Lactosorb panel and screws for repair of large orbital floor defects.

In a series of five patients with extensive fractures of the orbital floor, we used a biodegradable sheet for bridging of the bony defects. To achieve optimal support of the orbital contents in their anatomically correct position, we fixed the sheet with at least two resorbable screws to the infraorbital rim. This new technique appears to be superior to conventional methods because it offers reproducible results without the need for secondary interventions.

Computed intraoperative navigation guidance--a preliminary report on a new technique.

Objective: To assess the value of a computer-assisted three-dimensional guidance system (Virtual Patient System) in maxillofacial operations.

Design: Laboratory and open clinical study.

Setting: Teaching Hospital, Austria.

Computer-aided navigation in secondary reconstruction of post-traumatic deformities of the zygoma.

Augmented reality technology was used in 5 patients for secondary reconstruction of post-traumatic unilateral deformities of the zygomaticomaxillary complex. Three electromagnetic sensors interfaced to a computer-aided navigation system (ARTMA Biomedical Inc.) were utilized.

Solitary plasmocytoma of the mandible--a combined approach for treatment and reconstruction.

A 44-year-old man presented with a solitary plasmocytoma in the left mandible. After neoadjuvant radiation therapy and chemotherapy, a bone marrow biopsy was taken for cryopreservation. In simulation surgery, tumour resection and primary reconstruction were planned on an individual stereolithographic 3-D skull model.

Remote stereotactic visualization for image-guided surgery: technical innovation.

Additional data from imaging sources using computer navigation assistance enables virtual visualization of anatomical structures in three dimensions for stereotactic navigation during an operation. Recent developments in communication technology enable the broadcasting not only of video data, but also of stereotactic navigation data via the network. By telepresence/teleconsulting, the composite images and overlapping graphics (instrument, target structure, landmark, contour) can be seen in connected clinics, with the possibility of interactive graphic assistance.

Virtual reality for orthognathic surgery: the augmented reality environment concept.

Purpose: The objective of this study was to apply virtual reality technology to osteotomies of the facial skeleton.

Materials And Methods: Augmented reality can be considered a hybrid of virtual and real environment spaces, which are coregistered and simultaneously visualized. Using a see-through HMD (head-mounted display) and Interventional Video Tomography intraoperatively, partial visual immersion into a patient-related virtual data space augments the surgeon's perception as shown in an experimental study and clinical applications.

Horseshoe Le Fort I osteotomy in combination with endosteal implants--a median-term follow-up study.

Fourteen patients with Class VI resorption of the maxilla were treated with horseshoe Le Fort I osteotomy. In 11 cases, the procedure was followed by the placement of endosteal implants. In six patients, simultaneous placement of implants was carried out, while in five patients this was done in a second procedure.

Endosteal implants in the irradiated lower jaw.

Since 1990 Endosteal implants have been inserted in the irradiated lower jaw at our clinic. IMZ implants have been used for dental rehabilitation in 26 patients (21 male, 5 female) suffering from squamous cell carcinomas stage T2-T4 136. The implants were either placed in local bone and soft tissue (group 1, n = 60 implants), or in local bone after marginal mandibulectomy and transplanted soft tissue (group 2, n = 26 implants), or in transplanted bone and soft tissue (group 3, n = 52 implants).

Image-guided surgery.

Interventional video tomography (IVT), a new imaging modality, achieves virtual visualization of anatomic structures in three dimensions for intraoperative stereotactic navigation. Partial immersion into a virtual data space, which is orthotopically coregistered to the surgical field, enhances, by means of a see-through head-mounted display (HMD), the surgeon's visual perception and technique by providing visual access to nonvisual data of anatomy, physiology, and function. The presented cases document the potential of augmented reality environments in maxillofacial surgery.

Augmented reality environment for temporomandibular joint motion analysis.

The principles of interventional video tomography were applied for the real-time visualization of temporomandibular joint movements in an augmented reality environment. Anatomic structures were extracted in three dimensions from planar cephalometric radiographic images. The live-image fusion of these graphic anatomic structures with real-time position data of the mandible and the articular fossa was performed with a see-through, head-mounted display and an electromagnetic tracking system.

Virtual image guided navigation in tumor surgery--technical innovation.

We present a new visualization system for image-guided stereotactic navigation in tumor surgery. The combination of frameless stereotactic localization technology with real-time video processing permits the visualization of medical imaging data as a video overlay during the actual surgical procedure. Virtual computer-generated anatomical structures are displayed intraoperatively in a semi-immersive head-up display.

[Computer-assisted intraoperative visualization of dental implants. Augmented reality in medicine].

In this paper, a recently developed computer-based dental implant positioning system with an image-to-tissue interface is presented. On a computer monitor or in a head-up display, planned implant positions and the implant drill are graphically superimposed on the patient's anatomy. Electromagnetic 3D sensors track all skull and jaw movements; their signal feedback to the workstation induces permanent real-time updating of the virtual graphics' position.

[Resistance of isolated cells from squamous cell carcinomas of the oral cavity to cytotoxic drugs].

Human tumor cells from 22 patients with squamous cell carcinomas of the oral cavity were cultivated in vitro and then subjected to sensitivity tests to cytotoxic drugs such as methotrexate, 5-fluorouracil, cisplatin and bleomycin. Tumor cell proliferation showed drug-specific reaction patterns and time-dose-dependent variations. While the effect of methotrexate on cell proliferation was insignificant, 5-fluorouracil caused a growth suppression of 50%.

[Articular disk dislocation in the human TMJ].

A three-dimensional model of articular disk dislocations has been developed. Histological examination of 35 temporomandibular joints in near sagittal section reveals sometimes extreme anterior displacement in about 50% and slight posterior displacement of the disk in 6% of the specimens. In the frontal plane medial dislocation prevails in more than 70% of the 32 specimens evaluated, whereas there is only one lateral dislocation.

Lactate dehydrogenase isoenzymes in squamous cell carcinomas of the oral cavity.

Lactate dehydrogenase (LDH; EC 1.1.1.

[Conclusiveness of various diagnostic procedures for squamous cell carcinomas of the visceral cranium and the oral cavity as compared with histological evaluations].

In 60 patients with primary squamous cell carcinomas of the oral cavity, clinical examination was complemented by 5 additional diagnostic procedures prior to surgery to assess tumor extension. Comparing these finding with the histological evaluation of the excised tissue demonstrated that, while the TNM classification remains the foundation of all tumor diagnostic procedures, the use of radiography, bone scintigraphy and CT is indispensable to ascertain the amount of tissue to be excised. CT competes with B-scan sonography in cervical lymph node diagnostics.

[Compression joint as a differential diagnosis in chronic facial pain].

"Costen's syndrome" is generally used to label chronic pain in the periauricular region. This article presents the results of a post-treatment evaluation of 50 patients, 25 of whom were referred to hospital with Costen's syndrome indicated in the diagnosis. As a result of this study it is proposed that the term "compression joint" be used instead of "Costen's syndrome".

[Spheno-occipital synchondrosis--a fluorescence and polarization microscopy study in Cercopithecus aethiops monkeys].

On 17 Cercopithecus aethiops monkeys we investigated with the method of the polychromic sequential dye marking system the histomorphology as well as the dynamics of growth and calcification of the spheno-occipital synchondrosis. The age of the animals ranged from change to teeth to late adolescence. The animals had been divided into four different groups: I: late change of teeth; II: young adult; III: fully grown; IV: late adolescence.

Rehydration of lyophilised cartilage grafts sterilized by different methods.

In in vitro experiments weight increase and rehydration speed of lyophilised cartilage grafts sterilized by different methods were determined. For periods of up to 72 h the increase in weight during rehydration was measured. The methods of sterilization used is only of little significance for such weight increase.

[Perioperative treatment of patients with chronic TMJ diseases].

The concept of perioperative diagnosis and treatment of patients with chronic TMJ disease has been confirmed by a follow-up examination of ten female patients after surgical treatment. Eight of the ten patients were pain-free after observation periods of 3 to 20 months. Following an initial bite-guard splint therapy, instrumental functional analysis, MR tomography and arthrographic visualization of dynamic movement profiles are indispensable.

[Growth of oral epithelia in cell groups in vitro. Approaches and possible methods].

Various possible methods and own experimental approaches to the production of an autogenous, two-layer epithelialdermal replacement of the mucous membrane are reported. The results of the cultivation of human mucosal epithelia in vitro are presented and the basic requirements this material should meet are discussed.