Biomedical subjects

K Penkner

Publications and source records attributed to K Penkner.

5 recordsLinked to original sources

PubMed2000

The function of tensor veli palatini muscles in patients with aural symptoms and temporomandibular disorder. An EMG study.

This preliminary study investigated Myrhaug's neuromuscular hypothesis by means of audiological and electromyographic assessment. After a clinical examination of the TMJ system, the activity of the tensor veli palatini muscles in the state of rest and during swallowing was investigated in 16 patients with the help of an EMG recording, and the tube-opening function was evaluated endoscopically. Results showed that 6.25% of the patients suffered from mild joint-dysfunction (group I), 81.25% from a moderate dysfunction (group II), and 12.5% from severe dysfunction (group III). Although five patients suffered from tinnitus and 11 from fullness in the ear, both the audio- and tympanogram performed on 15 patients displayed normal recordings. Only one patient suffered from moderate sensorineural hearing loss. In the EMG recording, 11 of the 16 subjects displayed normal EMG patterns in state of rest and during swallowing contraction. In two cases, abnormal EMG recordings were obtained due to incorrect insertion of the EMG needle. The study's results indicate that spasm in the masticatory muscles of TMJ patients neither seems to cause reflex spasm of the tensor palatini muscles nor to effect significant alterations in Eustachian tube function.

Adult↗

PubMed2000

Comparison of the transfer precision of three different impression materials in combination with transfer caps for the Frialit-2 system.

Transfer of the precise position of implants to a master cast is a prerequisite for accurate and passive fit of the superstructure. Implants lack the mobility of natural teeth and, therefore, inaccurate frameworks result in stress within the mechanical parts and the implant-bone interface. Various impression methods have been described to achieve accurate reproduction of the intra-oral relation of the implants. The aim of this experimental study was to compare three different impression materials (polyether, polyvinyl siloxane, hydrocolloid) with the Frialit(R)-2 system and with the indirect technique. In addition, the use of transfer caps (TCs) to improve transfer precision was tested with all three materials. All measurements were performed using a three-dimensional (3D) co-ordinate measuring machine that is capable of locating points in space and calculating the relative distortions as angles of tilt (rot-XY, rot-XZ, rot-YZ) and 3D displacement. The results suggest that addition-silicone (a-silicone) and polyether are the materials of choice for implant transfer procedures. The use of TCs resulted in a significantly reduced rotation in the XY-plane but did not improve the absolute 3D displacement. A-silicone with the use of TCs proved to be most precise. Comparison between polyether and polyvinyl siloxane showed significant differences in the XY-rotation and the 3D displacement in favour of the silicone. Because the mean distortions between the original model and the master casts were about 100 microm, absolutely precise fit may be unattainable owing to the physical properties of the materials. Further studies will have to evaluate the amount of tolerable stress at the implant-bone interface.

Alginates↗

PubMed2000

Retrospective analysis of Frialit-2 implants in the augmented sinus.

The aim of the present study was to investigate clinical and radiographic data of patients treated with implants in the posterior maxilla in combination with sinus augmentation. Study parameters included Periotest values, radiographic analysis, and survival/success rates up to 5 years. Clinical and radiographic criteria resulted in a success rate of 92.7% for sinus implants. Radiographically, the sinus implants showed a mean coronal bone loss of 0.5 mm at 6 months and 1.2 mm at 48 months. The results showed stable periimplant parameters for sinus implants during the observation period of 5 years. The success rates showed no significant differences regarding different implant-supported treatment options for the posterior maxillary region.

Adult↗

PubMed1999

Fabricating auricular prostheses using three-dimensional soft tissue models.

This article describes a method for fabricating an auricular prosthesis. This procedure uses the contours of the soft tissue surface from computerized tomography scans to fabricate a computer-generated, side-inverted 3-dimensional soft tissue model from a solid block of polyurethane using an Endoplan milling machine. The resultant 3-dimensional soft tissue model can then be used as the basis for a wax sculpture. This procedure facilitates the planning of the prosthesis; symmetrical modeling, especially for large, hemifacial defects; and the impression, which can be made on the model itself.

Acrylic Resins↗

PubMedDate not supplied

[Results of free and vascularized bone grafts in reconstructing mandibular defects].

In 105 patients with composite resections of the mandible different reconstructive approaches were studied. In 63% the defect was bridged with metal plates alone, in 15% free grafts, and in 22% microvascular bone grafts were used. The high failure rate of free grafts (48%) was contrasted by the low rate (8%) of vascularized grafts lost. Resorption of vascularized grafts was not observed where the anastomoses remained patent.

Anastomosis, Surgical↗