International Poster Journal of Dentistry and Oral Medicine, 04/1999

Transfusion frequency rates were determined in a patient population of 229 having undergone major oral and maxillofacial surgery as follows: tumor surgery (TU, n=54), orthognathic surgery (OR, n=41), preprosthetic surgery (PR, n=7), reconstructive surgery (RE, n=49) and traumatology (TR, n=78). Duration of surgery was in the range 2 - 20 hours. Autohaemotherapy was of particular significance for orthognathic operations. Statistical evaluation was via variance analysis and the chi-squared test (significance level alpha=0,05). The resulting transfusion frequency rates were as follows: TU 55.6%, OR 31.7%, PR 14.3%, RE 12.2% and TR 5.1%. Transfusions were significantly more often needed in the following operations: TU>OR/RE/TR and OR>TR. The number of transfusions was found to increase as operation time increased (0- 2h: 0%, 2- 4h: 1,5%, 4-6h: 12,9%, 6-8h: 34,5%, 8-10h: 60% and 10h: 100%). The value for 10h was statistically significantly greater than the values for the remaining operation times. The following laboratory values for the non-transfused patients were statistically significantly different compared to those receiving transfusions (shown in brackets): haemoglobin preoperative 141 (129) g/l, haemoglobin postoperative 122 (111) g/l, serum calcium 2.49 (2.38) mmol/l and leucocytes 9.23 (7.98) G/l. 96.8% of all autohaemotherapy applied to the orthognathic patients. Retransfusion was carried out in 35.5% of the cases. Heterotransfusion of blood is to be decided at a probability greater than 5%. This can be assumed in oral and maxillofacial surgery in the subdisciplines tumor, orthognathic and reconstructive surgery, as well as operations taking 4-6 hours and longer. Autohaemotherapy provides an alternative. A further outcome of the investigation was that low haemoglobin, serum calcium and leucocyte values more often resulted in transfusions. Palabras clave: transfusion frequency rates, oral and maxillofacial surgery

Problem: Installation of fixtures for prosthetic reconstruction in the upper jaw in patients with extensive bone and soft tissue defects is still a challenge. These situations normally require the support of vascularized bone or composit grafts and secondary insertion of endosseous implants. Aims: The new fixture developed by Brånemark System achieves instant prosthetic reconstruction by anchoraging implants in the zygomatic bone to offer sufficient support even in the above described situations. The dimension of these zygomaticus fixtures and the complex anatomy due to previous surgical procedures demand specific treatment for a precise and safe insertion of the implants. Method: On the base of an axial spiral CT data set the STN-3.5 navigation system (Leibinger/Zeiss) was used for preoperative planning and intraoperative controlling of insertion of zygomaticus fixtures after subtotal maxillectomy. Bilateral insertion of zygomaticus fixtures was done substituting standard Brånemark fixtures placed in the remaining anterior maxillary bone after resection of the posterior maxilla because of a squamous cell carcinoma. Results: Computer assisted insertion of zygomatic fixtures was successfully completed. The implants could be positioned precisely as preoperatively planned. Conclusions: The use of zygomatic fixtures after ablative tumor surgery with resection of the maxillary bone provides immediate prosthetic reconstruction without additional bone grafting. Computer assisted insertion of these implants improves preoperative planning by valid 3D visualization of the anatomic situs and virtually positioning of the fixture and faciliates clinical procedure by guiding the drill to the intended position. Palabras clave: Rahmenlose Stereotaxie, computergestützte Chirurgie, Zygomaticus Fixture, Tumorchirurgie

In a prospective randomised study in hospitalised patients in the year 1973 and 1998 microbial findings in odontogenic abscesses and wound infections were recorded. In severe odontogenic abscesses the profile of bacteria changed: the "typical" Gram positive pathogens, which predominantly identified in 1973 were less frequently observed in the recent study episode. In contrast, the number of Gram negative bacteria appears to be increased in 1998. Additionally, the number of culture negative episodes in severe odontogenic abscesses seems to be increased. In the group of patients with post operative wound infections the number of Gram negative bacteria remains unchanged, accounting for >50% of the culture positive episodes. In the data from 1998, a high incidence of anaerobes is found in both groups of patients, emphasising the need for routine testing of these pathogens. Yeasts identified in both patient groups seem to have increased but their pathogenic role has to be further elucidated. Palabras clave: Rahmenlose Stereotaxie, computergestützte Chirurgie, Zygomaticus Fixture, Tumorchirurgie

AimS: Temporomandibular joint (TMJ) ankylosis in early childhood results in a typical pattern of mandibular and midfacial growth deficiencies. In adult patients the interdisciplinary team approach includes an operative release of the ankylosis, orthodontic alignment of the dental arches, reconstruction ot the TMJ and adjustment of the occlusal plane by complementary maxillary and/or mandibular osteotomies. MaterialS AND Methods: due to late onset of initial treatment in four patients with severe deformities as a consequence of long lasting joint malfunction, surgical reconstruction had to be delayed until adulthood. In three of them unilateral TMJ ankylosis occurred following condylar fractures in the second or third year of life. After release of the ankylosis by resection of the osseous bridge and temporary interpositioning of a silastic sheet, reconstruction of the TMJ with a costochondral graft was performed in a two-stage operation, together with complementary osteomtomies to reposition the tilted occlusal plane. Intermaxillary wire fixation was employed for approximately 2 weeks. Results: The en face aspects, as well as profiles, were markedly improved in all patients. Stable occlusion and acceptable facial symmetry was achieved in 3 out of 4 patients. All patients suffered temporary palsy of the facial nerve that recovered within 3 to 4 month. Pre-operative alignment of dental arches could not be achieved in one patient with considerable myofunctional habits, resulting in an increase of funtional loading of the reconstructed TMJ. In this particular case resorption, secondary infection and finally loss of the costochondral graft was witnessed. Conclusion: TMJ reconstruction, with predictable results, can be achieved in adult patients by costochondral grafting and simultaneous surgical correction of the concomitant dentofacial deformities. A careful dental alignment pre-operatively is mandatory, not only for long-term occlusal stability but also to prevent functional overloading of the graft post-operatively. Palabras clave: Rahmenlose Stereotaxie, computergestützte Chirurgie, Zygomaticus Fixture, Tumorchirurgie