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At the present time the vascularised bone graft is the best procedure for reconstruction of mandibular defects in poor recipient tissues. We obtained 23 drill biopsies from different regions of vascularised bone transplants during the removal of the osteosynthesis plates from 14 patients who had poor recipient tissues. For comparison, we took five biopsies from the native iliac crest and eight biopsies from six patients with avascular bone transfer into unimpaired surrounding tissues. Microradiographs of the bone preparations were used for a computerised semi-automatic morphometric analysis. We evaluated the volumetric density (VV, %) and the mean trabecular diameter (D-TRAB, micron). In the central regions, the revascularised transplants decreased in volumetric density and in mean trabecular diameter. Compared with the average values of iliac crest bone, the avascular grafts increased in both parameters. The revascularised grafts showed significantly lower volumetric density and significantly lower mean trabecular diameters in the central regions than in the regions near to the mandibular stump. The avascular grafts actually showed the reverse effect. The results are discussed with particular reference to the quality of the recipient tissues, to the maintenance of graft viability, to functional stress, and to the design of the transplant.

Differing views on the nutritional status of revascularized bone in animal studies and in human transfer have been expressed. Normal viability is reported as well as single cell necrosis and devitalized areas and, finally, necrosis of the complete graft. From 19 patients with revascularized bone transfer into injured recipient tissues, we obtained 32 drill biopsies out of the centre of the graft and near the mandibular stump during the removal of the osteosynthesis plates. The histological preparations were examined for bone viability. In 58% of all patients, there occurred partial necroses in the grafted bone and in 26% single cell necroses; 16% of the transplants maintained normal viability. The areas with disturbed nutrition were found more frequently in peripheral areas than in central regions of the graft (p < 0.05, chi 2 test). The overall graft failure rate was 6.8%. The results of this clinical study are discussed with particular reference to the technical procedure, the recipient tissue quality, and the design of the graft. The indication for using revascularized bone transfer in difficult local conditions of the recipient tissues has been confirmed. The viability of the grafts cannot always be maintained entirely. The particular risk to the viability of the graft in the peripheral regions requires careful technical procedures.

Summary The importance of preoperative digital substraction angiography (DSA) in revascularized tissue transfer in the maxillofacial area is demonstrated on the basis of 53 flaps: In 7 cases DSA revealed results which influenced the therapeutic procedure. Compared to conventional methods of vascular diagnosis, DSA has considerable advantages.

Die vergleichende Untersuchung seitlicher Fernrontgenbilder von 81 Probanden mitAngle-Klasse I und regularem Gesichtsschadelaufbau und 120 Patienten, die eine skelettale Progenie bei einerAngle-Klasse-III-Okklusion hatten, ergab, das die “Gesamtlange C” des Unterkiefers (Abstand zwischen dem Kondylus und dem knochernen Kinn) diagnostisch verwertbare signifikante Unterschiede aufweist. Entgegen der Erwartung erlaubt die Grose des sogenannten “Achsenwinkels C” (Winkel zwischen Gesamtlange C und NSe) keine Unterscheidung zwischen diesen beiden Patientengruppen. Die grosere Gesamtlange des Unterkiefers bei Progenie resultiert im wesentlichen aus einer Vergroserung des Gonionwinkels und der Verlangerung des horizontalen Astes. Die “Gesamtlange” reprasentiert die Verhaltnisse des Unterkiefers kephalometrisch offensichtlich besser als die Berucksichtigung der einzelnen Daten fur den Unterkieferkorper, den aufsteigenden Ast und den Gonionwinkel.

Summary In the management of recent fractures of the zygomatic bone and arch we prefer transcutaneous repositioning with a sharp hook. If additional fixation is necessary, wire sutures are used. The advantages of osteosynthesis with wire suturing and the treatment of simultaneous fracture of the orbital floor are presented and discussed.

The cause of most fracture gap infections is either a lack of or inadequate primary management. It is therefore imperative that jaw fractures be handled initially by an oral and maxillofacial surgeon. Surgical revision and absolute immobilization are essential in cases of osteomyelitis following mandibular fracture. In special cases, additional deposition of gentamycin-PMMA spheres and autologous osteoplasty may be necessary.

Endosseus implantation is sometimes inadvisable if the bony structures are fragile. Therefore subperiosteal implantation of porous and dense hydroxyapatite ceramic implants on the unreamed parietal bone of four dogs was studied. During the investigated period of 14 weeks to 10 months the implant wassurrounded by newly formed bone which grew up against the edges of the implant and penetrated the pores. A direct contact without a connective tissue layer formed between bone and hydroxyapatite. Few osseous lamellae developed on the side of the implant adjacent to the periosteum.

For the temporary reconstruction of defects in mandibular continuity various methods are possible. Allentheses which are covered by soft tissue have considerable advantages over methods employing an enoral or transcutaneous approach. Plate and screws enable the surgeon to reconstruct a topographically correct position of the resection stumps of the mandible and the dissected muscles. Postoperative dysfunction is thus reduced and following plastic-reconstructive surgery is facilitated.

Special metal devices can be suited for a temporary alloplasty and for the fixation and stabilization of fractured bone structures. Due to their good electroconductivity, however, metals tend to corrode by electrochemical processes. Special alloys are manufactured for surgical purposes. Because of their composition and homogeneity, these alloys are claimed to be electroenergetically inactive and chemically resistant. However, this holds true only if the passive surface layer is intact. Because the surface layer in steel alloys is only 1/200 000 mm thick, the question arises, whether it can act as a barrier under biological conditions. Repeatedly, metallotic damage to the surrounding tissue and fracture of the plates have been reported (frank and Zitter, 1971; Schuster, 1970, 1975; Munzenberg et al., 1972). The question arises, to what extent corrosive processes account for these problems.

In 4 Jahren konnten bei 204 Patienten 251 totale Hydroxylapatitaugmentationen im Ober- und Unterkiefer durchgefuhrt werden. Dabei kommen immer die gleiche Operationsmethode und das gleiche Granulat zur Anwendung. Diese Vorgehensweise und eine kontinuierliche Nachuntersuchung der Patienten dienen im Rahmen der systematischen Studie dem Erarbeiten von Aussagen uber die prothetische Relevanz der Alloplastik.

Bei Unterkieferteilresektionen wegen benigner Tumoren und bei sicherer Radikalitat der Entfernung von Malignomen wird heute die sofortige Rekonstruktion resezierter Unterkieferanteile durch autologe Knochentransplantate angestrebt.

Tumorwachstum ist durch eine Störung des Gleichgewichts zwischen Zellproliferation und Apoptose charakterisiert. Sinn des ersten Teils dieser Untersuchungen war es, die Bedeutung von Proliferations- und Apoptose-assoziierten Faktoren in primären Plattenepithelkarzinomen der Mundhöhle und des Oropharynx bei 107 Patienten zu beurteilen. In neun Fällen wurden auch entsprechende Lymphknotenmetastasen untersucht. Für die Ermittlung der Apoptoseraten wurde eine durch terminale Transferase katalysierte enzymatische Markierung von DNA-Fragmenten verwendet. Die Parameter p53, p90MDM2, p21CIP, p16INK4a, Cyclin D1, pRB, BCL-2, BAX und das Proliferations-assoziierte Antigen Ki-67 wurden immunhistologisch bestimmt. Der Tumorsuppressor p53 war in den basalen Schichten des in den Tumorpräparaten miterfaßten Epithels abhängig vom Dysplasiegrad vermehrt nachweisbar (p, Tumour growth is characterized by an imbalance between cell proliferation and apoptosis. The aim of the first part of this study was to estimate the importance of proliferation- and apoptosis-associated factors in primary squamous cell carcinomas of the oral cavity and the oropharynx obtained from 107 patients. In nine cases also corresponding lymph node metastases were examined. DNA-fragments were marked enzymaticly catalysed by a terminal transferase reaction for the recognition of apoptosis. The parameters p53, p90MDM2, p21CIP, p16INK4a, cyclin D1, pRB, BCL-2, BAX, and the proliferation-associated antigen Ki-67 were determined immunohistochemically. The tumour suppressor p53 was mainly detectable in the basal cell layers of the epithelium included in the tumour specimens additionally depending on the grade of dysplasia (p