Fortschritte der Kiefer- und Gesichts-Chirurgie最新文献

39 condylar mandibular fractures were examined by magnetic resonance imaging (MRI) within the first 12 hours after trauma prior to therapy. A new classification has been applied on the traumatic disc displacements. Three types A, B, C can be distinguished. Type A means no displacement in relation to the condylar fragment and the fossa. Type B means a displacement in the transversal plane exceeding the physiologic range of movement. Type C means displacement in the sagittal as well as in the transversal plane which exceeds the physiologic range of movement of the disc. The classified type of displacement could not be correlated exactly with dislocation and position of the bony fragments. Therefore the type of displacement cannot be predicted from conventional radiographs. Three cases of evident rupture of the disc in the biconcave zone could be shown by MRI. This kind of displacement has not been represented in the classification yet. In a presented case a rupture of the disc had been depicted preoperatively and the disc could be repaired via an preauricular approach. By means of MRI surgeons in future are able to pay more attention to the traumatology and reconstructive surgery of the temporomandibular disc.

A sample of 91 patients who had suffered from condylar fractures in the years 1970-1977 could be followed up. The mean follow up period was 19.8 years. As a prognostic relevant parameter the patient's age at the time of the accident as well as the type of the fracture where taken into account. Clinically young (8-11 years at the time of the accident) patient's with no or low grade dislocation showed the best results. Almost 36% of the patients with high grade dislocation or luxation presented measurable pathological changes during function. The condylar movement was assessed by using 3D-optoelectronic measurement. Despite severe radiographic alterations and hindered condylar translation in cases with high grade dislocation or luxation, mouth opening was not restricted in the majority of the patients. It seems that the lack of condylar translation is compensated by extensive rotation.

For the registration, documentation and evaluation of patient data in cranio-maxillo-facial (cmf) trauma surgery a Windows-based application front end for relational data base systems (RDBS) has been developed. A simple-to-learn, easily reconfigurable user interface can be adjusted to the dynamically changing needs of individual departments. A graphical user interface (GUI) eases the entry of complex information like fracture positions, the location of implanted osteosynthesis material, etc. The new program also simplifies the daily routine documentation tasks. Being linked to a Hospital Information System (HIS) it makes use of the patients' individual base data stored there. Statistical data for various studies can be extracted from the database. The program has been successfully tested on a collective of 1.178 cmf trauma patients. Predefined analyses can be generated now by the simple click of a button for various case selections. New users learn to operate the program in a very short time.

The present study was designed to investigate biomechanical and clinical changes in the mandibular complex by means of finite element analysis. An analytical model developed from human native mandibles was used for this model, CT image data were transferred to a computer, and an edge extraction program generated the cross-section of bone by specifying a range of CT values for each slice. Pixel data from the CT scan were converted into a vector of points (x, y, z) which can specify the boundaries of bone. Lateral surfaces are defined by stacking up the slices and making use of the vectorized data. The constructed model was used as input data for the finite element analysis. The models were solved for stresses and forces. The highest principal stresses occurred at the bite point, anterior aspects of the coronoid processes, symphyseal region, and right and left sides of the mandibular corpus. For further investigation muscular structures have to be integrated to establish a model, which can be analysed under multivariate aspects.

Transcranial magnetic stimulation is a new method for objective evaluation of the facial nerve without constraints for the patient. By the first time, especially cortical lesions can be detected objectively. Using this method, a permanent disturbance of the ramus marginalis mandibularis after operative treatment of fractures of the mandibular condyle could be certainly excluded. Therefore, because of the clear presentation and the possibility of enlargement, the deep submandibular approach, using a correct operative technique, can be strictly recommended.

Immediate live-saving emergency treatment of patients with heavily communited and partially defective mandibles by airway intubation, control of haemorhage and primary treatment of wounds necessarily must be followed by a staged concept of treatment for the functional and aesthetic rehabilitation of hard and soft tissue in order to enable the patient to survive not only biologically but also socially. Out of 384 patients with surgically treated mandibular fractures, 120 had multiple fractures, 24 heavily comminuted fractures and 6 sustained vast defects. All multiple and communited fractures could be treated successfully by an intraoral approach using function-orientated miniplate-osteosynthesis and in 30 cases functionally stable plates. In patients having sustained vast avulsions of soft and hard tissue, immediate emergency-revascularisation was well to the fore. In cases of tissue destruction, primarily the position of the jaw stumps was secured by plates and reconstruction was done in the early secondary stage using composed microvascularly transferred scapular flaps.