[Use of a fibula bone span in alveolar ridge augmentation. Outcome after 2 years]. / Verwendung des Fibulaspans bei der Kieferkammaugmentation. Ergebnisse nach 2 Jahren.

A preliminary report presenting the results of fibular strut grafting in the severely resorbed mandibular and maxillary region is presented. Thirteen patients were treated due to severe resorption of alveolar and basilar bone of 49 segments of the mandible and the maxilla. Two patients additionally had pathological fractures of the mandible. In 10 cases the strut graft was harvested by means of a new minimally invasive technique. After modelling the fibular bone it was fixed to the recipient site by miniscrews or implants. After a mean follow-up period of 20 months (max. 31, min. 11 months) a retrospective analysis of clinical and radiological findings was carried out. It showed that a mean augmentation of 16 mm was achieved. Compared to other studies the fibular strut graft was resorbed less, and due to the primary stability it could be used for the treatment of fractures of the mandible. No more than natural resorption was observed when the patients received their prostheses fixed to dental implants.

Free flap transfer and the prevention of endothelial damage.

Prolonged ischemia is thought to have detrimental effects on the most vulnerable structure of a free flap, the intima. We investigated experimentally and clinically the effects of ischemia on microvascular flaps, with emphasis on the endothelial cell lining and the efficacy of cold storage solutions in preventing endothelial damage. Experimentally, we investigated three cold storage solutions--the Eurocollins solution, Bretschneider's solution, and the University of Wisconsin solution-histologically, submicroscopically, and functionally regarding their ability to protect the intima. The University of Wisconsin solution proved superior to the Eurocollins and Bretschneider's solutions. Our preliminary results on the clinical free flaps confirm a relationship between the duration of ischemia and the secretion of prostacyclin. We therefore recommend that operating teams be organized to allow immediate reanastomosis following free flap elevation. If immediate reanastomosis is not possible, our results indicate that perfusion with the University of Wisconsin solution provides optimal endothelial protection and increases flap viability.

[3-dimensional reconstruction of the superficial facial contour using opto-electronic recording for control of reconstructive soft tissue interventions]. / Dreidimensionale Erfassung der oberflächlichen Gesichtskontur mit Hilfe optoelektronischer Abtastung für die Kontrolle weichteilverlagernder Eingriffe.

We present a method of scanning the facial surface optoelectronically by means of the coded light approach. Using 20 plaster models of patients who had undergone plastic surgery of the face, we investigated the indications and possible limitations of this registration method. Using a 3D scanner developed by Duwe, we found that this method is limited in posterior areas. Further hardware and software improvements will permit volumetric control. The advantages of this new technology lie in planning, follow-up and in improved patient instruction for plastic surgery.

[Life-threatening swelling of the tongue in antihypertensive therapy with ACE inhibitors]. / Lebensbedrohliche Zungenschwellung bei antihypertensiver Therapie mit ACE-Hemmern.

Although generally showing a low incidence of side effects, inhibitors of angiotensin-converting enzyme (ACE) may in rare cases induce angioedemas, mainly located in the oro-facial area and larynx. The interval between the beginning of the ACE inhibitor therapy and the occurrence of such angioedemas may range from a few hours to a few years. Here, the case of a 53-year-old man with massive swelling of the tongue after dental surgery is presented who had started with ACE inhibitor therapy only 24 h before. At admission to the clinic, obstruction of the upper airway due to the tongue swelling had already progressed so far that fiberoptic intubation was necessary. Additionally, the patient was treated with corticosteroids, antihistaminics and epinephrine, avoiding any further administration of the ACE inhibitor. The swelling resolved within 48-72 h. Dentists and physicians should take into consideration this potential side effect in patients treated with ACE inhibitors.

[Wound management after wisdom tooth osteotomy]. / Wundversorgung nach Weisheitszahnosteotomie.

Closure and dressing techniques in wound treatment after surgical removal of the mandibular third molars were compared. Large abscesses were found after third molar removal in 8 percent. An extraoral incision was made in 58 percent of these cases. On the other side, in a group of 1189 third molar removals treated by a gauze strip no abscess was observed. In a further investigation the subjective disturbance of patients treated with a dressed gauze were the slightest. Also, the dressing technique in the treatment after third molar removal could decrease the number of postoperative infections.

[The RTOG score (Radiation Therapy Oncology Group) as a guide to treatment of the irradiated field]. / Der RTOG-Score (Radiation Therapy Oncology Group) als Leitfaden zur Behandlung im vorbestrahlten Gebiet.

The RTOG score, which describes radiation-caused side effects in a reproducible way, was introduced as a guide for the treatment of irradiated patients. By means of a prospective study (27 patients; acute effects) and a retrospective study (81 patients; long-term effects) the score was evaluated. Special importance was placed on the recording of dental and maxillofacial findings as well as on the therapeutic outcome. It was shown that frequency of dental lesions increased with the score of radiation effects while dental treatment decreased inverse to the score of radiation effects. Evaluation of radiation reactions of the lower jaw showed better results concerning preventive treatment and osteoradionecrosis than have been described in the literature.

Experimental improvement of microvascular allografts with the new material polyurethane and microvessel endothelial cell seeding.

The major aim of this experimental study was the improvement of hemo- and biocompatibility of microvascular allografts. Comparison of polyurethane and ePTFE (expanded polytetrafluoroethene) micrografts did not show a significant advantage of the new material polyurethane. When the endothelial cell seeding method was applied, endothelial cell harvesting from rat fat proved to be very difficult. Therefore, further research on microvessel endothelial cell seeding is planned.

Fibrin sealing and histometrical changes in conventionally sutured microvascular anastomoses.

Reports from the literature demonstrated an early occlusive thrombosis rate of microvascular anastomoses of up to 25%. In order to reduce free flap failure due to kinking and pressure in the region of the anastomosis, fibrin sealing of microvascular anastomosis was recommended in previous studies. However, it is well accepted that haemostasis is activated by vascular wall injuries (lesions of the endothelial layer). For that reason, a fast re-endothelialisation of the inner surface of the anastomosis is thought to reduce early occlusive thrombosis and, subsequent, free flap failure. To clarify whether application of fibrin adhesives exert any effect on microvascular anastomoses, we constructed 84 anastomoses in rat arteries applying sealant or non-sealant in randomized order. At certain time intervals, arteries operated on were removed and histologically analyzed. Early complete endothelial regeneration, 4 days after surgery, was observed in the unsealed anastomosis group, whereas sealed anastomosis showed a complete re-endothelialisation only after 7 days. These observations may be explained by a reduced multiplication rate and migration speed (0.3 mm/day) of endothelial cells during the first 3 days (unsealed anastomosis: 0.63 mm/day). In addition, in sealed anastomoses a higher incidence of media necrosis was found (60.7% vs 49.3% in the unsealed group). These histological changes were confirmed by scanning and transmission electron microscopy.

Malignant lymphoma of the mucosa-associated lymphoid tissue (MALT)--consecutive unusual manifestation in the rectum and gingiva.

Non-Hodgkin's lymphomas (NHL) of the mucosa-associated lymphoid tissue (MALT) are characterized by a preferential mucosal manifestation. Each organ system may be involved. Exclusively local growth is usually treated with surgical tumour reduction, combined with radiotherapy. In cases of tumour dissemination, chemotherapy is warranted. Follow-up should be performed closely. This case report highlights an unexpected recurrence of NHL in the oral MALT, four years after primary manifestation in the rectum.

[Oral leukoplakias--a histopathological and retrospective study]. / Orale Leukoplakien--eine histopathologische und retrospektive Studie.

In a retrospective study 85 patients of our department with clinical oral leukoplakia occurring between 1980 and 1985 were checked histologically and reclassified. Compared to other studies and unusual high malignant transformation rate (14.1%) was found which seemed to be depended on the high rate of radiated patients. Four of twelve patients were healed due to early diagnosis and radical surgery performed consecutively. Using these data as a basis the different courses and therapies are demonstrated.

[Biocompatibility studies of periodontal dressings]. / Untersuchungen zur Biokompatibilität von Parodontalverbänden.

Periodontal packs have to be considered medications due to their direct contact to the gums and wound surfaces. For this reason a high cell biological compatibility has to be considered as one of their most important properties. For this reason, the cytotoxicity of all periodontal packs commonly used in Germany was examined, using the "Erlangen Ciliate Test". This method, which is commonly used to determine the cytotoxic and cytostatic properties of a wide variety of different materials and substances, is based on liquid cultures of the eucaryotic organism "Tetrahymena piriformis", using an excellent correlation with mammalian or human tissue cultures as well as the LD50. A significant toxicity of up to 50% could be shown in all but one periodontal pack. In addition, the antibacterial properties of the same materials were examined, using liquid cultures of Staphylococcus aureus and hemolyzing streptococci group A. However, using this method, no significant antibacterial effects could be shown.

[Radiological findings in therapy planning and follow-up control of fibrous dysplasia]. / Radiologische Befunde in Therapieplanung und Verlaufskontrolle der fibrösen Dysplasie.

25 patients with fibrous dysplasia have been treated surgically between 1980 and 1989. For monostotic manifestations which occurred mostly in the lower jaw, as well as for the follow up control, the conventional x-ray examination beneath anamnestic data was sufficient. Polyostotic extracranial lesions have mainly been diagnosed by scintigraphy. For exact statements about the extend and the involvement of functionally important structures, specially in the orbital and skull base region, CT proved to be the most effective diagnostic method by showing simultaneously bony and soft tissue structures. To our knowledge not yet described in the literature, we diagnosed a manifestation of several cervical vertebrae in one case.