maxillofacial surgery: a nationwide survey among 54 hospitals and 240 private practices in Germany
- Author
-
Matthias Schneider, Robert Sader, Michael Ehrenfeld, Andreas Pabst, Jörg-Ulf Wiegner, Jürgen Hoffmann, and Alexander Nicolai Zeller
- Subjects
Hygiene measures ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Private Practice ,Economic burden ,Patient care ,Nationwide survey ,Health administration ,03 medical and health sciences ,0302 clinical medicine ,Germany ,Surveys and Questionnaires ,Pandemic ,Humans ,Medicine ,Pandemics ,General Dentistry ,health care economics and organizations ,SARS-CoV-2 ,business.industry ,Dental procedures ,COVID-19 ,030206 dentistry ,medicine.disease ,Surgery, Oral ,Hospitals ,Coronavirus ,Personal protection equipment ,030220 oncology & carcinogenesis ,Oral and maxillofacial surgery ,Original Article ,Medical emergency ,business - Abstract
Objective The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has created hitherto unknown challenges for healthcare systems and patient care. This study aimed to analyze its influence on patient care and healthcare management in oral and maxillofacial surgery (OMFS) in Germany. Materials and methods A nationwide survey of the German Association of Oral and Maxillofacial Surgery was performed. Individual questionnaires containing 10 questions for university as well as non-university hospitals and 15 questions for private practices (PPs) for OMFS were created to collect data for patient numbers and surgical procedures conducted, usage of personal protection equipment (PPE), SARS-CoV-2 tests, and economic aspects. Results Fifty-four hospitals and 240 PPs participated in the study. The reduction in ward capacities and number of surgical procedures ranged from 17 to 78%. PPE consisted of standard surgical masks (58% hospitals, 64% PPs) and FFP2/N95/KN95 respirators (45% hospitals, 48% PPs). Preoperative SARS-CoV-2 tests were more frequently performed in hospitals (34% vs 2%). At PPs, turnover for medical and dental procedures billed to the public insurance had reduced to 58.81% and 62.43%, respectively, of the corresponding values for 2019, and 58.75% of the PPs had applied for short-time allowances. Conclusion With the exception of some elective procedures, primary patient care in OMFS has been assured during the pandemic. However, the immense economic burden on hospitals and PPs cannot be conclusively assessed at this point. Clinical relevance For OMFS, the German healthcare system has shown the ability to adapt to emergency situations such as the SARS-CoV-2 pandemic. Adequate surgical capacities in OMFS are necessary even during pandemics.
- Published
- 2021
- Full Text
- View/download PDF
21. Endoscopically Assisted Treatment of Condylar Base and Neck Fractures: A Single Institution Analysis of Outcomes and Complications
- Author
-
Lena Desch, Alexander-Nicolai Zeller, Amit Dhawan, Michael-Tobias Neuhaus, Philipp Jehn, Rüdiger Zimmerer, and Nils-Claudius Gellrich
- Subjects
medicine.medical_specialty ,Osteosynthesis ,business.industry ,medicine.medical_treatment ,Postoperative complication ,030206 dentistry ,Condyle ,Surgery ,03 medical and health sciences ,Plastic surgery ,0302 clinical medicine ,Otorhinolaryngology ,medicine ,Oral and maxillofacial surgery ,Internal fixation ,Original Article ,Oral Surgery ,030223 otorhinolaryngology ,business ,Reduction (orthopedic surgery) - Abstract
BACKGROUND: Conservative treatment, including observation and closed treatment, as well as open reduction and internal fixation are existing options for treating condylar process fractures. Extraoral approaches are widely preferred for open reduction and internal fixation. Transoral access for condylar base and neck fractures is not yet commonly used as it is technically demanding and requires special equipment. PURPOSE: In this study, the transoral endoscopically assisted approach is described, and its outcomes and complications were investigated. Imaging data and clinical records of 187 patients with condylar process fractures, treated via endoscopically assisted transoral approach between 2007 and 2017 were analyzed. Parameters included diagnosis and fracture classification, treatment, osteosynthesis configuration and postoperative complications. RESULTS: Early complications, including infection, transient postoperative malocclusion, pain and limited mouth opening, occurred in 35 patients (18.7%). Late onset complications, such as screw loosening were documented in only 4 patients (2.1%). Revision surgery following postoperative 3D imaging was required in only 3 cases (1.6%). Fragment length ranged from 15.5 to 38.3 mm. In 57.7% of patients with condylar fragment length 15 mm with low postoperative complication and revision rates.
- Published
- 2020
22. Influence of Unilateral Cleft Lip Configuration on Long-Term Facial Averageness: A New Three-Dimensional Analysis Approach
- Author
-
Michael-Tobias Neuhaus, Frank Tavassol, Philipp Jehn, Rüdiger Zimmerer, Alexander-Nicolai Zeller, and Nils-Claudius Gellrich
- Subjects
Male ,Three dimensional analysis ,Esthetics ,Cleft Lip ,Corrective surgery ,Objective assessment ,Imaging, Three-Dimensional ,Patient age ,Preoperative Care ,Medicine ,Humans ,Postoperative Period ,Child ,Retrospective Studies ,Orthodontics ,Population mean ,business.industry ,Objective measurement ,Infant ,Plastic Surgery Procedures ,stomatognathic diseases ,Treatment Outcome ,Averageness ,Facial Asymmetry ,Child, Preschool ,Photogrammetry ,FaceBase ,Preoperative Period ,Surgery ,Female ,Anatomic Landmarks ,business ,Follow-Up Studies - Abstract
Background: 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. Methods: 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. Results: Cleft width (r = 0.77) and columella length correlated strongly with long-term facial averageness (r = 0.52). Decreasing FAI was seen with increasing patient age (r = -0.42), indicating increasing facial averageness. Other cleft properties showed weaker correlations. Cleft alveolus did not have any impact on FAI. Conclusions: 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.
- Published
- 2020
23. Endoscopic-assisted reduction and internal fixation of mandibular condyle process fractures – a retrospective analysis of 356 patients
- Author
-
Alexander-Nicolai Zeller, Rüdiger Zimmerer, Jan Dittmann, Nils-Claudius Gellrich, L. Boeckmann, Michael-Tobias Neuhaus, Simon Spalthoff, and K. Zibelius
- Subjects
Orthodontics ,Otorhinolaryngology ,business.industry ,medicine.medical_treatment ,Endoscopic assisted ,Retrospective analysis ,Medicine ,Internal fixation ,Surgery ,Oral Surgery ,business ,Condyle ,Reduction (orthopedic surgery) - Published
- 2019
- Full Text
- View/download PDF
24. DEEP orbital reconstruction using self-centering custom made second generation functionalized orbital implants
- Author
-
Nils-Claudius Gellrich, Rüdiger Zimmerer, Michael-Tobias Neuhaus, and Alexander-Nicolai Zeller
- Subjects
Otorhinolaryngology ,Orbital reconstruction ,business.industry ,Medicine ,Surgery ,Oral Surgery ,business ,Biomedical engineering ,Orbital implants - Published
- 2019
- Full Text
- View/download PDF
25. Nasolabial Flap Improves Healing in Medication-Related Osteonecrosis of the Jaw
- Author
-
Alexander-Nicolai Zeller, Nils-Claudius Gellrich, T. Muecke, Juliana Lemound, André Eckardt, and Jürgen Lichtenstein
- Subjects
Male ,medicine.medical_specialty ,Side effect ,medicine.medical_treatment ,Dentistry ,Nose ,Surgical Flaps ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Aged ,Retrospective Studies ,Wound Healing ,business.industry ,Orthognathic Surgical Procedures ,Retrospective cohort study ,030206 dentistry ,Perioperative ,Decortication ,Bisphosphonate ,medicine.disease ,Mucoperiosteal Flap ,Lip ,Surgery ,Otorhinolaryngology ,030220 oncology & carcinogenesis ,Bisphosphonate-Associated Osteonecrosis of the Jaw ,Female ,Oral Surgery ,Osteonecrosis of the jaw ,business ,Complication - Abstract
Medication-related osteonecrosis of the jaw (MRONJ) is an adverse side effect of antiresorptive and antiangiogenic therapeutic agents that is difficult to treat owing to its high relapse rate. The aim of the present study was to determine whether patients with MRONJ treated using decortication and a nasolabial flap compared with those who underwent decortication with mucoperiosteal flaps have better outcomes regarding stable wound closure.Two groups of patients with MRONJ and intraoral exposed bone were evaluated in a cohort clinical study retrospectively. The primary predictor variable was the treatment group. The experimental group used the nasolabial flap for wound closure, and the control group used the mucoperiosteal flap for closure. The outcome variable was successful wound closure defined as a symptomless and closed wound after at least 12 months. Other study variables included factors such as perioperative drug holiday, duration of postoperative oral antibiotic administration, and postoperative use of nasogastric feeding tubes. Cox proportional hazard regression analysis and Kaplan-Meier curves were used to determine the factors independently associated with the dependent variable. The Mann-Whitney U test and χBoth groups showed similar demographics. The 16 study patients receiving nasolabial flaps had a mean age of 69.9 years, and the 16 control patients receiving mucoperiosteal flaps had a mean age of 71.8 years. Both groups included 10 women and 6 men. Of the 16 patients in each group, 15 had received a bisphosphonate and 1, monoclonal antibody therapy. All evaluated patients underwent combined treatment, including decortication and intravenous antibiotics. Of the 16 patients receiving nasolabial flaps, symptomless intact wound closure was achieved in 68.8%. Of the 16 patients with mucoperiosteal closure, 18.7% achieved wound closure, with 81.2% developing a relapse of MRONJ, a statistically significant difference (P .001). No statistically significant differences were found between the 2 groups in the demographic variables. The mean interval to relapse for the experimental and control groups was 13.6 ± 7.8 and 8.2 ± 7.9 months, respectively (P = .017).MRONJ is a complication of antiosteoclastic treatment of mostly oncologic, palliative patients, which requires a very methodical approach to surgical treatment. A variety of different methods have been reported. The use of nasolabial flaps can be considered as a highly reliable option for coverage the bone wound with less morbidity than microvascular free flaps and better long-term results compared with mucoperiosteal flaps.
- Published
- 2016
26. Application of a customized 3D printed reduction aid after external fixation of the femur and tibia: Technical note
- Author
-
Majeed Rana, Alexander-Nicolai Zeller, Christian Krettek, Nils-Claudius Gellrich, Mohamed Omar, and Emannouil Liodakis
- Subjects
medicine.medical_specialty ,LONG BONE FRACTURE ,External Fixators ,Computer science ,medicine.medical_treatment ,Long bone ,Biophysics ,03 medical and health sciences ,External fixation ,DICOM ,0302 clinical medicine ,Fracture Fixation ,medicine ,Humans ,Femur ,Tibia ,Reduction (orthopedic surgery) ,Orthodontics ,Fracture Healing ,030222 orthopedics ,030208 emergency & critical care medicine ,Technical note ,Computer Science Applications ,Surgery ,medicine.anatomical_structure ,Printing, Three-Dimensional ,Tomography, X-Ray Computed ,Femoral Fractures ,Algorithms ,Software - Abstract
Background To construct a fracture-specific reduction aid by means of virtual reduction technology and 3D printing to reduce malreduced, externally fixed, long bone fractures. Technique Following application of an external fixator to a malreduced long bone fracture, we performed postoperative computed tomography to visualise the fragments and their position relative to Schanz screws. DICOM data were transferred to 3D planning software, and the fracture was then virtually reduced. Subsequently, a reduction aid was designed to cover the Schanz screws in such a way that it would maintain the position of the new fragments. Following 3D printing, the solid reduction aid could be applied onto the Schanz screws. The reduction aid fit only in the reduced position of the fracture, thus maintaining correct bone alignment. Conclusion Our reduction technique can be applied during the temporary external fixation period on the preexisting external fixator or as a reduction aid during definitive treatment.
- Published
- 2016
27. 3D-Printed Simulation Device for Orbital Surgery
- Author
-
Juliana Lemound, Thorsten Enno Lichtenstein, Majeed Rana, Alexander Nicolai Zeller, Maximilian E. H. Wagner, Juergen Thomas Lichtenstein, and Nils-Claudius Gellrich
- Subjects
Adult ,Male ,Models, Anatomic ,Models, Educational ,Education ,03 medical and health sciences ,0302 clinical medicine ,Imaging, Three-Dimensional ,Orbital Diseases ,Medicine ,Humans ,Simulation Training ,Simulation ,Haptic technology ,Fixation (histology) ,Orthodontics ,business.industry ,Navigation system ,Soft tissue ,Usability ,030206 dentistry ,Plastic Surgery Procedures ,Orbit ,Surgery, Computer-Assisted ,Printing, Three-Dimensional ,030221 ophthalmology & optometry ,Oral and maxillofacial surgery ,Surgery ,Female ,Implant ,Clinical Competence ,Educational Measurement ,business - Abstract
Objectives Orbital surgery is a challenging procedure because of its complex anatomy. Training could especially benefit from dedicated study models. The currently available devices lack sufficient anatomical representation and realistic soft tissue properties. Hence, we developed a 3D-printed simulation device for orbital surgery with tactual (haptic) correct simulation of all relevant anatomical structures. Design, Setting, and Participants Based on computed tomography scans collected from patients treated in a third referral center, the hard and soft tissue were segmented and virtually processed to generate a 3D-model of the orbit. Hard tissue was then physically realized by 3D-printing. The soft tissue was manufactured by a composite silicone model of the nucleus and the surrounding tissue over a negative mold model also generated by 3D-printing. The final model was evaluated by a group of 5 trainees in oral and maxillofacial surgery (1) and a group of 5 consultants (2). All participants were asked to reconstruct an isolated orbital floor defect with a titanium implant. A stereotactic navigation system was available to all participants. Their experience was evaluated for haptic realism, correct representation of surgical approach, general handling of model, insertion of implant into the orbit, placement and fixation of implant, and usability of navigated control. The items were evaluated via nonparametric statistics (1 [poor]-5 [good]). Results Group 1 gave an average mark of 4.0 (±0.9) versus 4.6 (±0.6) by group 2. The haptics were rated as 3.6 (±1.1) [1] and 4.2 (±0.8) [2]. The surgical approach was graded 3.7 (±1.2) [1] and 4.0 (±1.0) [2]. Handling of the models was rated 3.5 (±1.1) [1] and 4 (±0.7) [2]. The insertion of the implants was marked as 3.7 (±0.8) [1] and 4.2 (±0.8) [2]. Fixation of the implants was also perceived to be realistic with 3.6 (±0.9) [1] and 4.2 (±0.45) [2]. Lastly, surgical navigation was rated 3.8 (±0.8) [1] and 4.6 (±0.56) [2]. Conclusion In this project, all relevant hard and soft tissue characteristics of orbital anatomy could be realized. Moreover, it was possible to demonstrate that the entire workflow of an orbital procedure may be simulated. Hence, using this model training expenses may be reduced and patient security could be enhanced.
- Published
- 2016
28. A systematic examination of the bone destruction pattern of the two-shot technique
- Author
-
Alexander Nicolai Zeller, Constantin von See, Majeed Rana, Carsten Stoetzer, Marcus Stoetzer, Alexander A. Hanke, and Nils-Claudius Gellrich
- Subjects
Full metal jacket bullet ,medicine.diagnostic_test ,full metal jacket ,business.industry ,lcsh:Medical emergencies. Critical care. Intensive care. First aid ,Ballistics ,Single shot ,Computed tomography ,lcsh:RC86-88.9 ,Stopping power ,Optics ,two-shot technique ,Maximum diameter ,Shot (pellet) ,Emergency Medicine ,medicine ,Original Article ,Terminal ballistics ,business - Abstract
Introduction: The two-shot technique is an effective stopping power method. The precise mechanisms of action on the bone and soft-tissue structures of the skull; however, remain largely unclear. The aim of this study is to compare the terminal ballistics of the two-shot and single-shot techniques. Materials and Methods: 40 fresh pigs′ heads were randomly divided into 4 groups (n = 10). Either a single shot or two shots were fired at each head with a full metal jacket or a semi-jacketed bullet. Using thin-layer computed tomography and photography, the diameter of the destruction pattern and the fractures along the bullet path were then imaged and assessed. Results: A single shot fired with a full metal jacket bullet causes minor lateral destruction along the bullet path. With two shots fired with a full metal jacket bullet, however, the maximum diameter of the bullet path is significantly greater (P < 0.05) than it is with a single shot fired with a full metal jacket bullet. In contrast, the maximum diameter with a semi-jacketed bullet is similar with the single-shot and two-shot techniques. Conclusion: With the two-shot technique, a full metal jacket bullet causes a destruction pattern that is comparable to that of a single shot fired with a semi-jacketed bullet.
- Published
- 2014
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.