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Biomedical subjects

W Schilli

Publications and source records attributed to W Schilli.

At least 19 recordsLinked to original sources

Comparison of transcutaneous incisions used for exposure of the infraorbital rim and orbital floor: a retrospective study.

One hundred and five patients were investigated for functional and aesthetic impairments following treatment of orbital trauma through subciliary, mid-lower eyelid, or infraorbital incisions. The progress of impairments with time was assessed, and the merits and shortcomings of each of the three approaches were established. The results showed that impairments persisting up to 6 months postoperatively have virtually not receded even after 6 years. The infraorbital incision showed the highest frequency of impairments, followed by the subciliary incision. The mid-lower eyelid incision showed the best results, with an impairment frequency well below those of the other two approaches. This approach seems to combine the advantages of the infraorbital incision with the unnoticeable scar formation associated with the subciliary incision.

Adolescent

[Severe atrophy of the alveolar ridge in edentulous patients. Combined treatment using bone grafts and screw implants].

In cases of advanced alveolar ridge atrophy, when the bone available for endosseous implants is not sufficient, endosseous implants are combined with augmentation of the alveolar ridge by means of autologous bone transplants. Depending on the type of atrophy found, the authors use three different surgical procedures: onlay technique, sandwich technique and alveolar extension technique. In all cases functional loading of the implants was performed by way of an entirely implant-supported bridgework. Results to date indicate that initial postoperative resorption is followed by a virtual standstill once the implants have been loaded.

Alveolar Process

[Nasal intubation for frontobasal fractures?].

In most cases the surgical management of craniofacial fractures involves a correction of the occlusion. This requires nasal intubation. In a frontobasal fracture with simultaneous CSF fistula, nasal intubation is thought to increase the risk of meningitis. An analysis of the records of 160 patients with frontobasal fractures and CSF fistulae revealed that the route of intubation had no influence on the post-operative complication rate. Nasal intubation is therefore not contraindicated in frontobasal fractures with CSF fistulae.

Cerebrospinal Fluid Rhinorrhea

Penicillin concentration in the compact bone of the mandible.

During surgical removal of impacted third molars, the concentration of Penicillin G was determined in the compact bone of the mandible. Fifteen patients received 5 million IU and 15 received 10 million IU of Penicillin G intravenously as a single dose before surgery began. In both groups concentrations of penicillin with a bactericidal effect on most pathogenically relevant oral bacteria were detected during osteotomy. Taking into account the considerable interindividual variation, the one-shot application of 10 million IU of Penicillin G was more effective in certain cases than the 5 million IU dose. The factors influencing the decision on the high single-dose application include expected length of operation, body weight, kidney function, and infusion period. Assuming that in intraoral osteotomies the bone becomes contaminated with bacteria that are highly sensitive to penicillins, the results indicate that preoperative infusion of Penicillin G could be an effective method of preventing wound infection.

Adolescent

Cultured gingival epithelium. A possible suitable material for pre-prosthetic surgery.

In cultivating gingival epithelium from people up to the age of 66 years it is possible to gain a differentiated mucosal tissue sheet that is more than 100 times the size of the original biopsy surface. The morphological characteristics are a prickle cell layer with polygonal cells and a basal cell layer with flattened cells. Desmosomes, tonofibrils and microplicae at the superficial side of the epithelium are typical features. There is a cell biological differentiation as the distinct binding of lectins and of a cytokeratin antibody proves. The multiplication in surface area, the possibility of using cells of senior patients and the morphological and cell biological differentiation of cultured gingival epithelium are advantages in its application for the autologous bridging of intraoral defects.

Acetylglucosamine

Radiation and osteosynthesis. Dosimetry on an irradiation phantom.

An irradiation phantom was used to measure dose increases using the backscatter of different materials (titanium, steel, lead, aluminium). Telecobalt-60 and 8-MV photons were used for the irradiation. The irradiation dose was measured by means of a defined X-ray film blackening. The most important parameter was to find out whether under simulated conditions, undesirable hot spots occur. We were able to demonstrate that a 12.5 to 16% increase in the radiation dose can be observed for titanium and steel at a distance of 0.45 mm from the metal specimen. A comparison between titanium and steel did not demonstrate a relevant advantage for titanium. Therefore, adjuvant percutaneous radiation therapy should not have any influence on the life of the implant, if the soft tissue layer is of sufficient thickness. The available literature is reviewed and presented in tables.

Aluminum

Interaction of osteogenic cells with hydroxylapatite implant materials in vitro and in vivo.

In a series of scanning electron microscopic studies, the reaction of osteogenic cells to hydroxylapatite (HA) implant materials was investigated in culture and following implantation. Tissue components as found in normal rat and dog bone were identified at the interface in both test systems. In vivo, implant bed cells showed an intimate contact with the HA surfaces. Osteoblasts deposited organic matrix and bone mineral in direct apposition to HA, with no evidence of encapsulation or granulation tissue. The development of such a direct spatial relationship appears to involve mechanisms more encompassing than epitaxis.

Animals

Photoelastic experiments on the implantation of a bone graft into the mandible with stable compression osteosynthesis.

The implantation of a bone graft into the mandible was simulated in photoelastic model tests. Problems posed by the lingual and alveolar areas untouched by the plate are discussed. The tests showed that in both problem areas enough interfragmentary pressure can be built up using a five-hold DC (dynamic compression) plate with a short implant and two four-hole DC plates with a long implant, whenever the metal plates have dynamic compression holes (DC), are prebent and the screws are in converging position. This is a prerequisite for a rapid revascularization of the implanted bone graft and primary bone healing. These tests and our clinical experience showed that with small implants using a five-hold plate and with long implants using two four-hole plates, and physiologically stressing the bone implant, the principles of stable compression osteosynthesis without intermaxillary immobilization have proved themselves.

Biomechanical Phenomena

[Preventive removal of displaced teeth].

Using the data acquired from our catamnestic survey, we were able to establish a broad catalogue of complications involved with impacted and displaced teeth. Given these complications, it is not medically responsible to leave impacted and displaced teeth in the jaw, even if they are asymptomatic. The risks increase considerably with age. Late operative removal of such teeth can be a dangerous intervention due to local complications such as abscesses, cysts, osteomyelitis, tumors, systemic diseases, and age-related changes in the cardiovascular system.

Adult

[Swellings in the maxillofacial region (author's transl)].

The most frequent swellings in the maxillofacial region can be traced to odontogenic inflammations. Chronic dental foci exacerbate and break through the soft tissue layer surrounding the jaw. There the purulent material quickly spreads along the muscular pocket and simulates a phlegomonous inflammation. Inflammations of the individual soft part niches have characteristic symptoms. Because of the loose interconnections the infectious material can spread very quickly into the parapharyngeal space and from there downwards into the mediastinum or upwards into the base of the skull. Because of the danger of an advance in these spaces, it will be necessary to incise the swellings on time.

Adolescent

[Standardized apical titanium pin for plugging the root canal during apicoectomy].

A new procedure for apical closure after apical root resection with a metal filling is presented which is easy to handle with appropriately standardized equipment and ensures exact apical closure. By conical preparation of the whole root, a standardized metal peg which resists distortion can be used for anchoring the crown prosthesis without further preparation. Temporarily a standardized guttapercha peg can be used for closure. Even if renewed work on the root becomes necessary later, the apical metal closure remains firm because of its wedging.

Apicoectomy

[Organic foreign bodies in the maxillary sinus].

A case was reported in which a foreign body was identified in the maxillary sinus during the course of a radiologic dental examination. The foreign body proved to be a calculus. Analysis of the calculus revealed no foreign body responsible for the crystallization. The possibility of local formation of a calculus of the maxillary antrum was discussed.

Aged