Ali Gbara

Major Mandibular Surgical Procedures as an Indication for Intraoperative Imaging

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

Distraction osteogenesis in secondary microsurgical mandible reconstruction : Report of seven cases

INTRODUCTION Fibula, ilium and scapula are the preferred donor areas for vascularised bone grafts. For secondary mandibular reconstruction, however, compromises often have to be made as a result of the poor quality of the covering soft tissue and recipient vessels especially in irradiated patients. Callus distraction osteogenesis is a complementary method for optimising the intermaxillary relationship and the facial profile from an aesthetic point of view. MATERIALS AND METHODS Thirteen distractions were performed in seven patients following microsurgical mandibular reconstruction over a period of 4 years, all by the same surgeon. Intra-oral distraction devices were predominantly applied. After a 7-day healing period, the callus distraction was begun, involving two advisements per day of 0.5mm each. The distraction devices were removed after a consolidation phase of 4-5 months. RESULTS Ten of the 13 distractions were uneventful with an average bone lengthening of 20mm, retained after a follow-up time of 6-47 months (average 27 months). The intermaxillary relationship and the facial profile were improved in all cases. Distraction plate fractures, screw loosening or absence of new bone formation were the complications encountered in the other three patients. CONCLUSION Regarding the high complication rate, a successful outcome cannot be expected with greater certainty. Thus the indication should be stringent when including this procedure within the possible treatment alternatives available to the clinician.

Multidirektionale winkelstabile Osteosynthese für die Versorgung von Gesichtsschädelfrakturen

ZusammenfassungFür die Versorgung von Gesichtsschädelfrakturen wurde ein multidirektionales winkelstabiles Osteosynthesesystem entwickelt. Dieser Fixateur interne wurde am Gesichtsschädel biomechanisch getestet. Der Vergleich mit herkömmlichen Osteosynthesesystemen in einer Kadavertestung zeigte eine Stabilitätserhöhung von bis zu 40%, wobei das winkelstabile System kleiner dimensioniert war und eine geringere Schraubenzahl aufwies.AbstractA new multidirectional angularly stable interlocking plate system was developed for the surgical treatment of midfacial fractures. This system was tested on the visceral cranium in a biomechanical study on human cadavers. When compared to conventional plate osteosynthesis systems, a 40% higher degree of stability with a marked increase in the loading tolerance was observed. It is remarkable that the fixation is performed in conjunction with a reduction of the number of screws.

Titanmagnete auf Implantaten als Hilfsmittel zur Rehabilitation nach Tumorbehandlung

Zusammenfassung Häufig brauchen Patienten nach einer Tumorresektion eine sich anschließende ästhetische und funktionelle Rekonstruktion mit prothetischer Rehabilitation. Oft steht nur wenig Platz für die Implantation zur Verfügung. Implantatlänge und Durchmesser müssen deshalb reduziert werden. Es kann zu einer Veränderung der Biomechanik mit evtl. Überlastung der Implantate kommen. Wir untersuchten 52 rekonstruierte Tumorpatienten mit insgesamt 189 Implantaten. Mit Hilfe von Titanmagneten können wir dabei ein neues Konzept vorstellen, um auch bei Problemfällen eine überwiegend zufriedenstellende prothetische Versorgung nach der Rekonstruktion zu erreichen. Summary After the resection of a tumor, many patients need a reconstruction with hard and soft tissue and also with sufficient dentures. Often, only little space is available for the implantation. Implant length and diameter have to be reduced, and the result is a change in the biomechanics with a possible mechanical overloading of the implant. We examined 52 tumor patients undergoing reconstruction with 189 implants. A new concept involving attachment with the help of magnets is presented, offering a satisfactory solution in these difficult cases after tumor resection and reconstruction.