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Seventeen mostly elderly patients, 13 men and 4 women, were consecutively admitted for implant-prosthodontic treatment after they had undergone resection of malignant tumors in the oral cavity. A total of 53 dental implants (ITI-Straumann) was placed, 12 in the maxilla, 41 in the mandible. The prosthetic rehabilitation consisted of overdenture therapy in 15 patients, and 2 patients were treated with fixed partial prostheses. Thirty-three implants were prescribed for patients who received radiotherapy either before or after implant placement. The average dose varied between 50 and 74 Gy. Eighteen implants were located in grafted bone from the fibula, scapula, or hip. For 2 patients, hyperbaric oxygen therapy was also prescribed after osteoradionecrosis had developed. One implant was lost before prosthetic loading. During an observation period of up to 7 years after loading, 3 more implants were removed. All implant losses occurred in the mandibles of patients who had received radiotherapy. A life table analysis was performed, and the cumulative survival rates, calculated for 2, 3, and 5 years, were 93%, 90%, and 90% respectively. No failures or complications were observed with technical components of the implants or prostheses. All prostheses could be maintained during the entire observation time. Although in the present investigation the survival rate of implants was slightly lower than under standard conditions, the treatment with implant-supported prostheses seemed to be advantageous for patients who had undergone intraoral resections.

This paper describes the application of a new material, Biocem, for retrograde root canal filling. A total of 234 roots in 222 teeth were treated during the period 1987-1992. Biocem consists of two components and once mixed, the autopolymerisation results in a three-dimensional structure. The biomechanical and histologic properties and a clinical longterm follow-up confirm the optimal qualities of this material. It fulfills the requirements in regard to biocompatibility, watertight sealing and application. The material proved superior in comparison to conventional materials and ceramics. The evaluation of the results are most encouraging.

Van der Woude syndrome (VWS) is an autosomal dominant disorder associated with one or more of the following features: clefting of the primary or secondary palate, hypodontia or lower lip pits. It has been estimated to account for 2% of all cases of cleft lip and palate. VWS is one of the rare disorders in which clefting of the primary and secondary palate may be seen to segregate as components associated with the same gene. Because of its autosomal dominant inheritance, VWS is readily accessable to linkage analysis as a preliminary step in the identification of the molecular abnormality underlying the clefting effect in the primary and secondary palate. A reported linkage between REN and VWS has promoted us to use pHRnX3.6 (REN) and several markers surrounding REN for a linkage analysis in a large Swiss family. In a second step, linkage analysis was performed to study restriction fragment length polymorphisms for the candidate gene TGFB2 and other loci recently mapped to the candidate region 1q32-1q41. Evidence for linkage (theta = 0.00, lod score = 3.01) between REN and VWS could be confirmed in this pedigree. TGFB2 demonstrated recombination with the disease locus and is unlikely to be causative in VWS. The results of a multipoint linkage analysis showed that VWS was flanked by D1S65 and TGFB2 at a maximum location score of 20.3.

The THORP system is designed for bridging mandibular defects and for internal osteosynthesis of mandibular fractures. The major aspects and advantages of the THORP system compared with the conventional reconstruction plates and screws are: 1. The rigid fixation of the head of the screw to the plate, thus avoiding unphysiological loads to the bone underneath the plate. 2. The titanium-plasma coated and perforated hollow screws enable the development of direct bone-titanium contact at the area of the thread as well as the ingrowth of bone into the lumen and perforations. Further advantages are the preservation of small fragments such as the condylar process with only two screws and the stable fixation of bone transplants. The specially designed freely adjustable condylar prosthesis guarantees a correct guidance and function of the lower jaw. The fixation of this system to the lingual aspect of the jaw is particularly significant avoiding decubitus and perforation of the skin in the chin area. The results and the complications of 141 reconstructions of the lower jaw are discussed.

The biomechanical and design principles of the titanium hollow screw and reconstruction plate (THRP) system are described. Physiologically advantageous load transmission, a biocompatible implant material with sufficient strength and a surface structure favorable to biological stabilization are discussed. The design of the fixation between the cross-split screwhead and the plate hole gives a rigid and stable plate fixation even without contact between plate underside and bone. Blood perfusion and bone strength will therefore not be affected. Full functional loading with only 2–3 fixation screws for each plate end is possible. Further technical advantages of the THRP system are the possibility of lingual plate application and integration of a three-dimensional adjustable condylar prothesis.

The animal experimental methods as well as the clinical application in patients and histological results of a new reconstruction plate for use in bridging defects in the lower jaw are discussed. The principles of fixation of the plate with hollow titanium powder sprayed screws and a titanium mesh for stabilising the autologous cancellous bone are also given. Resection was carried out in irradiated and non-irradiated mandibles of dogs. The direct contact between the surface of the screw and the bone as well as proliferation of bone into the hollow screw are demonstrated by light and scanning electron microscope studies. New methods for the evaluation of the interface between implant and bone are described.

Bacterial allergy causing perennial rhinitis remains a controversial nosological entity. Clinically, however, many cases of perennial rhinopathy do fit into the definition of this disease, and may represent a late stage of earlier inhalant allergy. It is characterized by positive delayed (type IV) skin tests with bacterial extracts as well as by a pronounced tendency to oedema and polyp formation. Topically applied steroids seem to provide sufficient prophylactic protection. Acute bacterial infections or any nasal surgery, however, require antibiotic treatment.

This publication concerns two cement forming tumours - the centrally cementifying fibroma and the true cementoma. The centrally cementifying fibroma is a rare tumour and has been considered an entity for some time. Our case presents a lesion of a size and a homogeneous histological structure rarely encountered. The operative procedure is also discussed. The progression from the radiolucent to the radio-opaque stage could be observed radiologically in the case of a cementoma.

Trauma is the major cause for temporomandibular joint (TMJ) ankylosis. 20 patients with posttraumatic TMJ ankylosis were surgically treated with interposition of lyophilized homologous cartilage between the newly-formed condylar head and the articular fossa. The follow-up of all patients revealed a correct function of the TMJ. A meticulously performed surgical exposure is decisive for the prevention of facial nerve paresis.

Experience in the management of 916 fractures of the mandible stimulated us to develop new methods and surgical techniques for functionally-stable intraoral internal plate osteosynthesis. The development of a fixation bar which is adapted to the alveolar process of the fractured mandible enables a compression of this area prior to the plate osteosynthesis. This procedure facilitates the plate application from the intraoral approach so that in 358 cases all types of fractures of the body, angle and ascending ramus can be reduced using this access, and not only the selected favourable cases. A new plate and screws of our own design have been successfully used in cases with comminuted multifragmentary and defect fractures. The rigid fixation of the head of the screws to the plate produces an optimal functional stability compared with conventional systems. The combination of the advantages of an external fixation device and those of stable internal osteosynthesis produces a long term functional stability even in cases with extensive defects where delayed consolidation is to be expected; tilting and loosening of the screws or resorption of the compact bone underneath the plate do not occur. Thus the extraoral approach and visible skin incisions can be avoided. This procedure is time sparing and less traumatic to the soft tissues compared with the extraoral approach. The extremely low complication rate in 358 fractures managed by plate osteosynthesis using the intraoral approach confirms the efficiency of this method.

The aim of this paper is to emphasize the advantages of a one-stage, step by step repair of facial skeletal injuries as well as the dural tears and lesions of the anterior fossa, by one and the same team. The methods described permit optimal reduction of the pseudohypertelorism and major displacements in severe combined craniofacial injuries. The simultaneous subcranial exposure of the entire basal region of the anterior fossa obviates the intracranial approach or frontal lobe retraction thus making early stage surgical management feasible. The surgical treatment of these injuries as a single entity, as well as further modifications reduce complications such as recurrent CSF leakage, anosmia, mucocoele or secondary operations for inadequate fracture reduction. The significance of primary meticulous reconstruction of the combined cranial vault and midface fractures for the achievement of normal physiological function of the various systems is particularly highlighted.

A newly developed material, which we call biocement, consisting of bisphenol-a-glycidyl methacrylate ("epoxide methacrylate') as organic matrix and Bioceramic Battelle, Bioglass Hench and/or pentacalcium hydroxide triphosphate ("tri-calcium phosphate') powder as filling particles is presented. In an extension of previous experiments, various types of this biocement, containing different admixtures of particulate matter, were employed to test their usefulness in head surgery, in particular maxillo-facial reconstruction, on dogs and a rhesus monkey. Encouraging results were obtained with regard to (a) fixing a titanium alloimplant under some degree of mechanical stress; (b) covering a defect in the skull cap, including the closure of an artificially induced meningeal fistula with liquorrhea; and (c) reconstruction of defects in the anterior wall of frontal sinuses. Special emphasis is placed on direct contact between biocement and bone, interdigitations between these two, reactions of meningeal tissue, and regeneration of ciliated epithelium underneath fixed reimplants over the frontal sinus.

In the treatment of severe "dish-face" deformities which result from Le Fort II and III middle face fractures, reposition and fixation of the maxilla can be achieved by an extraoral cranial fixation apparatus. We describe a modification of the Georgiade head frame which achieves higher stability in fixing the maxilla and arch wires. The joints applied to the rigid wire connecting the arch bar to the head frame make an adaptation to the upper lip possible; traction of the maxilla to maintain its fixation can be applied extra-orally so that closure of the lips with correction of occlusion is possible, making easier the uptake of nourishment.

The results of treating mandibular fractures with rigid internal fixation are discussed. This method was used in 55 patients through the application of dynamic compression plates. The technique was then assessed critically and the followup treatment evaluated. Indications and contraindications for the procedure are discussed, as are possible errors or complications. In addition, selected cases illustrating the advantages of the procedure for reconstruction and functional rehabilitation of mandibular defects following ablative surgery or trauma are described.

The advantages and special features of the THRP-system enabled us to develop new operative techniques. The combination of the advantages of external fixation devices and those of the internal osteosynthesis has proved to be decisive in order to obtain good results. The clinical results in 30 patients confirm the recently published findings from animal studies. Histological examination of human specimens comparing 2 types of screws developed by us are discussed.

The various surgical techniques for the repair of mandibular defects following ablative surgery are discussed. The methods used in the treatment of large mandibular cysts are described and a modification of the osteoplastic technique is presented. The importance of reconstruction and functional rehabilitation with so caused mandibular defects and temporo-mandibular joint substitutions are stressed.

In this paper the surgical management of TMJ dysfunction-ankylosis and arthropathies-is described. The surgical techniques and the necessity of wide exposure are pointed out. Only thus are correct reshaping of the condyle, repair of the disc and radical resection of ankylotic bone tissue possible. The indication for prosthetic substitution to be interpositioned in cases with discal atrophy and perforation is discussed. There were no cases of facial paresis and no recurrence of ankylosis. The results, in regard to the functional aspects, confirm the efficiency of the methods described.

Twenty-nine patients with 249 fractures of the condylar process were treated by surgery which was reserved for fractures with medial dislocation of the condylar head out of the articular fossa. The fractures were exposed from a preauricular incision. Interosseous wires were not used: intermaxillary fixation for 10 days and functional treatment for another 3 weeks were the standard post-operative treatment. The operative technique and the results are described.

The various advantages rendered by the system described enable primary as well as long-term functional stability even in cases in which conventional systems would be insufficient. The evaluation of 49 cases managed in Bern and Sweden confirm the efficiency of this reconstruction system.

In this paper we describe the various surgical techniques in the treatment of cysts of the mandible and maxilla. The importance of primary reconstruction of extensive defects is pointed out. We developed a special press for autologous cancellous bone to achieve better osteoplastic results. We describe the advantages of this technique in comparison to the conventional methods.

This paper deals with the management of 269 patients with frontobasal fractures of which 143 were treated operatively. The close interrelation between midface and base of skull and our operative modifications are discussed. The advantages and importance of the transethmoidal approach to the base of the skull is most adventageous for reconstruction of the midface pillars. Specially for comminuted fractures, avoiding complications such as pseudohypertelorism, telecanthus and frontobasal disturbances. This also enables an accurate reposition to be made with minimal use of foreign materials such as wire ligatures and miniplates. The operation should be performed by the same surgeon in a single sitting thus combining the transethmoidal approach with the midface reconstruction. The reduction of the rate of CSF recurrent leaking to only 3,5% is ascribed to these methods.