Fortschritte der Kiefer- und Gesichts-Chirurgie最新文献

A series of 922 fractures of the mandibular body (median-paramedian, horizontal ramus and mandibular angle) was treated within a 10 years period from January 1984 to December 1993 by an uniform treatment method. It consisted of compression plating with bicortical screw anchorage and intraoral approach, thus avoiding any outer scar and facial nerve damage. Postoperatively intermaxillary fixation was not used in any of these cases. A solid bony union was achieved in more than 99% of the cases. Major complications as osteomyelitis and non union were observed in 8 cases (0.86%). Minor complications of soft tissue infections without interference of fracture healing as haematomas, soft tissue abscesses and suture dehiscence were observed in 6.1%. A separate analysis of 352 mandibular angle fractures, which are regarded as particularly problematic, showed a frequency of severe complications (osteomyelitis and nonunion) of 0.85%. This is comparable with the frequency of complications of 0.86% within the total series. In this largest series of compression plating via intraoral approach, which has ever been published, the technique again has proved its significance as a standard procedure for the treatment of mandibular fractures.

The accuracy of sonographic imaging of displaced mandibular fractures has been investigated experimentally. Mandibles taken from fresh pig cadavers have been osteotomized and fracture displacement according to the three types of dislocation has been performed. The bony fragments were connected by threads to enable reproducible ranges of displacement. The investigations were performed with 7.5, 10 and 13 MHz linear arrays. Longitudinal and lateral displacements from 1 to 10 mm and axial displacements from 1 degree to 5 degrees were investigated. We could find, that B-mode-sonography is very sensitive to detect the direction of displacement in mandibular fractures, if at least 1 mm of displacement exists. The measurements of the amount of displacement show, that the difference of the sonographic measurements and the real existing displacement depends on the direction of the displacement and the chosen frequency of examination. It is independent from the amount of displacement. The mean error of all examination is less than 0.4 mm. The greatest difference between the real displacement and the measured one is found in axial displacement from 1 degree to 3 degrees. The results show, that B-mode sonography is a reliable method detecting displaced fractures of the mandible and the clinical application of the method can be recommended. The sonographic detection of nondisplaced fractures is a problem which needs further technical development.

We do not advocate routine open reduction in subcondylar fractures, but there are some indications for surgical treatments. If we have decided for open reduction, the risks must be weighed against the benefits. If we are not sure, that the condyle is in a correct position, we avoid rigid internal fixation and we prefer only a temporary stabilization with resorbable Polydioxanone, Polylactide or autologous bone-pins. In non oblique fractures, we recommend only open reduction without further internal fixation. The advantage is that the condyle has the ability to move into a physiologic position and there is no need to remove metal implants in a second operation, the disadvantage is that we cannot avoid MMF and functional therapy, but our experience shows that the functional therapy can be shortened. Resorbable- and bone-pins could not take place of miniplates or traction-screws, but in selected cases, they could enlarge the surgical treatment in subcondylar fractures.

80 patients with 83 fractures of the mandibular angle were treated by lag screw fixation. The screws were placed through a transoral incision with transbuccal trochar instrumentation. No maxillomandibular fixation was used. Complications occurred in 12 fractures (14%), of which 5 (6%) required secondary surgical intervention. In all cases bony union was achieved 6 months postoperatively. Indications and advantages of the technique are discussed.

During a period of 8 years (1986-1994) we treated 183 patients with mandibular fractures. Within this period we changed our treatment protocol from the rigid internal fixation (AO/ASIF method) to monocortical noncompression miniplates. The complications of 127 AO/ASIF cases versus 41 miniplate cases were studied. Complications mostly consisted in dehiscences. Comparing the two methods we found more complications (19.5%) when the AO plate is applicated via an intraoral approach. After extraoral AO treatment and after monocortical miniplates there was no significant difference concerning our complications (8.1% versus 7.3%).

Between 1980 and 1993 81 patients with a combined mandibular body and bilateral mandibular condyle fractures underwent open reduction and internal fixation of the mandibular body. The following methods were used: 29 x miniplate osteosynthesis, 28 x maxiplate osteosynthesis, 13 x lag screws, 10 x combinations and once titanium mesh. Reoperations because of occlusal disturbances were necessary in two cases of miniplate fixation, in one case of maxiplate fixation and in one case of lag screw fixation. In 1994 28 patients were reviewed. Posterior crossbite as operative sequela was noted in 2 (out of 14) patients after miniplate osteosynthesis, in 3 (out of 9) patients with maxiplate osteosynthesis, in 1 (out of 4) patients with combined miniplate and lag screw fixation and in 0 (out of 3) cases with lag screws. In cases of oblique mandibular body fractures we recommend the lag screw technique. Maxiplate osteosynthesis is more troublesome and more difficult in comparison with miniplate osteosynthesis. Therefore we recommend the miniplate osteosynthesis for the remaining types of mandibular body fracture and if needed the mandibular condyle.

We report about our experience in five patients who suffered from a mandibular micrognathia after ancylosis of the temporomandibular joint. At first the ancylosis was removed using a costochondral graft. About one year later, the mandible was cut by an osteotomy behind the last visible toothbud and a distractor was inserted. The mandible was to a slide overcorrection. This has to be taken into account to compensate a certain relapse. At first we used an unidirectional device, for one and a half years we have used a bidirectional device (Normed from Tuttlingen/Germany) which enables us to correct mandibular hypoplasias more adequately. Up to now our experience shows, that gradual callus-distraction leads to stable normalization of mandibular hypoplasias. Functional problems concerning chewing and speech are solved, the dramatical improvement of the profile of the face may avoid psycho-social problems for these patients.

The Ultrasound technique as an image producing procedure for fractures of the mandibular collum is outlined with physical theory and clinical examples. Advantages and disadvantages are compared and it is stated that a part of all patients with fractures might have a benefit from this method. Mentally handicapped patients, pregnant women and all sorts of fidgety patients will profit by the ultrasound investigation as the only way to ascertain the bone-fracture. There is necessity to relate the sonogram to a conventional X-ray picture whenever it is possible, for the procedure is suited to prove the fracture, not to exclude it.

The question whether- and if by which means-operative reconstruction of condylar process fractures is appropriate is still unresolved. This study was initiated to compare osteosynthesis of low dislocated and/or luxated condylar fractures by means of miniplates or lag screws according to Eckelt. 22 patients participated, 16 being treated with miniplate osteosynthesis, 6 with lag screws. Investigation concentrated on the parameters TMJ-function (side shift in dynamic and static occlusion, maximum interincisal distance, impairment of pro- and laterotrusion), radiologic post-operative fragment position, intra- and postoperative complications, and evaluation by the patients. Miniplate osteosynthesis showed better results leading in 80% to an unimpaired TMJ function compared to 50% of the lag screw group. Miniplate osteosynthesis was performed faster. No intra- or postoperative problems occurred in contrary to the lag screw, where one fracture of the screw intra- and one post-operatively were noted. Even if the numbers are too small for statistical calculations, trends are shown favouring miniplate osteosynthesis for operative reconstruction of condylar fractures.