Biomedical subjects

H Eufinger

Publications and source records attributed to H Eufinger.

At least 37 records · Page 2Linked to original sources

PubMed2001

Computer-assisted prefabrication of individual craniofacial implants.

Historically, reconstruction of the skull with intraoperatively modeled implants has been restricted severely by limitations in implant material, unpredictable aesthetic results, prolonged OR time, and indirect techniques that cause decreased precision and increased expense. This article discusses modern computer-aided design and manufacturing systems that allow for direct preoperative fabrication of implants out of pure titanium with a variety of enhanced construction details. Between 1997 and 1999, 135 cranial and craniofacial reconstructions with defects measuring up to 22 cm were performed using this technique at 25 health care centers in Europe. The results obtained in these patients were predictable and constant and demonstrated dramatically reduced OR times.

Adult↗

PubMed2001

Purulent pansinusitis, orbital cellulitis and rhinogenic intracranial complications.

Objectives: Acute pansinusitis is rarely seen in the maxillofacial surgery field, but often occurs in combination with orbital and intracranial involvement. Clinically this entity is of great importance, since it represents a severe disease with possibly disastrous consequences. Patients: Aetiology, diagnosis and therapy of acute pansinusitis and its complications were analysed in 36 patients treated surgically from 1987 to 1996. Results: Eighteen patients were aged between 3 and 21-years-old. Only eight suffered from pure pansinusitis, and three of an isolated purulent orbital infection. Of these 25 patients 20 had (pan-)sinusitis with orbital, three with intracranial, and two with both orbital and intracranial complications. Intracranial involvement included meningitis, empyema and brain abscess. Aetiology was rhinogenic in 26, odontogenic in six patients, and traumatic in two cases. Radiological work-up included conventional radiographs and CT in most cases, MRI was only used with special indications. Microbiological examination detected single or multiple species of micro-organisms with equal frequency. If multiple species were found, infection was mostly aerobic/anaerobic in combination. Conclusion: These purulent processes, frequently seen in young patients, require immediate surgical intervention and drainage with elimination of the cause of the disease if possible. Cooperation with other specialities is essential depending on the spread of the disease. In spite of the threatening acute symptoms, severe courses of disease or permanent defects should be avoidable. Copyright 2001 European Association for Cranio-Maxillofacial Surgery.

Journal Article↗

PubMed2000

[Pure titanium as bone substitute. Geometric and substance-specific aspects of computer-assisted fabrication and follow-up imaging].

Computer-assisted prefabricated skull implants of pure titanium as a bone replacement material have been used in 22 departments since 1994. Our experience with 104 implants includes clinical aspects (indication; tissue quality; surgical technique; patient guidance), but also geometric and material-specific parameters (acquisition, transfer, and evaluation of CT data; construction; manufacturing; cleaning; postoperative use of radiologic techniques). While the clinical aspects are responsibly defined by the respective surgeon, the geometric and material-specific parameters of individual implants have to comply with the laws on medical products. Therefore, the prospective documentation for each implant includes: helical CT acquisition parameters; geometric data of the computer-based skull model and implant; the cleaning procedure; and the individual marking. Medically specified pure titanium is processed by milling only so that neither purity nor structure is impaired. A specially developed milling technique guarantees the fabrication of all constructed elements down to fine details of 50 microns. Considering the necessary radiologic follow-up of defects after tumor surgery, all patients in our hospital undergo postoperative MRI examination, partly with preoperative documentation as an intraindividual control. Such comprehensive documentation and quality assurance is essential for techniques of prefabricated bone substitution. Hand in hand with scientific research and clinical application, these formal criteria have to be elaborated and fulfilled for the respective techniques. The successful determination of specifically adapted MRI sequences goes even one step further: spin-echo sequences minimize inhomogeneities of the magnetic field induced by the titanium implants and enable accurate postoperative documentation and diagnostics especially in the follow-up after tumor surgery.

Bone Substitutes↗

PubMed2000

[Mandibular involvement in chronic recurrent multifocal osteomyelitis (CRMO) in adulthood].

A 42-year-old patient was admitted to our clinic with the diagnosis of primary chronic osteomyelitis of the mandible. Since the initial manifestation, approximately 9 months earlier, the patient had undergone numerous antibiotic treatment trials. Various tissue specimens exhibited no microbial growth. Computer tomography demonstrated severe sclerotic changes with partly osteolytic areas in the complete right horizontal ramus of the mandible. Decortication was carried out and both soft and hard tissue specimens were taken. Histological assessment revealed slightly sclerotic bone with reactive periosteal bone production, as in chronic non-specific osteomyelitis. Because of progressive pain and paresthesia, a 3-phase skeletal scanning was performed before the planned resection. In addition to an intensive labeling in the right mandible, further intensive lesions were found at the first right rib, the sternum, and the vertebral column. The subsequent magnetic resonance tomography confirmed the infiltration, as seen in osteomyelitis, in all these areas. Under the assumption of chronic recurrent multifocal osteomyelitis (CRMO), an immunosuppressive therapy with diclofenac and prednisolone was started, which at first brought about complete remission. As CRMO is very rare in our specialty, it might be suspected that it is the cause of some cases of primary therapy-resistant osteomyelitis. The importance of early diagnosis must be underlined, because therapy differs fundamentally from that of the more common bacterial osteomyelitis. A bone scan is therefore of great value in the diagnostic scheme of therapy-resistant osteomyelitis.

Adult↗

PubMed2000

Iliac crest donor site morbidity following open and closed methods of bone harvest for alveolar cleft osteoplasty.

Donor site morbidity after bone harvesting still remains a crucial problem in alveolar cleft osteoplasty. This study focuses on ilium donor site morbidity comparing two different techniques. A series of 52 consecutive patients was divided in half. All had anterior iliac crest bone grafts. In the study group the harvesting was performed with a closed osteotomy using a cylindrical Shepard osteotome. The control group underwent the traditional open osteotomy. In the open osteotomy group the short-term morbidity at the donor site was slightly greater than in the closed harvesting group. The low short-term morbidity in the closed harvesting group was reflected in the analgesic consumption which was three times higher in the open osteotomy group (p < 0.008). The most striking difference occurred in the appearance of the mature scar: a length of 24.2 mm (mean) in the closed harvesting group against 60.3 mm in the open osteotomy group (p < 0.0001), and a width of 4.9 mm (mean) versus 7.7 mm, respectively (p < 0.003). The long-term morbidity was negligible in both groups. Based on these findings we suggest that bone harvesting from the anterior iliac crest remains the preferred method, provided that closed harvesting is undertaken.

Adolescent↗

PubMed2000

[Management of simple midfacial fractures, particularly in professional soccer players].

Uncomplicated midfacial fractures represent a frequent and typical injury of soccer-players in oral and maxillofacial surgery. The treatment of these fractures in professional players requires special treatment modalities, especially concerning quick rehabilitation. The examples of a nasal bone fracture, a malar bone fracture and a zygomatic arch fracture in 3 professional soccer players demonstrate the therapeutic principles of these most common uncomplicated midfacial fractures. In this context the fabrication of individual facial masks is presented, which allow an improved postoperative protection and therefore an earlier participation of the player in training and matches.

Adult↗

PubMed2000

Neoadjuvant, hyperfractionated irradiation induces apoptosis and decreases proliferation in squamous cell cancer of the oral cavity.

Twenty-eight patients with squamous cell carcinoma of the oral cavity were treated with a total dose of 20 Gy. Tissue samples for immunohistochemistry were taken at the time of diagnostic biopsy and at surgery after radiotherapy (RX). For detection of proliferating cells, the immunoperoxidase reaction with Ki67 was performed. Apoptotic cells were detected by the TdT-mediated biotin dUTP nick end labeling (TUNEL) method. RX reduced proliferation in 27 patients, only in one case did the proliferation index (PI) increase. Delta PI (PI before RX PI following RX) amounted to 4.11% (SD=3.2%; P<0.0001). The apoptotic index (AI) increased significantly subsequent to neoadjuvant RX. Delta AI (AI after RX--AI before RX) measured 1.82% (SD=0.9; P<0.001). These data indicate that RX of patients suffering from squamous cell carcinoma of the oral cavity with a dosis of 20 Gy induces apoptosis and inhibits proliferation of tumor cells.

Adult↗

PubMed2000

Synthesis of CAD/CAM, robotics and biomaterial implant fabrication: single-step reconstruction in computer-aided frontotemporal bone resection.

The preoperative manufacturing of individual skull implants, developed by an interdisciplinary research group at Ruhr-University Bochum, is based on the use of titanium as the most common material for implants at present. Using the existing technology for materials that can be milled or moulded, customized implants may be manufactured as well. The goal of the study was to examine biodegradable materials and to evaluate the practicability of intraoperative instrument navigation and robotics. Data acquisition of an adult sheep's head was performed with helical computer tomography (CT). The data were transferred onto a computer aided design/computer aided manufacturing system (CAD/CAM system), and two complex defects in the frontotemporal skull were designed. Standard individual titanium implants were milled for both of the defects. Additionally, for one of the defects a resection template, as well as a mould for the biodegradable poly(D,L-lactide) (PDLLA) implant, were fabricated by the CAD/CAM system. A surgeon carried out the first bone resection (#1) for the prefabricated titanium implant using the resection template and an oscillating saw. The robot system Stäubli RX90CR, modified for clinical use, carried out the other resection (#2). Both titanium implants and the PDLLA implant were inserted in their respective defects to compare the precision of their fit. A critical comparison of both implant materials and both resection types shows that fabrication of a PDLLA implant and robot resection are already possible. At present, the titanium implant and resection using a template are more convincing due to the higher precision and practicability.

Absorbable Implants↗

PubMed1999

[Significance of the height and width of the alveolar ridge in implantology in the edentulous maxilla. Analysis of 95 cadaver jaws and 24 consecutive patients].

Consideration of alveolar profiles and clinical experience demonstrate that the transversal dimension has been neglected in dental implantology so far. For a comprehensive evaluation of the impact of alveolar bone height and width, 95 edentulous bony maxillae with standardized, measured, and classified cross-sections were analyzed. With four types of implants (minimum length, 10 mm), 1076 insertions were simulated at 269 cross-sections and evaluated with regard to type of implant, position of cross-section, and class of atrophy. Similar evaluation was carried out in the clinical part of the study on 24 consecutive patients with edentulous maxillae. Implant insertion could only be simulated in 35% of the cadaver cross-sections, but had been expected in an additional 4.5% based on their sufficient bone height; length reductions were necessary in another 6%. These results depended largely on the class of atrophy. Anterior cross-sections offered better conditions than posterior ones. In contrast, implant insertion was impossible in all 24 patients. Height was primarily inadequate in 22 patients, and in two patients with sufficient bone height inadequate transversal dimensions were only recognised intraoperatively. These results allow a quantification of the impact of vertical and transversal maxillary alveolar bone dimensions. This impact primarily depends on bone height, but even with sufficient height, reductions of implant length often become necessary. Both for the cadaver maxillae (12% of the cross-sections with expected implant insertion) and for the patients (8%), alveolar profiles remain in which height measurement alone leads to incorrect assessment and may even result in the interruption of precisely planned surgical procedures. The complexity and expense of implant-borne rehabilitation and the consequences resulting from incorrect preoperative planning therefore generally justify extended cross-sectional diagnostic measuring.

Alveolar Process↗

PubMed1999

One-step resection and reconstruction of the mandible using computer-aided techniques--experimental and clinical results.

In patients with advanced oral cancer, a resection of the mandible continuity is often indicated. This new method presented here uses computer-aided design and manufacturing (CAD/CAM) for preoperative fabrication of individual mandibular prostheses and their corresponding resection templates in a direct fashion without the need for additional physical models. In this experimental application, a segment of a dried mandible was resected and replaced by a titanium prosthesis prefabricated by CAD/CAM. It was the aim of this investigation to verify the processing chain and its precision, i.e., the fit of an individual implant, such as this. Although this new technique offers fascinating opportunities, possible clinical drawbacks have to be taken into account.

Bone Screws↗

PubMed1999

[Follow-up studies of 3-dimensional osteoplastic reconstruction of the extremely atrophied maxilla combined with implants].

In the severely resorbed maxilla, a 10-year success rate of only 49-74% of implants in combination with autogenous bone grafts has been reported. We developed a modified technique of antral inlay grafting and lateral and vertical onlay grafting of the severely resorbed maxilla for inserting implants to retain dentures. The clinical and radiologic results are presented. In 21 patients with severely resorbed edentulous maxillae, a total of 20 bilateral and one unilateral antral inlay graftings and lateral and vertical onlay graftings were performed after a prosthodontic setup. We opened the maxillary sinus by removing a bony window from the anterolateral wall and, after elevation of the sinus lining, grafted the sinus floor with corticocancellous iliac crest bone grafts. The maxilla was also augmented in the lateral and vertical direction. The bone grafts were fixed by osteosynthesis. After a median of 5 months, a total of 134 implants (Brånemark) were placed and later loaded by prosthodontic rehabilitation. Computed tomography (CT) scans were taken before the grafting procedure, immediately after grafting, after 4 months, and every year thereafter. A total of 94.8% of the implants were successful at the time of the abutment operation. After loading, two additional failures were seen in an average follow-up period of 2.5 years. Most patients were provided with implant-borne dentures. CT scans showed an average initial gain of vertical bone height of 3.7-17.7 mm. One year after grafting, a loss of 1.3 mm or 7% occurred. In the following 2 years, no major atrophy was observed. Statistical analysis showed no correlation between sex, bone height before augmentation, augmented bone height, and resorption of the grafted bone. We observed undisturbed healing and obtained large vertical bone heights, a high success rate, minimal resorption, and fully satisfactory prosthodontic rehabilitation; we can thus recommend our modified technique of reconstruction of the severely resorbed maxilla for routine use.

Alveolar Bone Loss↗

PubMed1999

[Amyloidosis of the tongue as a possible diagnostic manifestation of plasmacytoma].

Plasmocytic non-Hodgkin's lymphoma is the most common tumor of bone and bone marrow, typically diagnosed by symptoms such as monoclonal paraproteinemia, proteinuria, anemia and hypercalcemia. In its progress, deposits of amyloids in almost all organs can be observed. However, plasmacytomas which are diagnosed by macroglossia of primarily unknown etiology are rare. This case report presents a 61-year-old woman who suffered from a persistent swelling of the tongue with painful ulcerations. A biopsy led to the diagnosis of primary systemic amyloidosis of the light-chain type, which subsequently proved to be a plasmacytoma with lambda light-chains stage II after Durie and Salmon. In the course of the disease the patient developed further deposits of amyloids in the whole gastro-enteric system. Macroglossia as a primary manifestation of plasmacytoma is rarely described in medical literature. However, reports on deposits of amyloid in the tongue in advanced stages of disease are well known.

Amyloidosis↗

PubMed1999

[Tracheobronchial perforations--a complication after mouth, maxillary and facial surgery].

After difficult endotracheal intubation in oral and maxillofacial surgery, esophageal or tracheal injuries can cause mediastinal, pericardial or cervicofacial soft tissue emphysema. If a patient has of thoracic pain after general anesthesia, mediastinal emphysema should be taken into consideration because of the possibility of subsequent life-threatening complications. Diagnosis can be established with computed tomography and fiber-endoscopy. We present the diagnostic and therapeutic management of two patients.

Adult↗

PubMed1999

Experimental computer-assisted alloplastic sandwich augmentation of the atrophic mandible.

PURPOSE: This study evaluated the effectiveness of a technique that combined computer-aided surgery with alloplastic augmentation and implant-borne prosthodontic rehabilitation of the atrophic mandible. MATERIALS AND METHODS: Computed tomographic (CT) data from an atrophic cadaver mandible were transferred to a computer-aided design (CAD) system that prepared an anterior sandwich osteotomy. The cranial segment was moved upward and backward to provide an ideal alveolar relationship, and the geometry of the intermediate space was used to design a titanium implant. Furthermore, a surgical template was derived for the osteotomies, and insertion of dental implants was planned to stabilize both the transposed bone and the intermediate implant on the bony base. An identical implant for augmentation was also fabricated from poly-D,L-lactide in a mold as a possible resorbable carrier for osteoinductive proteins. RESULTS: The experimental surgery was successfully performed with maximum precision on the dried mandible. The fabrication of an implant made out of poly-D,L-lactide for the same purpose was also possible. CONCLUSIONS: This preliminary experiment showed that it is possible to use CAD/computer-aided manufacturing (CAM) technology to prepare a prefabricated template and a corresponding titanium implant for mandibular augmentation with a high degree of exactness. Dental implants could be planned and integrated in this procedure as well. The fabrication of a mold using this method also provided the opportunity to give a complex shape to possible carriers of osteoinductive substances.

Alveolar Bone Loss↗

PubMed1999

Reconstruction of an extreme frontal and frontobasal defect by microvascular tissue transfer and a prefabricated titanium implant.

A 30-year-old man was referred to us with an extreme frontal and frontobasal defect from a motorbike accident 12 years before. Multiple attempts at frontal and frontobasal revision and reconstruction had been performed over the years, with several episodes of meningitis. Reconstruction was planned in two steps. First, a revision of the anterior skull base with mobilization of meningeal adhesions and duraplasty, removal of infected masses of polymethylmethacrylate out of the upper ethmoid sinuses, and coverage with a deepithelialized latissimus dorsi free flap were performed. In the second step 3 months later, aesthetic forehead reconstruction was achieved with a pre-fabricated individual titanium implant. The predictable result of this two-step reconstruction was very pleasing. Safe separation of the cranial cavity from the upper airways was essential, requiring free tissue transfer in this case, and is a prerequisite for any alloplastic forehead reconstruction. Timing of the two-step procedure, including the CT data acquisition; handling of soft tissues, bone, and foreign material; and construction details of the implant demonstrate the necessary complex management of this, the most difficult case of the 88 applications of the new computer aided design and manufacturing technique thus far. Even the most elaborate computer aided preparation cannot be successful without consideration of established surgical principles.

Adult↗

PubMed1998

[Interdisciplinary diagnosis and therapy of traumatic optic nerve damage].

Traumatic optic nerve lesions (TONL) still pose a large clinical problem concerning early detection and treatment. Neuro-ophthalmology provides reliable tests to detect afferent lesions but these methods are limited to just 30% of the severely injured patients. Especially in the patient with multiple injuries, optic nerve injuries are hardly predictable. In the latter group we established well-known neurophysiological methods for early detection of afferent disorders of the visual pathway, i.e. flash-VEP ERG. Apart from these diagnostic problems of TONL, controversy still surrounds the appropriate treatment of TONL--whether conservative or surgical or even combined treatment should be advocated. Our aim was to establish a reliable diagnostic schedule, based on the combination of neuro-ophthalmological, spiral-CT and clinical findings, and a treatment plan, so that in any patient there is a distinct guideline as to whether there is a need for early treatment of the peripheral visual pathway or not. In 52 patients who were assessed by the above-mentioned schedule, we could detect any of the 20 afferent disorders of the peripheral visual pathway. Although it is difficult to prove therapeutic effects on the injured optic nerve, immediate combined conservative treatment plus optic nerve decompression helped in three patients, who reported unilaterally no light-perception at admission, to regain at least partial recovery of afferent function of the visual pathway. Most of the trauma units still handle the problem of optic nerve trauma with a 'wait and see' policy. This is not regarded as an up-to-date option, since there are alternatives, and these will be outlined.

Afferent Pathways↗

PubMed1998

[Dissection of the internal carotid artery with ascending thrombosis of the ophthalmic artery as a rare differential diagnosis of post-traumatic amaurosis].

The case of a 30-year-old patient is reported who presented with a right-sided amaurosis fugax and a simultaneous frontobasal fracture that had occurred after a fall. By CT angiography and MRI angiography obstruction of the ophthalmic artery following a dissection of the internal carotid artery with ascending thrombosis could be demonstrated. There was a lack of further neurological deficits because of sufficient perfusion of the cerebral arteries by the arterial circle of the cerebrum. Among the etiological variety of types of posttraumatic amaurosis, this rare cause should be taken into consideration in the etiology, diagnosis and therapy, if appropriate.

Adult↗

PubMed1998

Single-step fronto-orbital resection and reconstruction with individual resection template and corresponding titanium implant: a new method of computer-aided surgery.

In the cranio-maxillofacial field, computer-aided surgery based on computed tomography (CT) data is becoming more and more important. Navigation systems, which allow the precise intraoperative orientation of surgical instruments, can be used for greater accuracy in determining resection margins of tumours. These techniques support ablative procedures very well, but defect reconstruction still remains a problem. In contrast, computer-aided design (CAD) and computer-aided manufacturing (CAM) systems allow the construction and fabrication of individual templates for bone resection based on coherent numerical 3-D models. The template determines the exact pathway of an oscillating saw so that the planned extent of the resection and, if necessary, also the orientation of the cutting plane are verified. An individual titanium implant is prefabricated with a geometry fitting to that of the template. This implant closes the bone defect so that the contour is reconstructed precisely and individually. This new method was used for the first time for a single-step resection of a meningioma and defect-reconstruction. The tumour which had infiltrated the frontal bone resulting in a protrusion. Fronto-orbital resection and insertion of the titanium implant worked precisely as planned, so that this method offers promising new applications in the field of computer-aided surgery.

Adult↗